Olean Wholesale Grocery Co-Op v. Bumble Bee Foods LLC

FOR PUBLICATION

UNITED STATES COURT OF APPEALS
FOR THE NINTH CIRCUIT

OLEAN WHOLESALE GROCERY No. 19-56514
COOPERATIVE, INC., BEVERLY
YOUNGBLOOD, PACIFIC D.C. No.
GROSERVICE, INC., DBA Pitco 3:15-md-02670-
Foods, CAPITOL HILL DMS-MDD
SUPERMARKET, LOUISE ANN DAVIS
MATTHEWS, JAMES WALNUM, COLIN
MOORE, JENNIFER A. NELSON, OPINION
ELIZABETH DAVIS-BERG, LAURA
CHILDS; NANCY STILLER; BONNIE
VANDERLAAN; KRISTIN MILLICAN;
TREPCO IMPORTS AND
DISTRIBUTION, LTD.; JINKYOUNG
MOON; COREY NORRIS; CLARISSA
SIMON; AMBER SARTORI; NIGEL
WARREN; AMY JOSEPH; MICHAEL
JUETTEN; CARLA LOWN; TRUYEN
TON-VUONG, AKA David Ton; A-1
DINER; DWAYNE KENNEDY; RICK
MUSGRAVE; DUTCH VILLAGE
RESTAURANT; LISA BURR; LARRY
DEMONACO; MICHAEL BUFF; ELLEN
PINTO; ROBBY REED; BLAIR HYSNI;
DENNIS YELVINGTON; KATHY
DURAND GORE; THOMAS E.
WILLOUGHBY III; ROBERT FRAGOSO;
SAMUEL SEIDENBURG; JANELLE
ALBARELLO; MICHAEL COFFEY;
JASON WILSON; JADE CANTERBURY;
2 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

NAY ALIDAD; GALYNA
ANDRUSYSHYN; ROBERT BENJAMIN;
BARBARA BUENNING; DANIELLE
GREENBERG; SHERYL HALEY; LISA
HALL; TYA HUGHES; MARISSA
JACOBUS; GABRIELLE KURDT; ERICA
PRUESS; SETH SALENGER; HAROLD
STAFFORD; CARL LESHER; SARAH
METIVIER SCHADT; GREG STEARNS;
KARREN FABIAN; MELISSA
BOWMAN; VIVEK DRAVID; JODY
COOPER; DANIELLE JOHNSON;
HERBERT H. KLIEGERMAN; BETH
MILLINER; LIZA MILLINER; JEFFREY
POTVIN; STEPHANIE GIPSON;
BARBARA LYBARGER; SCOTT A.
CALDWELL; RAMON RUIZ; THYME
CAFE & MARKET, INC.; HARVESTERS
ENTERPRISES, LLC; AFFILIATED
FOODS, INC.; PIGGLY WIGGLY
ALABAMA DISTRIBUTING CO., INC.;
ELIZABETH TWITCHELL; TINA
GRANT; JOHN TRENT; BRIAN LEVY;
LOUISE ADAMS; MARC BLUMSTEIN;
JESSICA BREITBACH; SALLY
CRNKOVICH; PAUL BERGER;
STERLING KING; EVELYN OLIVE;
BARBARA BLUMSTEIN; MARY
HUDSON; DIANA MEY; ASSOCIATED
GROCERS OF NEW ENGLAND, INC.;
NORTH CENTRAL DISTRIBUTORS,
LLC; CASHWA DISTRIBUTING CO. OF
KEARNEY, INC.; URM STORES, INC.;
WESTERN FAMILY FOODS, INC.;
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 3

ASSOCIATED FOOD STORES, INC.;
GIANT EAGLE, INC.; MCLANE
COMPANY, INC.; MEADOWBROOK
MEAT COMPANY, INC.; ASSOCIATED
GROCERS, INC.; BILO HOLDING,
LLC; WINNDIXIE STORES, INC.;
JANEY MACHIN; DEBRA L. DAMSKE;
KEN DUNLAP; BARBARA E. OLSON;
JOHN PEYCHAL; VIRGINIA RAKIPI;
ADAM BUEHRENS; CASEY
CHRISTENSEN; SCOTT DENNIS;
BRIAN DEPPERSCHMIDT; AMY E.
WATERMAN; CENTRAL GROCERS,
INC.; ASSOCIATED GROCERS OF
FLORIDA, INC.; BENJAMIN FOODS
LLC; ALBERTSONS COMPANIES
LLC; H.E. BUTT GROCERY
COMPANY; HYVEE, INC.; THE
KROGER CO.; LESGO PERSONAL
CHEF LLC; KATHY VANGEMERT;
EDY YEE; SUNDE DANIELS;
CHRISTOPHER TODD; PUBLIX SUPER
MARKETS, INC.; WAKEFERN FOOD
CORP.; ROBERT SKAFF; WEGMANS
FOOD MARKETS, INC.; JULIE WIESE;
MEIJER DISTRIBUTION, INC.; DANIEL
ZWIRLEIN; MEIJER, INC.; SUPERVALU
INC.; JOHN GROSS & COMPANY;
SUPER STORE INDUSTRIES; W LEE
FLOWERS & CO INC.; FAMILY
DOLLAR SERVICES, LLC; AMY
JACKSON; FAMILY DOLLAR STORES,
INC.; KATHERINE MCMAHON;
DOLLAR TREE DISTRIBUTION, INC.;
4 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

JONATHAN RIZZO; GREENBRIER
INTERNATIONAL, INC.; JOELYNA A.
SAN AGUSTIN; ALEX LEE, INC.;
REBECCA LEE SIMOENS; BIG Y
FOODS, INC.; DAVID TON; KVAT
FOOD STORES, INC., DBA Food City;
AFFILIATED FOODS MIDWEST
COOPERATIVE, INC.; MERCHANTS
DISTRIBUTORS, LLC; BROOKSHIRE
BROTHERS, INC.; SCHNUCK
MARKETS, INC.; BROOKSHIRE
GROCERY COMPANY; KMART
CORPORATION; CERTCO, INC.;
RUSHIN GOLD, LLC, DBA The Gold
Rush; UNIFIED GROCERS, INC.;
TARGET CORPORATION; SIMON-
HINDI, LLC; Fareway Stores, Inc.;
Moran Foods, LLC, DBA Save-A-
Lot; WOODMAN’S FOOD MARKET,
INC.; DOLLAR GENERAL
CORPORATION; SAM’S EAST, INC.;
DOLGENCORP, LLC; SAM’S WEST,
INC.; KRASDALE FOODS, INC.;
WALMART STORES EAST, LLC; CVS
PHARMACY, INC.; WALMART STORES
EAST, LP; BASHAS’ INC.; WAL-MART
STORES TEXAS, LLC; MARC
GLASSMAN, INC.; WAL-MART
STORES, INC.; 99 CENTS ONLY
STORES; JESSICA BARTLING; AHOLD
U.S.A., INC.; GAY BIRNBAUM;
DELHAIZE AMERICA, LLC; SALLY
BREDBERG; ASSOCIATED
WHOLESALE GROCERS, INC.; KIM
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 5

CRAIG; MAQUOKETA CARE CENTER;
GLORIA EMERY; ERBERT &
GERBERT’S, INC.; ANA GABRIELA
FELIX GARCIA; JANET MACHEN;
JOHN FRICK; PAINTED PLATE
CATERING; KATHLEEN GARNER;
ROBERT ETTEN; ANDREW GORMAN;
GROUCHO’S DELI OF FIVE POINTS,
LLC; EDGARDO GUTIERREZ;
GROUCHO’S DELI OF RALEIGH;
ZENDA JOHNSTON; SANDEE’S
CATERING; STEVEN KRATKY;
CONFETTI’S ICE CREAM SHOPPE;
KATHY LINGNOFSKI; END PAYER
PLAINTIFFS; LAURA MONTOYA;
KIRSTEN PECK; JOHN PELS; VALERIE
PETERS; ELIZABETH PERRON; AUDRA
RICKMAN; ERICA C. RODRIGUEZ,
Plaintiffs-Appellees,

and

JESSICA DECKER, JOSEPH A.
LANGSTON, SANDRA POWERS,
GRAND SUPERCENTER, INC., THE
CHEROKEE NATION, US FOODS, INC.,
SYSCO CORPORATION, GLADYS,
LLC, SPARTANNASH COMPANY,
BRYAN ANTHONY REO,
Plaintiffs,

v.
6 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

BUMBLE BEE FOODS LLC; STARKIST
CO.; DONGWON INDUSTRIES CO.,
LTD.,
Defendants-Appellants,

and

KING OSCAR, INC.; THAI UNION
FROZEN PRODUCTS PCL; DEL
MONTE FOODS COMPANY; TRI
MARINE INTERNATIONAL, INC.;
DONGWON ENTERPRISES; DEL
MONTE CORP.; CHRISTOPHER D.
LISCHEWSKI; LION CAPITAL
(AMERICAS), INC.; BIG CATCH
CAYMAN LP, AKA Lion/Big Catch
Cayman LP; FRANCIS T
ENTERPRISES; GLOWFISCH
HOSPITALITY; THAI UNION NORTH
AMERICA, INC.,
Defendants.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 7

Appeal from the United States District Court
for the Southern District of California
Dana M. Sabraw, Chief District Judge, Presiding

Argued and Submitted En Banc September 22, 2021
Pasadena, California

Filed April 8, 2022

Before: Andrew J. Kleinfeld, Sidney R. Thomas, Susan P.
Graber, William A. Fletcher, Ronald M. Gould, Richard A.
Paez, Consuelo M. Callahan, Sandra S. Ikuta, Paul J.
Watford, Michelle T. Friedland and Kenneth K. Lee,
Circuit Judges.

Opinion by Judge Ikuta;
Dissent by Judge Lee
8 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

SUMMARY*

Antitrust / Class Certification

The en banc court filed an opinion affirming the district
court’s order certifying three subclasses of tuna purchasers
who alleged that the suppliers violated federal and state
antitrust laws. The en banc court held that the district court
did not abuse its discretion in concluding that the purchasers’
statistical regression model, along with other expert evidence,
was capable of showing that a price-fixing conspiracy caused
class-wide antitrust impact, thus satisfying one of the
prerequisites for bringing a class action under Federal Rule of
Civil Procedure 23(b)(3).

To take advantage of Rule 23’s procedure for aggregating
claims, plaintiffs must make two showings. First, under
Rule 23(a), they must establish that “there are questions of
law or fact common to the class,” as well as demonstrate
numerosity, typicality, and adequacy of representation.
Second, the plaintiffs must show that the class fits into one of
three categories under Rule 23(b). To qualify for the third
category, Rule 23(b)(3) the district court must find that
“questions of law or fact common to class members
predominate over any questions affecting only individual
members.”

Joining other circuits, the en banc court held that
plaintiffs must prove by a preponderance of the evidence the
facts necessary to carry the burden of establishing that the

*
This summary constitutes no part of the opinion of the court. It has
been prepared by court staff for the convenience of the reader.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 9

prerequisites of Rule 23 are satisfied. The en banc court held
that to prove a common question of law or fact that relates to
a central issue in an antitrust class action, plaintiffs must
establish that essential elements of the cause of action, such
as the existence of an antitrust violation or antitrust impact,
are capable of being established through a common body of
evidence, applicable to the whole class.

The en banc court held that in making the determinations
necessary to find that the prerequisites of Rule 23(b)(3) are
satisfied, the district court may weigh conflicting expert
testimony and resolve expert disputes. In determining
whether the “common question” prerequisite is met, the
district court is limited to resolving whether the evidence
establishes that a common question is capable of class-wide
resolution, not whether the evidence in fact establishes that
plaintiffs would win at trial. The district court must also
resolve disputes about historical facts if necessary to
determine whether the plaintiffs’ evidence is capable of
resolving a common issue central to the plaintiffs’ claims.
Therefore, the district court cannot decline certification
merely because it considers plaintiffs’ evidence relating to the
common question to be unpersuasive and unlikely to succeed
in carrying the plaintiffs’ burden of proof on that issue. Nor
can a district court decline to certify a class that will require
determination of some individualized questions at trial, so
long as such questions do not predominate over the common
questions.

The en banc court held that when individualized questions
relate to the injury status of class members, Rule 23(b)(3)
requires that the court determine whether individualized
inquiries about such matters would predominate over
common questions. Therefore, the en banc court rejected the
10 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

argument that Rule 23 does not permit the certification of a
class that potentially includes more than a de minimis number
of uninjured class members.

Beginning with the “DPP” class of direct purchasers of
the tuna suppliers’ products, such as nationwide retailers and
regional grocery stores, the panel held that in order to prevail
on their antitrust claim, the DPP class was required to prove
that the tuna suppliers engaged in a conspiracy (an antitrust
violation), which resulted in antitrust impact in the form of
higher prices paid by each member of the class, which in turn
led to measurable damages. The question whether each
member of the DPP class suffered antitrust impact was
central to the validity of each of the DPP claims. The central
questions on appeal were whether the expert evidence
presented by the DPPs was capable of resolving this issue “in
one stroke,” and whether this common question predominated
over any individualized inquiry.

The en banc court concluded that the district court did not
abuse its discretion in certifying the class. The DPPs relied
on the expert testimony and report of Dr. Russell Mangum,
whose findings about the tuna market and tuna suppliers’
collusive behavior, pricing correlation test, regression model,
and robustness checks confirmed his theory that the price-
fixing conspiracy resulted in substantial price impacts, and
that the impact was common to the DPPs during the collusion
period. The en banc court concluded that the district court
did not make any legal or factual error when, in considering
whether the DPPs’ evidence was capable of establishing
antitrust impact for the class as a whole, the district court
reviewed Dr. Mangum’s expert testimony and report, the
rebuttal testimony and report by Dr. John Johnson, and
Dr. Mangum’s reply, and then addressed the parties’ disputes.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 11

The district court thus properly concluded that Dr. Mangum’s
pooled regression model, along with other evidence, was
capable of answering the question whether there was antitrust
impact due to the collusion on a class-wide basis, thus
satisfying this prerequisite of Rule 23(b)(3).

The en banc court held that the district court did not abuse
its discretion in determining that the evidence presented by
the DPPs proved: (1) that the element of antitrust impact was
capable of being established class-wide through common
proof, and (2) that this common question predominated over
individual questions. The en banc court rejected any
categorical argument that a pooled regression model cannot
control for variables relating to the individual differences
among class members. The en banc court also rejected the
argument that, in this case, the model’s output could not
plausibly serve as common evidence for all class members
given the individual differences among those class members.
The en banc court held that the district court did not err by
failing to resolve a dispute between the parties as to whether
28 percent of the class did not suffer antitrust impact. Rather,
the district court fulfilled its obligation to resolve the disputes
raised by the parties in order to satisfy itself that the evidence
proves the prerequisites for Rule 23(b)(3), which was that the
evidence was capable of showing that the DPPs suffered
antitrust impact on a class-wide basis.

The en banc court held that the district court also did not
abuse its discretion in determining that the evidence
presented by the “CFP” class of indirect purchasers of bulk-
sized tuna products and the “EPP” class of individual end
purchasers was capable of proving the element of antitrust
impact under California’s Cartwright Act, thus satisfying the
prerequisites of Rule 23(b)(3).
12 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

Dissenting, Judge Lee, joined by Judge Kleinfeld, wrote
that the majority opinion allowed the district court to certify
a class, even though potentially about one out of three class
members suffered no injury. Judge Lee wrote that if
defendants’ econometrician expert was correct that almost a
third of the class members may not have suffered injury, then
plaintiffs did not show the predominance of common issues
under Rule 23(b). He wrote that because class action cases
almost always settle once a court certifies a class, a district
court must serve as a gatekeeper to resolve key issues
implicating Rule 23 requirements, including whether too
many putative class members suffered no injury, at the class
certification stage. Further, the majority’s rejection of a de
minimis rule, under which the number of uninjured class
members should be de minimis, created a circuit split.

COUNSEL

Gregory G. Garre (argued), Samir Deger-Sen, and Shannon
Grammel, Latham & Watkins LLP, Washington, D.C.;
Christopher S. Yates, Belinda S. Lee, and Ashley M. Bauer,
Latham & Watkins LLP, San Francisco, California; for
Defendants-Appellants StarKist Co. and Dongwon Industries
Co. Ltd.

Christopher L. Lebsock (argued), Michael P. Lehmann,
Bonny E. Sweeney, and Samantha J. Stein, Hausfeld LLP,
San Francisco, California, for Plaintiffs-Appellees Direct
Purchaser Plaintiff Class.

Jonathan W. Cuneo (argued), Joel Davidow, and Blaine
Finley, Cuneo Gilbert & Laduca LLP, Washington, D.C., for
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 13

Plaintiffs-Appellees Commercial Food Preparer Plaintiff
Class.

Thomas H. Burt (argued), Wolf Haldenstein Adler Freeman
& Herz LLP, New York, New York; Betsy C. Manifold,
Rachele R. Byrd, Marisa C. Livesay, and Brittany N. DeJong,
Wolf Haldenstein Adler Freeman & Herz LLP, San Diego,
California; for Plaintiffs-Appellees End Payer Plaintiff Class.

Corbin K. Barthold and Cory L. Andrews, Washington, D.C.,
for Amicus Curiae Washington Legal Foundation.

Ashley C. Parrish and Joshua N. Mitchell, King & Spalding
LLP, Washington, D.C.; Steven P. Lehotsky, Jonan D. Urick,
Daryl Joseffer, and Jennifer B. Dickey, United States
Chamber Litigation Center; Anne M. Voigts, Quyen L. Ta,
and Suzanne E. Nero, King & Spalding LLP, San Francisco,
California; Kerry Perigoe, King & Spalding LLP, Los
Angeles, California; Christopher A. Mohr, Software &
Information Industry Association, Washington, D.C.; Jeanine
Poltronieri, Internet Association, Washington, D.C.; for
Amici Curiae Chamber of Commerce of the United States of
America, Software Information Industry Association, and
Internet Association.

Randy M. Stutz, American Antitrust Institute, Washington,
D.C.; Professor Joshua P. Davis, University of San Francisco
School of Law, San Francisco, California; Ellen Meriwether,
Cafferty Clobes Meriwether & Sprengal, Media,
Pennsylvania; for Amicus Curiae American Antitrust
Institute.
14 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

Scott L. Nelson and Allison M. Zieve, Public Citizen
Litigation Group, Washington, D.C., for Amicus Curiae
Public Citizen Inc.

Jocelyn D. Larkin, Lindsay Nako, and David S. Nahmias,
Impact Fund, Berkeley, California, for Amici Curiae Impact
Fund, Bet Tzedek, California Rural Legal Assistance
Foundation, Centro Legal de la Raza, Legal Aid at Work, and
Public Counsel.

Karla Gilbride, Washington, D.C., as and for Amicus Curiae
Public Justice P.C.

Deborah A. Elman and Chad Holtzman, Garwin Gerstein &
Fisher LLP, New York, New York; Warren T. Burns and
Kyle K. Oxford, Burns Charest LLP, Dallas, Texas; Robert S.
Kitchenoff, President; Lin Y. Chan, Vice President,
Committee to Support the Antitrust Laws, Washington, D.C.;
for Amicus Curiae Committee to Support the Antitrust Laws.

Jonathan F. Cohn, Joshua J. Fougere, and Jacquelyn E.
Fradette, Sidley Austin LLP, Washington, D.C., for Amicus
Curiae Consumer Healthcare Products Association.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 15

OPINION

IKUTA, Circuit Judge:

The primary suppliers of packaged tuna in the United
States appeal the district court’s order certifying three classes
of tuna purchasers who allege the suppliers violated federal
and state antitrust laws. The main issue on appeal is whether
the purchasers’ statistical regression model, along with other
expert evidence, is capable of showing that a price-fixing
conspiracy caused class-wide antitrust impact, thus satisfying
one of the prerequisites for bringing a class action under Rule
23(b)(3) of the Federal Rules of Civil Procedure. Because the
district court did not abuse its discretion in concluding that
Rule 23(b)(3) was satisfied, we affirm.

I

Bumble Bee,1 StarKist, and Chicken of the Sea (COSI),
and their parent companies are the largest suppliers of
packaged tuna in the United States (referred to collectively as
the “Tuna Suppliers”). Their products include packaged tuna
sold to direct purchasers like Costco and Walmart, and food-
service-size tuna products sold to various distributors for
resale. Together, the Tuna Suppliers sell over 80 percent of
the packaged tuna in the country.

In late 2015, the United States Department of Justice
(DOJ) opened an investigation into the packaged tuna

1
As a result of Appellant Bumble Bee Foods LLC’s bankruptcy
proceeding, appellate proceedings against Bumble Bee Foods have been
held in abeyance due to the automatic stay imposed by 11 U.S.C. § 362.
Dkt. No. 51.
16 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

industry for violations of federal antitrust law. The DOJ
investigation uncovered evidence of a price-fixing scheme
among the Tuna Suppliers, which led the DOJ to enter
multiple indictments alleging a criminal conspiracy to fix
prices of canned tuna for the period from approximately
November 2011 through December 2013. Bumble Bee,
StarKist, and three tuna industry executives pleaded guilty to
the conspiracy. Bumble Bee’s former CEO was convicted by
a jury of a conspiracy to fix prices.2 COSI cooperated with
the DOJ and admitted to price fixing in exchange for
leniency.

A number of purchasers of the Tuna Suppliers’ products
(referred to collectively as the “Tuna Purchasers”) filed
putative class actions against the Tuna Suppliers alleging
violations of various federal and state antitrust laws. The
Tuna Purchasers alleged that the Tuna Suppliers engaged in
a conspiracy from November 2010 through at least December
31, 2016 to fix prices of tuna, along with other collusive
activities in furtherance of the price-fixing conspiracy. The
Tuna Purchasers alleged that they were damaged by the

2
Plea Agreement, United States v. Bumble Bee Foods LLC, No.
3:17-cr-00249-EMC (N.D. Cal. Aug. 2, 2017), ECF No. 32; Plea
Agreement, United States v. Worsham, No. 3:16-cr-00535-EMC (N.D.
Cal. Mar. 15, 2017), ECF No. 14; Plea Agreement, United States v.
Cameron, No. 3:16-cr-00501-EMC (N.D. Cal. Jan. 25, 2017), ECF No.
18; Plea Agreement, United States v. Hodge, No. 3:17-cr-00297-EMC
(N.D. Cal. June 28, 2017), ECF No. 13; Plea Agreement, United States v.
StarKist Co., No. 3:18-cr-00513-EMC (N.D. Cal. Nov. 14, 2018),
ECF No. 24.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 17

conspiracy because they paid supra-competitive prices for the
Tuna Suppliers’ products.3

The Tuna Purchasers’ actions were consolidated in a
multidistrict litigation pretrial proceeding in the Southern
District of California. The Tuna Purchasers consist of three
putative subclasses: (i) direct purchasers of the Tuna
Suppliers’ products, such as nationwide retailers and regional
grocery stores, who purchased packaged tuna between June
1, 2011 and July 1, 2015 (the “DPPs”); (ii) indirect
purchasers of the Tuna Suppliers’ products who bought bulk-
sized tuna products between June 2011 and December 2016
for prepared food or resale (the “CFPs”); and (iii) individual
end purchasers who bought the Tuna Suppliers’ products
between June 1, 2011 and July 1, 2015 for personal
consumption (the “EPPs”).

In 2018, the Tuna Purchasers moved to certify the three
subclasses under Rule 23 of the Federal Rules of Civil
Procedure to proceed as a class action. See Fed. R. Civ. P.
23(a), (b)(3). To demonstrate class-wide antitrust impact,
each subclass proffered evidence from a different economist,
each of whom employed substantially similar methodologies,
to show that each member of the subclasses had paid an
overcharge caused by the Tuna Suppliers’ conspiracy. The
Tuna Suppliers contested this expert evidence through their
own economists. The district court held a three-day
evidentiary hearing on the certification motion, and heard

3
Supra-competitive prices are those prices elevated “above
competitive levels” by a market participant who “exercise[s] [its] market
power” to do so. ABA Section of Antitrust Law, Econometrics: Legal,
Practical, and Technical Issues 252 (2d ed. 2014) (“Econometrics”).
18 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

substantial testimony from each expert witness. In July 2019,
the district court certified all three subclasses.

The Tuna Suppliers timely appealed, and a panel of this
court vacated the district court’s order and remanded. See
Olean Wholesale Grocery Coop., Inc. v. Bumble Bee Foods
LLC, 993 F.3d 774, 794 (9th Cir. 2021), reh’g en banc
granted, 5 F.4th 950 (9th Cir. 2021). We took the case en
banc to consider whether the district court erred in finding
that each subclass satisfied the requirement that “questions of
law or fact common to class members predominate over any
questions affecting only individual members.” Fed. R. Civ.
P. 23(b)(3).

We have jurisdiction under 28 U.S.C. § 1292(e) and
Rule 23(f) of the Federal Rules of Civil Procedure. We
review the decision to certify a class and “any particular
underlying Rule 23 determination involving a discretionary
determination” for an abuse of discretion. Yokoyama v.
Midland Nat’l Life Ins. Co., 594 F.3d 1087, 1091 (9th Cir.
2010). We review the district court’s determination of
underlying legal questions de novo, id., and its determination
of underlying factual questions for clear error, see Ruiz
Torres v. Mercer Canyons Inc., 835 F.3d 1125, 1132 (9th Cir.
2016). The Supreme Court has indicated that a court’s
determination regarding what a statistical regression model
may prove or is capable of proving is not a question of fact,
even though there may be disputed issues of fact raised by
“the data contained within an econometric model.” Comcast
Corp. v. Behrend, 569 U.S. 27, 36 n.5 (2013). Accordingly,
we review the district court’s determination that a statistical
regression model, along with other expert evidence, is
capable of showing class-wide impact, thus satisfying one of
the prerequisites of Rule 23(b)(3) of the Federal Rules of
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 19

Civil Procedure, for an abuse of discretion. See Yokoyama,
594 F.3d at 1091.

II

A

Rule 23 provides a procedural mechanism for “a federal
court to adjudicate claims of multiple parties at once, instead
of in separate suits.” Shady Grove Orthopedic Assocs., P.A.
v. Allstate Ins. Co., 559 U.S. 393, 408 (2010). As a claims-
aggregating device, Rule 23 “leaves the parties’ legal rights
and duties intact and the rules of decision unchanged,” id.,
and it does not affect the substance of the claims or plaintiffs’
burden of proof, see 28 U.S.C. § 2072(b).

To take advantage of Rule 23’s procedure for aggregating
claims, plaintiffs must make two showings. First, the
plaintiffs must establish “there are questions of law or fact
common to the class,” as well as demonstrate numerosity,
typicality and adequacy of representation.4 Fed. R. Civ. P.

4
Rule 23(a) provides:

Prerequisites. One or more members of a class may sue
or be sued as representative parties on behalf of all
members only if:

(1) the class is so numerous that joinder of all
members is impracticable;

(2) there are questions of law or fact common to
the class;
20 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

23(a). A common question “must be of such a nature that it
is capable of classwide resolution—which means that
determination of its truth or falsity will resolve an issue that
is central to the validity of each one of the claims in one
stroke.” Wal-Mart Stores, Inc. v. Dukes, 564 U.S. 338, 350
(2011). By contrast, an individual question is one where
members of a proposed class will need to present evidence
that varies from member to member. See Tyson Foods, Inc.
v. Bouaphakeo, 577 U.S. 442, 453 (2016).

Second, the plaintiffs must show that the class fits into
one of three categories. See Fed. R. Civ. P. 23(b). To qualify
for the third category, Rule 23(b)(3), the district court must
find that “the questions of law or fact common to class
members predominate over any questions affecting only
individual members, and that a class action is superior to
other available methods for fairly and efficiently adjudicating
the controversy.” Fed. R. Civ. P. 23(b)(3).5 “The
predominance inquiry asks whether the common,

(3) the claims or defenses of the representative
parties are typical of the claims or defenses of the
class; and

(4) the representative parties will fairly and
adequately protect the interests of the class.
5
Rule 23(b)(3) provides in pertinent part:

A class action may be maintained if Rule 23(a) is
satisfied and if . . . (3) the court finds that the questions
of law or fact common to class members predominate
over any questions affecting only individual members,
and that a class action is superior to other available
methods for fairly and efficiently adjudicating the
controversy.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 21

aggregation-enabling, issues in the case are more prevalent or
important than the non-common, aggregation-defeating,
individual issues.” Tyson Foods, 577 U.S. at 453 (cleaned
up). The requirements of Rule 23(b)(3) overlap with the
requirements of Rule 23(a): the plaintiffs must prove that
there are “questions of law or fact common to class members”
that can be determined in one stroke, see Wal-Mart, 564 U.S.
at 349, in order to prove that such common questions
predominate over individualized ones, see Tyson Foods,
577 U.S. at 453–54. Therefore, courts must consider cases
examining both subsections in performing a Rule 23(b)(3)
analysis.

B

Before it can certify a class, a district court must be
“satisfied, after a rigorous analysis, that the prerequisites” of
both Rule 23(a) and 23(b)(3) have been satisfied. Gen. Tel.
Co. of Sw. v. Falcon, 457 U.S. 147, 161 (1982); Comcast,
569 U.S. at 35. “[P]laintiffs wishing to proceed through a
class action must actually prove—not simply plead—that their
proposed class satisfies each requirement of Rule 23,
including (if applicable) the predominance requirement of
Rule 23(b)(3),” and must carry their burden of proof “before
class certification.” Halliburton Co. v. Erica P. John Fund,
Inc., 573 U.S. 258, 275–76 (2014).

We have not yet prescribed the plaintiffs’ burden for
proving that the prerequisites of Rule 23 are satisfied. In the
absence of direction from Congress or the Constitution, it is
up to the court to prescribe the burden of proof. See Herman
& MacLean v. Huddleston, 459 U.S. 375, 389–90 (1983). To
do so, we must consider both the allocation of “the risk of
error between the litigants” and “the relative importance
22 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

attached to the ultimate decision.” Id. at 389 (quoting
Addington v. Texas, 421 U.S. 418, 423 (1979)). The
preponderance of the evidence standard allows both parties to
“share the risk of error in roughly equal fashion,” id. at 390
(quoting Addington, 421 U.S. at 423), while “[a]ny other
standard expresses a preference for one side’s interests,” id.
Therefore, the preponderance of the evidence standard is
“generally applicable in civil actions.” Id. By contrast, the
Court has “required proof by clear and convincing evidence
where particularly important individual interests or rights are
at stake,” such as termination of parental rights or involuntary
commitment proceedings. Id. at 389.

Applying this test here, the balance of interests in this
case favors prescribing the preponderance of the evidence
standard. The Supreme Court has made clear that Rule 23 is
consistent with the Rules Enabling Act and does not “abridge,
enlarge or modify any substantive right.” Shady Grove,
559 U.S. at 406–07 (citing 28 U.S.C. § 2072(b)). Rule 23
does not “change plaintiffs’ separate entitlements to relief nor
abridge defendants’ rights” and, instead, alters “only how the
claims are processed.” Id. at 408. Therefore, the Supreme
Court has concluded that the authorization of class actions is
substantively neutral, even though it may expose defendants
to the imposition of aggregate liability. Id. Because the
application of Rule 23 to certify a class does not alter the
defendants’ rights or interests in a substantive way, there is
no basis for applying a heightened standard of proof beyond
the traditional preponderance standard. We therefore join our
sister circuits in concluding that plaintiffs must prove the
facts necessary to carry the burden of establishing that the
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 23

prerequisites of Rule 23 are satisfied by a preponderance of
the evidence.6

In carrying the burden of proving facts necessary for
certifying a class under Rule 23(b)(3), plaintiffs may use any
admissible evidence. See Tyson Foods, 577 U.S. at 454–55
(explaining that admissibility of evidence at certification must
meet all the usual requirements of admissibility and citing to
Rules 401, 403, and 702 of the Federal Rules of Evidence).
Plaintiffs frequently offer expert evidence, including
statistical evidence or class-wide averages, to prove that they
meet the prerequisites of Rule 23(b)(3). See id. at 455.
Where, as here, a defendant did not raise a Daubert challenge
to the expert evidence before the district court,7 the defendant
forfeits the ability to argue on appeal that the evidence was
inadmissible, but may still argue that the evidence is not
capable of answering a common question on a class-wide
basis. See Comcast, 569 U.S. at 32 n.4; Tyson Foods,
577 U.S. at 458–59.

In order for the plaintiffs to carry their burden of proving
that a common question predominates, they must show that
the common question relates to a central issue in the

6
See In re Lamictal Direct Purchaser Antitrust Litig., 957 F.3d 184,
191 (3d Cir. 2020); In re Nexium Antitrust Litig., 777 F.3d 9, 27 (1st Cir.
2015); Messner v. Northshore Univ. HealthSystem, 669 F.3d 802, 811 (7th
Cir. 2012); Alaska Elec. Pension Fund v. Flowserve Corp., 572 F.3d 221,
228 (5th Cir. 2009); Teamsters Loc. 445 Freight Div. Pension Fund v.
Bombardier Inc., 546 F.3d 196, 202 (2d Cir. 2008).
7
In a class proceeding, defendants may challenge the reliability of an
expert’s evidence under Daubert v. Merrell Dow Pharmaceuticals, Inc.,
509 U.S. 579 (1993), and Rule 702 of the Federal Rules of Evidence. See
Tyson Foods, 577 U.S. at 459; see also Comcast, 569 U.S. at 32 n.4.
24 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

plaintiffs’ claim. See Wal-Mart, 564 U.S. at 349–50.
Therefore, “[c]onsidering whether ‘questions of law or fact
common to class members predominate’ begins, of course,
with the elements of the underlying cause of action.” Erica
P. John Fund, Inc. v. Halliburton Co., 563 U.S. 804, 809
(2011) (quoting Fed. R. Civ. P. 23(b)(3)).

The claims at issue here are violations of section 1 of the
Sherman Antitrust Act, 15 U.S.C. § 15, and California’s
Cartwright Act, Cal. Bus. & Prof. Code §§ 16700 et seq.8
The elements of a claim for such antitrust action are (i) the
existence of an antitrust violation; (ii) “antitrust injury” or
“impact” flowing from that violation (i.e., the conspiracy);
and (iii) measurable damages. See Big Bear Lodging Ass’n
v. Snow Summit, Inc., 182 F.3d 1096, 1101–02 (9th Cir.
1999); In re Hydrogen Peroxide Antitrust Litig., 552 F.3d
305, 311 (3d Cir. 2008), as amended (Jan. 16, 2009) (citing
15 U.S.C. § 15). “Antitrust injury” is “injury of the type the
antitrust laws were intended to prevent and that flows from
that which makes defendants’ acts unlawful.” Brunswick
Corp. v. Pueblo Bowl-O-Mat, Inc., 429 U.S. 477, 489 (1977).
Damages are measured only after each plaintiff has
demonstrated that the defendant’s conduct caused the plaintiff

8
The DPPs claim a violation of the Sherman Act, while the CFPs and
the EPPs allege violations of California’s antitrust law, the Cartwright Act,
Cal. Bus. & Prof. Code, § 16700 et seq. The elements of a Cartwright Act
claim are “(1) the formation and operation of the conspiracy, (2) the
wrongful act or acts done pursuant thereto, and (3) the damage resulting
from such act or acts.” Marsh v. Anesthesia Servs. Med. Grp., Inc.,
132 Cal. Rptr. 3d 660, 670–71 (Cal. Ct. App. 2011) (cleaned up). Because
the analysis of a claim under the Cartwright Act “mirrors the analysis
under federal [antitrust] law,” we do not consider the Cartwright Act
claims separately from the federal antitrust claims. County of Tuolumne
v. Sonora Cmty. Hosp., 236 F.3d 1148, 1160 (9th Cir. 2001).
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 25

to suffer an antitrust injury. See In re Hydrogen Peroxide,
552 F.3d at 311.

Therefore, to prove there is a common question of law or
fact that relates to a central issue in an antitrust class action,
plaintiffs must establish that “essential elements of the cause
of action,” such as the existence of an antitrust violation or
antitrust impact, are capable of being established through a
common body of evidence, applicable to the whole class. Id.
(cleaned up). Here, the Tuna Purchasers claim that they can
establish the existence of antitrust impact through common
proof.

C

In making the determinations necessary to find that the
prerequisites of Rule 23(b)(3) are satisfied, the district court
must proceed “just as the judge would resolve a dispute about
any other threshold prerequisite for continuing a lawsuit.” In
re Initial Pub. Offerings Sec. Litig., 471 F.3d 24, 42 (2d Cir.
2006), decision clarified on denial of reh’g, 483 F.3d 70 (2d
Cir. 2007). This means that the court must make a “rigorous
assessment of the available evidence and the method or
methods by which plaintiffs propose to use the [class-wide]
evidence to prove” the common question in one stroke. In re
Hydrogen Peroxide, 552 F.3d at 312. In addition, the court
must find that this common question (i.e., the “common,
aggregation-enabling” issue) predominates over individual
issues. Tyson Foods, 577 U.S. at 453. The determination
whether expert evidence is capable of resolving a class-wide
question in one stroke may include “[w]eighing conflicting
expert testimony” and “[r]esolving expert disputes,” In re
Hydrogen Peroxide, 552 F.3d at 323–24, where necessary to
ensure that Rule 23(b)(3)’s requirements are met and the
26 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

“common, aggregation-enabling” issue predominates over
individual issues, Tyson Foods, 577 U.S. at 453.9

In determining whether the “common question”
prerequisite is met, a district court is limited to resolving
whether the evidence establishes that a common question is
capable of class-wide resolution, not whether the evidence in
fact establishes that plaintiffs would win at trial. While such
an analysis may “entail some overlap with the merits of the
plaintiff’s underlying claim,” Wal-Mart, 564 U.S. at 351, the

9
Not all expert evidence is capable of resolving a class-wide issue in
one stroke. Cf. Dissent at 70–71. Courts have frequently found that
expert evidence, while otherwise admissible under Daubert, was
inadequate to satisfy the prerequisites of Rule 23. For instance, a class did
not meet the prerequisites of Rule 23 where the expert evidence was
inadequate to prove an element of the claim for the entire class, see Wal-
Mart, 564 U.S. at 354, 356, 359 (holding that class members failed to
establish existence of common question with respect to Title VII claims
because they “provide[d] no convincing proof of a companywide
discriminatory pay and promotion policy”); where the damages evidence
was not consistent with the plaintiffs’ theory of liability, see Comcast, 569
U.S. at 35 (holding that at the class certification stage, “any model
supporting a plaintiff’s damages case must be consistent with its liability
case”); where the evidence contained unsupported assumptions, see In re
New Motor Vehicles Canadian Exp. Antitrust Litig., 522 F.3d 6, 29 (1st
Cir. 2008) (criticizing the unsupported assumption that, absent the
defendants’ anti-competitive conduct, there would have been an influx of
cars from Canada to United States sufficient to substantially decrease
national prices); or where the evidence demonstrated nonsensical results
such as false positives, i.e., injury to class members who could not
logically have been injured by a defendant’s conduct, see In re Rail
Freight Fuel Surcharge Antitrust Litig.-MDL No. 1869 (Rail Freight I),
725 F.3d 244, 252–55 (D.C. Cir. 2013) (vacating a certification order
where the plaintiffs’ expert evidence predicted that certain plaintiffs had
been injured by a price-fixing conspiracy even though they operated under
fixed-price contracts and were not exposed to overcharges caused by the
conspiracy).
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 27

“[m]erits questions may be considered [only] to the extent []
that they are relevant to determining whether the Rule 23
prerequisites for class certification are satisfied,” Amgen Inc.
v. Conn. Ret. Plans & Tr. Funds, 568 U.S. 455, 466 (2013);
see also Ellis v. Costco Wholesale Corp., 657 F.3d 970, 983
n.8 (9th Cir. 2011). “Rule 23 grants courts no license to
engage in free-ranging merits inquiries at the certification
stage.” Amgen, 568 U.S. at 466.

A district court must also resolve disputes about historical
facts if necessary to determine whether the plaintiffs’
evidence is capable of resolving a common issue central to
the plaintiffs’ claims.10 For instance, in a case in which a
nationwide class of plaintiff employees alleged nationwide
discrimination by their employer, we held that a district court
had to resolve factual disputes at certification regarding
whether decisions regarding promotions were made at the
local level or by upper management. See Ellis, 657 F.3d at
983–84 & n.7. We reasoned that if such decisions were made
only at the local level, plaintiffs “would face an exceedingly
difficult challenge in proving that there are questions of fact
and law common to the nationwide class.” Id. at 983–84.
Nevertheless, the district court was not required to resolve
factual disputes regarding ultimate issues on the merits, such
as “whether women were in fact discriminated against” or
whether the defendant “does in fact have a culture of gender
stereotyping and paternalism.” Id. at 983; see also id. at 983
n.8. Resolving such issues would “put the cart before the
horse” by requiring plaintiffs to show at certification that they
will prevail on the merits. Amgen, 568 U.S. at 460.

10
The district court’s findings at the certification stage “do not bind
the fact-finder on the merits.” In re Hydrogen Peroxide, 552 F.3d at 318.
28 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

Therefore, a district court cannot decline certification
merely because it considers plaintiffs’ evidence relating to the
common question to be unpersuasive and unlikely to succeed
in carrying the plaintiffs’ burden of proof on that issue. See
id. at 459–60. Rather, Tyson Foods established the rule that
if “each class member could have relied on [the plaintiffs’
evidence] to establish liability if he or she had brought an
individual action,” and the evidence “could have sustained a
reasonable jury finding” on the merits of a common question,
Tyson Foods, 577 U.S. at 455, then a district court may
conclude that the plaintiffs have carried their burden of
satisfying the Rule 23(b)(3) requirements as to that common
question of law or fact.11 In Tyson Foods, for instance, the
Court held that if the class members had pursued individual
lawsuits, each could have relied on the expert evidence
purporting to show how long it took to don and doff
protective equipment. Tyson Foods, 577 U.S. at 456–57.
Accordingly, the Court concluded that such expert evidence
was capable of answering a common question for the entire
class in one stroke, and could reasonably sustain a jury

11
Senne v. Kansas City Royals Baseball Corp. referenced Tyson
Foods’s rule that a district court may deny the use of admissible expert
evidence to meet the requirements of Rule 23(b)(3) only if “‘no
reasonable juror’ could find it probative of whether an element of liability
was met,” and then stated in passing that “Tyson expressly cautioned that
this rule should be read narrowly and not assumed to apply outside of the
wage and hour context.” 934 F.3d 918, 947 & n.27 (9th Cir. 2019) (citing
Tyson Foods, 577 U.S. at 459–60). But Tyson Foods contains no such
limitation; rather, it declined to adopt “broad and categorical rules
governing the use of representative and statistical evidence in class
actions,” and indicated that district courts should evaluate the sufficiency
of plaintiffs’ evidence on a case-by-case basis, depending on the purpose
for which the expert evidence is being introduced and the underlying
cause of action. 577 U.S. at 459–60. Accordingly, we disapprove this
dictum in Senne, 934 F.3d at 947 n.27.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 29

verdict in favor of the plaintiffs, even though a jury could still
decide that the evidence was not persuasive. Id. at 459–60;
see also id. at 457 (explaining that the question whether the
expert’s “study was unrepresentative or inaccurate” was
“itself common to the claims made by all class members”).
The rule that the evidence need merely be capable of
resolving a common question on a class-wide basis holds true
whether the common question concerns an element of
plaintiffs’ claim, see Amgen, 568 U.S. at 468–69 (materiality
in a Rule 10b-5 action), or a fact that must be determined to
establish liability, see Tyson Foods, 577 U.S. at 450 (time
spent donning and doffing protective equipment per week).

Nor can a district court decline to certify a class that will
require determination of some individualized questions at
trial, so long as such questions do not predominate over the
common questions. See Fed. R. Civ. P. 23(b)(3). “When one
or more of the central issues in the action are common to the
class and can be said to predominate, the action may be
considered proper under Rule 23(b)(3) even though other
important matters will have to be tried separately, such as
damages or some affirmative defenses peculiar to some
individual class members.” Tyson Foods, 577 U.S. at 453
(internal quotation marks omitted). Thus, Halliburton
concluded that so long as plaintiffs could show that their
evidence is capable of proving the prerequisites for invoking
the presumption of reliance (a key element in a securities
class action) on a class-wide basis, the fact that the
defendants would have the opportunity at trial to rebut that
presumption as to some of the plaintiffs did not raise
individualized questions sufficient to defeat predominance.
573 U.S. at 276. “That the defendant might attempt to pick
off the occasional class member here or there through
30 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

individualized rebuttal does not cause individual questions to
predominate.” Id.

When individualized questions relate to the injury status
of class members, Rule 23(b)(3) requires that the court
determine whether individualized inquiries about such
matters would predominate over common questions. See
Cordoba v. DIRECTV, LLC, 942 F.3d 1259, 1277 (11th Cir.
2019).12 In an analogous context, we have held that a district
court is not precluded from certifying a class even if plaintiffs
may have to prove individualized damages at trial, a
conclusion implicitly based on the determination that such
individualized issues do not predominate over common ones.
Vaquero v. Ashley Furniture Indus., Inc., 824 F.3d 1150,
1155 (9th Cir. 2016); see also Pulaski & Middleman, LLC v.
Google, Inc., 802 F.3d 979, 988 (9th Cir. 2015); In re
Urethane, 768 F.3d 1245, 1255 (10th Cir. 2014) (“The
presence of individualized damages issues” does not preclude
a court from certifying a class because “[c]lass-wide proof is
not required for all issues”).

Therefore, we reject the dissent’s argument that Rule 23
does not permit the certification of a class that potentially
includes more than a de minimis number of uninjured class
members. Dissent at 77. This position is inconsistent with
Rule 23(b)(3), which requires only that the district court
determine after rigorous analysis whether the common

12
Because the Supreme Court has clarified that “[e]very class
member must have Article III standing in order to recover individual
damages,” TransUnion LLC v. Ramirez, 141 S. Ct. 2190, 2208 (2021),
Rule 23 also requires a district court to determine whether individualized
inquiries into this standing issue would predominate over common
questions, see Cordoba, 942 F.3d at 1277.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 31

question predominates over any individual questions,
including individualized questions about injury or entitlement
to damages. See Fed. R. Civ. P. 23(b)(3).13

A district court is in the best position to determine
whether individualized questions, including those regarding
class members’ injury, “will overwhelm common ones and
render class certification inappropriate under Rule 23(b)(3).”
Halliburton, 573 U.S. at 276; see also Ruiz Torres, 835 F.3d
at 1137 (stating that “the district court is well situated to
winnow out” a fortuitously non-injured subset of class
members). We “uphold a district court’s determination that
falls within a broad range of permissible conclusions.” Hung
Lam v. City of San Jose, 869 F.3d 1077, 1084 (9th Cir. 2017)

13
The dissent focuses on policy reasons why district courts should
refrain from certifying classes that may include more than a de minimis
number of uninjured class members. Dissent at 64, 75, 77–78. But we are
bound to apply Rule 23(b)(3) as written, regardless of policy preferences.
And contrary to the dissent’s assertion, our conclusion that courts must
apply Rule 23(b)(3) on a case-by-case basis, rather than rely on a per se
rule that a class cannot be certified if it includes more than a de minimis
number of uninjured class members, is consistent with the approach taken
by our sister circuits. Dissent at 78. Neither of the two cases cited by the
dissent, In re Rail Freight Fuel Surcharge Antitrust Litig.-MDL No. 1869
(Rail Freight II), 934 F.3d 619 (D.C. Cir. 2019) and In re Asacol Antitrust
Litig., 907 F.3d 42 (1st Cir. 2018), adopted a per se rule. Rather, based on
the particular facts of the cases before them, our sister circuits held that
Rule 23(b)(3)’s predominance requirement is not satisfied when the need
to identify uninjured class members “will predominate and render an
adjudication unmanageable.” In re Asacol Antitrust Litig., 907 F.3d at
53–54; see also Rail Freight II, 934 F.3d at 625 (holding that a district
court did not abuse its discretion in denying class certification where the
plaintiffs “proposed no further way—short of full-blown, individual trials”
to determine the common question of whether class members were
injured).
32 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

(quoting Kode v. Carlson, 596 F.3d 608, 612 (9th Cir.
2010)).14

III

We now turn to the Tuna Suppliers’ arguments and
consider them in light of this legal framework. We begin
with the DPP class, which is the focus of the Tuna Suppliers’

14
Nevertheless, a court must consider whether the possible presence
of uninjured class members means that the class definition is fatally
overbroad. When “a class is defined so broadly as to include a great
number of members who for some reason could not have been harmed by
the defendant’s allegedly unlawful conduct, the class is defined too
broadly to permit certification.” Messner, 669 F.3d at 824; see also Mazza
v. Am. Honda Motor Co., 666 F.3d 581, 596 (9th Cir. 2012) (holding that
the class definition in a false advertising action was fatally overbroad
where many members learned that the advertising was misleading before
purchase or had never been exposed to the allegedly misleading
advertisements); In re Asacol, 907 F.3d at 55–58 (holding that the class
did not meet Rule 23(b)(3) requirements because the plaintiffs’ evidence
showed that thousands of plaintiffs who were loyal to brand-name drugs
would not have purchased the generic drugs that were the subject of the
price-fixing conspiracy). In such a case, the court may redefine the
overbroad class to include only those members who can rely on the same
body of common evidence to establish the common issue. See, e.g.,
Mazza, 666 F.3d at 596 (holding that false advertising “class must be
defined in such a way as to include only members who were exposed to
advertising that is alleged to be materially misleading”). A court may not,
however, create a “fail safe” class that is defined to include only those
individuals who were injured by the allegedly unlawful conduct. See Ruiz
Torres, 835 F.3d at 1138 n.7 (internal quotation marks omitted). “Such
a class definition is improper because a class member either wins or, by
virtue of losing, is defined out of the class and is therefore not bound by
the judgment.” Messner, 669 F.3d at 825. But, ultimately, the problem
of a potentially “over-inclusive” class “can and often should be solved by
refining the class definition rather than by flatly denying class certification
on that basis.” Id.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 33

arguments. In order to prevail on their antitrust claim, the
DPP class must prove that the Tuna Suppliers engaged in a
conspiracy (an antitrust violation), which resulted in antitrust
impact in the form of higher prices paid by each member of
the class, which in turn led to measurable damages. The
question whether each member of the DPP class suffered
antitrust impact “is central to the validity of each one of the
[DPP] claims.” Wal-Mart, 564 U.S. at 350. The central
questions on appeal are whether the expert evidence
presented by the DPPs is capable of resolving this issue “in
one stroke,” id., and whether this common question
predominates over any individualized inquiry. We conclude
that the district court did not abuse its discretion in certifying
the class.

A

The centerpiece of the DPPs’ claim that each member of
the class suffered antitrust impact is economist Dr. Russell
Mangum’s expert testimony and report. According to his
testimony and report, Dr. Mangum reviewed a comprehensive
range of available information to develop an understanding of
the nature of the market at issue and the details of the Tuna
Suppliers’ price-fixing conspiracy. That information
included court filings, the Tuna Suppliers’ guilty pleas,
discovery materials such as the Tuna Suppliers’ business
records concerning their sales of packaged tuna, deposition
testimony, publicly available information regarding the tuna
industry, and data regarding supply and demand factors that
affect the manufacture, sale and consumption of packaged
tuna such as raw material prices and details about customer
preferences.
34 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

After examining the economic structure of the tuna
market and the available record evidence concerning the Tuna
Suppliers’ behavior, Dr. Mangum determined that the
packaged tuna market was conducive to price-fixing, given
the Tuna Suppliers’ dominance in the market, the attendant
barriers to entry for competitors, the Tuna Suppliers’ use of
price lists for their products, and other characteristics of the
packaged tuna industry. According to Dr. Mangum, these
findings supported a baseline economic theory that the Tuna
Suppliers’ collusive behavior would affect the DPPs on a
class-wide basis. Dr. Mangum then used a number of
different econometric tools to evaluate whether quantitative
evidence supported this theory.15

Dr. Mangum first performed a pricing correlation test,
which demonstrated that the prices of the Tuna Suppliers’
products moved up or down together regardless of product or
customer type, and thus supported the proposition that the
Tuna Suppliers’ collusion had a common, supra-competitive
impact on their prices. Based on this evidence, Dr. Mangum
concluded that the Tuna Suppliers’ collusion would result in
higher prices that would affect direct purchasers on a class-
wide basis, which was consistent with his original theory.
This finding is also consistent with “the prevailing
[economic] view [that] price-fixing affects all market
participants, creating an inference of class-wide impact even
when prices are individually negotiated.” In re Urethane,
768 F.3d at 1254.

15
Econometrics is “the application of statistical methods to economic
data . . . to draw inferences about economic relationships from observed
data on market outcomes [i.e., price], even when those outcome are the
result of complex interactions among numerous economic forces.”
Econometrics at 1.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 35

To further explore whether the DPPs were subject to an
overcharge caused by the price-fixing conspiracy (rather than
by other variables that could affect prices) on a class-wide
basis, Dr. Mangum constructed a statistical model using a
multiple regression analysis. Regression analyses are used to
determine “the relationship between an unknown [dependent]
variable [such as price] and one or more independent
variables [e.g., transaction characteristics, and supply and
demand factors] that are thought to impact the dependent
variable.” Id. at 1260 (quotation marks omitted) (citing
Michael J. Saks, et al., Reference Manual on Scientific
Evidence 179, 181 (2d ed. 2000)). If a regression model uses
“appropriate independent [or explanatory] variables,” it can
test and isolate the extent to which the actual prices paid by
plaintiffs are higher because of a defendant’s collusive
behavior. Id. Assuming Dr. Mangum’s regression model met
this standard, it could provide further evidence that the DPPs
were impacted by the Tuna Suppliers’ collusion on a class-
wide basis.

In simple terms, Dr. Mangum first aggregated (or
“pooled”) the actual tuna sale transaction data for the Tuna
Suppliers’ sales to the DPPs during both the alleged
conspiracy period and during benchmark periods before and
after the conspiracy. Dr. Mangum then identified a number
of variables (referred to as independent or explanatory
variables) that could affect the price of tuna, including
product characteristics, input costs, customer type, and
variables related to consumer preference and demand, such as
disposable income, seasonal effects, and geography. The
model then isolated (or “controlled for”) the effect of these
explanatory variables on the prices paid by DPPs, which
allowed the model to isolate the effect that the conspiracy by
itself had on the prices paid by DPPs. When all the tuna sale
36 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

transactions were aggregated, and the explanatory variables
(other than the price-fixing conspiracy) were controlled for,
the model showed that the DPPs paid 10.28 percent more for
tuna during the conspiracy period than they did during the
benchmark periods. Dr. Mangum labeled this 10.28 percent
as the “overcharge,” meaning the common amount paid by
the DPPs resulting from the collusive behavior alone. This
result was statistically significant, meaning that there was a
less than five percent chance that the higher prices during the
price-fixing conspiracy was a product of chance. Thus, by
isolating the common overcharge amount, Dr. Mangum’s
regression model was further confirmation of his theory that
the Tuna Suppliers’ collusion had a class-wide effect. 16

Dr. Mangum performed several tests (which he referred
to as “robustness checks”) to confirm that his regression
model was an appropriate tool to be used by the entire DPP
class to show common impact. These tests were used to
confirm the reliability of the model, and, according to
Dr. Mangum, the test results supported his ultimate
conclusion that the model could be used to show class-wide

16
The dissent argues that Dr. Mangum’s opinion is not persuasive
because large retailers have bargaining power and can extract price
discounts, promotional credits, and rebates. Dissent at 72–73. As the
dissent concedes, Dissent at 73 & n. 5, Dr. Mangum took these issues into
account (to the extent that the Tuna Suppliers provided relevant data).
After doing so, Dr. Mangum ran the regression model using both gross
and net prices and determined that his regression model continued to
produce a statistically significant overcharge. Dr. Mangum therefore
reasoned that discounts and promotions did not affect his pooled model or
his conclusion of class-wide impact. Although the dissent argues that (in
the dissent’s view) Dr. Mangum did not consider price discounts,
promotional credits, and rebates “adequately,” Dissent at 73 & n. 5, the
persuasiveness of Dr. Mangum’s analysis is not at issue at this phase of
the proceeding.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 37

injury. First, Dr. Mangum changed the model to evaluate the
overcharge specific to each individual defendant. The results
showed that prices were still elevated above competitive
levels during the collusion period. Second, Dr. Mangum
changed the model to evaluate the overcharge specific to
certain products with different characteristics, such as fish
type and package type. These tests showed that each type of
product tested was impacted to a similar degree. Third,
Dr. Mangum changed the model to evaluate the overcharge
based on customer types.17 This test showed that there were
large, statistically significant overcharges for every customer
type. These robustness checks confirmed Dr. Mangum’s
theory that the DPPs paid an overcharge during the
conspiracy period. Finally, Dr. Mangum used the output of
the pooled regression model to predict the but-for prices (i.e.,
what the price of tuna during the conspiracy period would
have been without the overcharge caused by the conspiracy),
and compared these predicted but-for prices to the actual
prices paid by the DPP class. This comparison showed that
94.5 percent of the purchasers had at least one purchase
above the predicted but-for price, which again provided
further evidence that the conspiracy had a common impact on
all or nearly all the members of the DPP class.18 Dr. Mangum

17
Direct purchasers were grouped into categories called customer
types, which included Retail, Club, Special Market, Food Service, Mass
Merchandise, Discount, and e-Commerce.
18
According to Dr. Mangum, the purpose of this robustness test was
to demonstrate that his regression model was sound. Contrary to the
dissent’s assertion, Dissent at 66, Dr. Mangum did not “suggest” that
5.5 percent of the class were uninjured. Rather, Dr. Mangum concluded
that each class member was injured by supra-competitive prices, and used
a different methodology for calculating damages for each member of the
class. See infra at n.19. The Tuna Suppliers do not develop the argument
38 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

therefore concluded that his aggregated regression model
provided econometric evidence that the conspiracy resulted
in higher prices paid by all or nearly all DPPs. According to
Dr. Mangum, the results were strong evidence of common,
class-wide antitrust impact.19

In sum, Dr. Mangum’s findings about the tuna market and
the Tuna Suppliers’ collusive behavior, his pricing correlation
test, his regression model, and his robustness checks all
confirmed his theory that the conspiracy resulted in
substantial price impacts, and that the impact was common to
the DPPs during the collusion period.

B

The Tuna Suppliers attacked Dr. Mangum’s expert report
on multiple fronts, but primarily relied on their rebuttal
expert, economist Dr. John Johnson, who made multiple
criticisms of Dr. Mangum’s methodology. The essence of

that the results of this robustness test preclude certification of the class as
currently defined. Therefore, we do not address this issue here. See
United States v. Sineneng-Smith, 140 S. Ct. 1575, 1578 (2020); see also
Tyson Foods, 577 U.S. at 460 (declining to reach a similar issue).
19
Although the regression model primarily served as evidence of
class-wide antitrust impact, Dr. Mangum used the overcharge derived
from the regression model to estimate class-wide damages. This estimate
was developed by multiplying the overcharge estimate of 10.28 percent by
the appropriate sales volume for the defendants, adjusted by several
pertinent factors. Dr. Mangum used the same method to estimate damages
for each of the class representatives identified in the complaint. The Tuna
Suppliers do not challenge Dr. Mangum’s damages methodology. Thus,
the dissent’s contention that the court has created a “sweeping rule that
gives a free pass to the intractable problem of highly individualized
damages analyses” misses the mark. Dissent at 74.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 39

Dr. Johnson’s critique was that it was not statistically
appropriate to use a pooled regression model for transactions
in the tuna market, given the multiple individualized
differences among class members, such as disparities in
negotiating tactics and bargaining power. Dr. Mangum’s use
of pooled data, Dr. Johnson alleged, masked these individual
differences among class members. Thus, Dr. Johnson
claimed, Dr. Mangum’s conclusion that the conspiracy had a
class-wide impact based on a uniform overcharge did not
reflect the real world.

Dr. Johnson supported this allegation on several grounds.
First, Dr. Johnson claimed that a statistical tool called a Chow
test20 shows that the data relating to tuna transactions should
not be pooled due to individual differences in each
purchaser’s transactions. Second, Dr. Johnson criticized
Dr. Mangum’s calculation that 94.5 percent of DPPs whose
transactional data were included in the model had at least one
purchase at a price above the predicted but-for price.
According to Dr. Johnson, this calculation was misleading
because it was premised on what Dr. Johnson characterized
as the faulty assumption that all direct purchasers paid the
same 10.28 percent overcharge throughout the proposed class
period. Instead, Dr. Johnson performed his own test of
Dr. Mangum’s model. As part of this test, Dr. Johnson
changed the model to evaluate overcharge based on each
individual customer. According to Dr. Johnson, the test
showed that of the 604 direct purchasers who bought from the
Tuna Suppliers during the proposed class period, the model
did not estimate a positive and statistically significant

20
A Chow test is a statistical test designed to “determine whether it
is appropriate to pool potential subgroups when estimating the average
effect of the alleged conspiracy.” Econometrics at 358.
40 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

overcharge (attributable to the conspiracy) for 169 direct
purchasers (or 28 percent). Therefore, Dr. Johnson argued
that the plaintiffs could not rely on the model to demonstrate
class-wide impact of the conspiracy.21

Dr. Johnson made several additional critiques in arguing
that Dr. Mangum’s model was not capable of demonstrating
class-wide impact. First, Dr. Johnson argued that
Dr. Mangum’s model showed false positives. According to
Dr. Johnson, an application of Dr. Mangum’s regression
model showed that several DPP class members had paid an
overcharge when they purchased tuna products from non-
defendants, i.e., tuna suppliers who had not participated in the
conspiracy. Second, Dr. Johnson attacked the reliability of
Dr. Mangum’s model because Dr. Mangum’s model selected
time periods that did not precisely match the class periods in
the DPPs’ complaint. Finally, Dr. Johnson criticized
Dr. Mangum’s use of a cost index (a calculated measure of
costs for all the Tuna Suppliers) as one of the explanatory
variables in his model, rather than using actual accounting
cost data. According to Dr. Johnson, the use of a cost index
inappropriately assumed that the Tuna Suppliers’ costs
responded in a like way to supply and demand factors.

In rebuttal, Dr. Mangum rejected Dr. Johnson’s premise
that a pooled, aggregated model was inappropriate to use in

21
Dr. Johnson’s test attempted to show that Dr. Mangum’s model was
flawed because 169 direct purchasers could not rely on the model to show
antitrust impact due to the fact (as Dr. Mangum subsequently explained)
that some purchasers had no or too few transactions during the pre-
collusion benchmark period to generate statistically significant results.
Contrary to the dissent’s claim, Dissent at 66, Dr. Johnson did not show
that 28 percent of the class potentially suffered no injury. See infra
Section IV.B.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 41

this case. Dr. Mangum explained that his technique was a
well-known and well-accepted method for examining
antitrust impact in markets with individualized differences
among purchasers. According to Dr. Mangum, both of the
bases for Dr. Johnson’s challenges to the use of a pooled
regression model failed. First, Dr. Mangum claimed that a
Chow test should not be used in the manner employed by
Dr. Johnson in his report. According to Dr. Mangum,
Dr. Johnson’s Chow test was “designed to fail,” meaning that
in this context, the test results would always show that the
data relating to tuna transactions should not be pooled.
Second, Dr. Mangum asserted that the record contained
insufficient transaction data for Dr. Johnson’s test of the
regression model to yield meaningful results. For example,
Dr. Mangum acknowledged that the model, as changed by
Dr. Johnson to consider purchasers on an individual basis,
could not estimate a positive and statistically significant
overcharge for 169 direct purchasers. But according to
Dr. Mangum, no regression model could yield a statistically
significant estimate for many of those 169 direct purchasers
on such an individual purchaser-by-purchaser basis, because
61 of those purchasers did not make any purchases during the
benchmark periods, and many of the other purchasers had not
undertaken a sufficient number of transactions during either
the benchmark periods or collusion period to yield
statistically significant results. And logically, Dr. Mangum
asserted, given the evidence that the defendants were able to
inflate prices generally through the conspiracy, that the tuna
market was susceptible to collusion, and that the model
showed a robust, statistically significant impact of the price-
fixing scheme on the tuna market, even the DPP class
members for whom Dr. Johnson’s test did not yield a
positive, statistically significant overcharge should be able to
rely on the pooled regression model as evidence of impact.
42 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

Therefore, according to Dr. Mangum, Dr. Johnson erred in
concluding that the regression model had no relevance for
that 28 percent of class members.

Dr. Mangum also rebutted Dr. Johnson’s additional
critiques. With respect to Dr. Johnson’s claim that the
regression model yielded false positives, Dr. Mangum
explained that overcharges imposed by non-defendant tuna
suppliers (who were not part of the conspiracy) were not false
positives but were caused by the “umbrella effect.” This term
refers to an economic observation that when many suppliers
engage in a conspiracy to raise prices, non-conspirators may
raise their prices to supra-competitive levels because of the
conspirator’s dominant market power. See ABA Section of
Antitrust Law, Proving Antitrust Damages: Legal &
Economic Issues 226 (2d ed. 2010). Dr. Mangum also argued
that Dr. Johnson’s claim of false positives was based on an
erroneous analysis of the tuna market. According to
Dr. Mangum, Dr. Johnson incorrectly claimed that two of the
individual DPPs (Sysco and U.S. Foods) purchased tuna from
non-defendant suppliers because both of those class members
actually purchased tuna that was produced by the Tuna
Suppliers and merely sold through a middleman.
Dr. Mangum defended his selection of time periods relating
to the model, claiming he narrowed the class period based on
his analysis of the evidence in the case. Finally, Dr. Mangum
rejected Dr. Johnson’s critique of his use of cost indexes.
Dr. Mangum asserted that costs indexes were statistically
superior to using individual cost accounting data. He noted
that one of the robustness tests he performed on the data
showed that using defendant-specific cost structures
confirmed the results of the pooled model. And he asserted
that it was preferable to use his cost index for determining
competitive market prices based on market supply and
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 43

demand conditions, rather than relying on cost data derived
from the Tuna Suppliers’ individual approaches to cost
accounting.

C

In considering whether the DPPs’ evidence was capable
of establishing antitrust impact for the class as a whole, the
district court reviewed Dr. Mangum’s expert testimony and
report, the rebuttal testimony and report by Dr. Johnson, and
Dr. Mangum’s reply, and then addressed the parties’ disputes.
In doing so, the district court did not make any legal or
factual error.

First, the district court considered Dr. Johnson’s argument
that Dr. Mangum’s pooled regression model masked
differences between purchasers, and that when the overcharge
is determined for individual DPP class members the model
did not show a positive, statistically significant impact for
some 28 percent of the class. After reviewing each of the
experts’ analyses, the district court credited Dr. Mangum’s
rebuttal of Dr. Johnson’s critique. Even if the model (when
modified by Dr. Johnson to evaluate individual purchasers)
did not yield a positive, statistically significant overcharge for
some purchasers who had no or too few transactions during
the pre-collusion benchmark period, the district court
concluded that those purchasers could still rely on the pooled
regression model as evidence of the conspiracy’s impact on
similarly situated class members. The court further noted that
other evidence in the record, including the guilty pleas and
market characteristics, showed that class members suffered a
common impact.
44 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

The district court also considered Dr. Johnson’s argument
that the Chow test showed that Dr. Mangum’s model cannot
be applied to all defendants. The court acknowledged that
failure of a statistical test used to determine whether a
regression is appropriate should be taken seriously, and could
lead a court to reject the model at the class certification stage
as not capable of providing class-wide proof. But it also
noted that most regressions models will fail one or more tests
if enough are run, even if the model itself is statistically
sound. Because there was a rational basis for Dr. Mangum’s
use of the pooled regression model to demonstrate class-wide
impact, the court concluded the failure of the Chow test did
not require the court to reject the model.

The district court rejected Dr. Johnson’s additional
arguments. With respect to Dr. Johnson’s claim that the false
positives in Dr. Mangum’s model rendered the model
unreliable, the court credited Dr. Mangum’s explanation that
the false positives could be explained by the umbrella effect
and that Dr. Johnson had erroneously concluded that some
tuna was supplied by non-defendants when in fact the tuna
was supplied by defendants. The district court also addressed
the dispute over Dr. Mangum’s selection of the time period
for the class, and concluded that Dr. Mangum’s narrowing of
the time frame bolstered the reliability of the model. Finally,
the district court rejected Dr. Johnson’s critique of
Dr. Mangum’s use of a cost index, rather than actual
accounting cost data. The court credited Dr. Mangum’s
explanation as to why the use of such an index provided more
reliable results than actual cost accounting data, and
concluded that his use of a cost index did not undermine the
reliability of his methodology or model.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 45

After resolving each dispute between the experts, the
district court acknowledged that the defendants’ critique of
Dr. Mangum’s model could be persuasive to a jury at trial.
But the district court recognized that at this stage of the
proceedings, its task was to determine whether Dr. Mangum’s
evidence was capable of showing class-wide impact, not to
reach a conclusion on the merits of the DPPs’ claims. After
weighing the evidence put forth by the DPPs, including the
regression model, the correlation tests, the record evidence
and the guilty pleas and admissions entered in this case, the
district court concluded there was sufficient evidence to show
common questions predominated as to common impact.
Therefore, it ruled that this prerequisite to Rule 23(b)(3) was
met.

We conclude that the district court did not abuse its
discretion in reaching this conclusion. The court conducted
a rigorous analysis of the expert evidence presented by the
parties. The district court did not err legally or factually in
concluding that Dr. Mangum’s pooled regression model,
along with other evidence, is capable of answering the
question whether there was antitrust impact due to the
collusion on a class-wide basis, thus satisfying this
prerequisite of Rule 23(b)(3).

IV

We now turn to the Tuna Suppliers’ claims that the
district court abused its discretion in determining that the
evidence presented by the DPPs proved: (1) that the element
of antitrust impact is capable of being established class-wide
46 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

through common proof, and (2) that this common question
predominates over individual questions.22

A

The Tuna Suppliers’ main argument is that the district
court abused its discretion in determining that Dr. Mangum’s
model is capable of proving common impact for all class
members. According to the Tuna Suppliers, Dr. Mangum’s
evidence is not a permissible method of proving class-wide
liability because the regression model uses “averaging
assumptions,” meaning that the model assumes that all DPPs
were overcharged by the same uniform percentage
(10.28 percent). These averaging assumptions, according to
the Tuna Suppliers, “paper over” individualized differences
among class members. Because the tuna market is
characterized by individualized negotiations and different
bargaining power among the purchasers, the Tuna Suppliers
claim it is fundamentally impossible to show common proof
of injury. To support this argument, the Tuna Suppliers note
that the DPPs who pursued their antitrust claims individually
did not rely on a pooled regression model but used actual cost
data and claimed an individualized overcharge rate. Given
the nature of the tuna market, the Tuna Suppliers conclude,

22
The Tuna Suppliers do not challenge the district court’s
gatekeeping function under Daubert, to ensure that Dr. Mangum’s
evidence was not “statistically inadequate or based on implausible
assumptions.” Tyson Foods, 577 U.S. at 459. And contrary to the
dissent’s argument, Dissent at 69, the district court did not merely
determine that Dr. Mangum’s evidence was admissible under Daubert.
Rather, it subjected the evidence to a rigorous examination with full
consideration of Dr. Johnson’s critique. Therefore, the dissent’s assertion
that the district court committed the same error as the district court in Ellis
is misplaced. Dissent at 68–69.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 47

Dr. Mangum’s model cannot meet the prerequisites of
Rule 23(b)(3).

To the extent that the Tuna Suppliers argue that pooled
regression models involve improper “averaging assumptions”
and therefore are inherently unreliable when used to analyze
complex markets, we disagree. In antitrust cases, regression
models have been widely accepted as a generally reliable
econometric technique to control for the effects of the
differences among class members and isolate the impact of
the alleged antitrust violations on the prices paid by class
members.23 See, e.g., Econometrics at 1. Further, Tyson
Foods rejected any categorical exclusion of representative24
or statistical evidence. 577 U.S. at 459–60. Therefore, any
categorical argument that a pooled regression model cannot
control for variables relating to the individualized differences
among class members must be rejected.

23
See, e.g., Kleen Prod. LLC v. Int’l Paper Co., 831 F.3d 919, 929
(7th Cir. 2016); In re Urethane, 768 F.3d at 1263; Cordes & Co. Fin.
Servs. v. A.G. Edwards & Sons, Inc., 502 F.3d 91, 97, 107 (2d Cir. 2007);
Hemmings v. Tidyman’s Inc., 285 F.3d 1174, 1188–89 (9th Cir. 2002); In
re Linerboard Antitrust Litig., 305 F.3d 145, 153 (3d Cir. 2002).
24
Although the Tuna Suppliers refer to Dr. Mangum’s regression
model as “representative evidence,” that term is imprecise. As explained
in Tyson Foods, representative evidence generally refers to a sample that
represents the class as a whole. See 577 U.S. at 454–55. Thus, Tyson
Foods concluded that each individual in a class could rely on exemplars
of persons donning and doffing protective equipment to prove the amount
of time each spent donning and doffing; this sample was claimed to be
representative of all members of the class. See id. By contrast, a
regression model analyzes available data to determine the degree to which
a known variable, such as collusion, affected an unknown variable, such
as price, while eliminating the effect of other variables.
48 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

To the extent the Tuna Suppliers and the dissent raise the
more focused argument that, in this case, the model’s output
(estimating that the Tuna Suppliers’ conspiracy resulted in a
10.28 percent overcharge for the entire class) cannot
plausibly serve as common evidence for all class members
given the individualized differences among those class
members, we again disagree.25 It is not implausible to
conclude that a conspiracy could have a class-wide impact,
“even when the market involves diversity in products,
marketing, and prices,” especially “where, as here, there is
evidence that the conspiracy artificially inflated the baseline
for price negotiations.” In re Urethane, 768 F.3d at 1254–55.
As the Tenth Circuit explained, a district court could
reasonably conclude “that price-fixing would have affected
the entire market, raising the baseline prices for all buyers.”
Id. at 1255. In other words, it is both logical and plausible
that the conspiracy could have raised the baseline prices for
all members of the class by roughly ten percent. The district
court did not abuse its discretion in so concluding.

The dissent argues that Dr. Mangum’s expert opinion
“flies against common sense and empirical evidence,”
because large retailers like Walmart likely would have used
their bargaining power to negotiate lower prices, and thus
may not have paid higher prices because of the Tuna
Suppliers’ collusion. Dissent at 72. But the district court is
not free to prefer its own views about the economics of the

25
To the extent the Tuna Suppliers challenged the model’s inputs, the
district court considered and rejected Dr. Johnson’s critique that some of
the model’s inputs (i.e., the use of a cost index and Dr. Mangum’s
selection of time periods) rendered the model incapable of demonstrating
class-wide impact. Cf. In re Lamictal, 957 F.3d at 194 (holding that the
district court abused its discretion in certifying class because it failed to
scrutinize each expert’s data).
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 49

tuna market over the statistical evidence submitted by the
plaintiffs, and here the regression model controlled for the
variables identified by the dissent. Indeed, Dr. Mangum
provided an individualized overcharge estimate for Walmart
when he changed the model to evaluate the overcharge based
on customer types. This test showed that Walmart paid
statistically significant overcharges because of the
conspiracy. Provided that the evidence is admissible and,
after rigorous review, determined to be capable of
establishing antitrust impact on a class-wide basis, it is for the
jury, not the court, to decide the persuasiveness of
Dr. Mangum’s evidence in light of “common sense and
empirical evidence.”

The Tuna Suppliers rely on In re New Motor Vehicles
Canadian Export Antitrust Litigation, 522 F.3d 6 (1st Cir.
2008), for the proposition that a market involving
individualized negotiations is inherently incompatible with
common impact. This reliance is misplaced.26 In New Motor
Vehicles, plaintiffs raised a “novel and complex” theory of
how consumers were injured by defendants’ alleged
horizontal conspiracy to discourage imports of lower-cost
cars from Canada into the United States. Id. at 27. Plaintiffs’
theory proceeded in two steps: (1) “but for the defendants’
illegal stifling of competition,” manufacturers would have set
lower prices to compete with Canadian imports; and
(2) because the manufacturers did not do so, consumers paid
higher retail prices. Id. The First Circuit rejected this theory

26
As a threshold matter, the First Circuit held in New Motor Vehicles
that the district court lacked federal jurisdiction over the plaintiffs’ claims,
but went on to provide its thoughts on certification of the class in the event
the district court exercised its discretion to exert supplemental jurisdiction
over the state damages claims. 522 F.3d at 17.
50 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

because plaintiffs failed to demonstrate they had an approach
for proving either step. For the first step, plaintiffs had not
shown how they would establish that but for the horizontal
conspiracy, enough lower-priced Canadian cars would flood
into the American market so as to cause manufacturers to
decrease their prices. Id. As for the second step, the
plaintiffs had not proved their damages model was capable of
showing “which consumers were impacted by the alleged
antitrust violation and which were not.” Id. at 28. In this
regard, the plaintiffs relied on an inference that “any upward
pressure on national pricing would necessarily raise the prices
actually paid by individual consumers.” Id. at 29. But the
First Circuit rejected this inference because “[t]oo many
factors play into an individual negotiation to allow an
assumption—at least without further theoretical
development—that any price increase or decrease will always
have the same magnitude of effect on the final price paid.”
Id. at 29 (emphasis added). The court contrasted the
plaintiffs’ unsupported inference with cases allowing “a
presumption of class-wide impact in price-fixing cases when
‘the price structure in the industry is such that nationwide the
conspiratorially affected prices at the wholesale level
fluctuated within a range which, though different in different
regions, was higher in all regions than the range which would
have existed in all regions under competitive conditions.’”
Id. (quoting In re Linerboard Antitrust Litig., 305 F.3d 145,
151 (3d Cir. 2002)). Despite rejecting the plaintiffs’ theory
at an early stage of the case, the court did not rule out
certification of a class but instead concluded that “more work
remained to be done in the building of plaintiffs’ damages
model and the filling out of all steps of plaintiffs’ theory of
impact.” Id.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 51

As this explanation of the case makes clear, New Motor
Vehicles’ analysis is not applicable here. First, the DPPs’
price-fixing theory is not “novel” or “complex.” Id. at 27.
Rather than adopting a theory requiring multiple speculative
steps, the DPPs have a simple one-step theory: the Tuna
Suppliers conspired to raise tuna prices, resulting in higher
prices for all buyers. Second, while the plaintiffs in New
Motor Vehicles had not provided a thorough explanation or
developed a model showing how they would establish their
theory, id. at 29, the DPPs have already offered well-
developed expert testimony and regression modeling
supporting common impact. The other cases relied on by the
Tuna Suppliers are equally inapposite. See, e.g., Blades v.
Monsanto Co., 400 F.3d 562, 572 (8th Cir. 2005) (affirming
denial of class certification because evidence of a conspiracy
to raise prices, without more, could not demonstrate impact
across highly localized and highly individualized markets for
hundreds of seed varieties, and the plaintiffs had not offered
a common method of showing injury); Robinson v. Tex. Auto.
Dealers Ass’n, 387 F.3d 416, 423 (5th Cir. 2004) (reversing
class certification where the plaintiffs lacked a plausible
theory of how the challenged conduct had consistently
affected purchase prices).

The Tuna Suppliers also argue that because the individual
plaintiffs pursuing their own antitrust claims showed
overcharges both above and below the overcharge indicated
by Dr. Mangum’s model, a uniform 10.28 percent overcharge
is implausible. We also reject this argument, because it
improperly conflates the question whether evidence is
capable of proving an issue on a class-wide basis with the
question whether the evidence is persuasive. A lack of
persuasiveness is not fatal at certification. See Amgen,
568 U.S. at 459–60. For purposes of determining whether
52 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

each member of the DPP class can rely on the model to prove
antitrust impact, it is irrelevant whether actual sales data
shows a specific class member was overcharged by more or
less than 10.28 percent. Rather, the question is whether each
member of the class can rely on Dr. Mangum’s model to
show antitrust impact of any amount. The district court did
not abuse its discretion in finding that each member could.
While individualized differences among the overcharges
imposed on each purchaser may require a court to determine
damages on an individualized basis, see supra Section III.C,
such a task would not undermine the regression model’s
ability to provide evidence of common impact. Accordingly,
we reject the Tuna Suppliers’ argument that the regression
model could not sustain liability in individual proceedings.
Rather, “each class member could have relied on [the model]
to establish liability if he or she had brought an individual
action.” See Tyson Foods, 577 U.S. at 455. We therefore
conclude that the district court did not err legally or factually
in concluding that Dr. Mangum’s pooled regression model
does not fail on any of the grounds raised by the Tuna
Suppliers.27

B

The Tuna Suppliers and the dissent next contend that the
district court erred by failing to resolve a dispute between the
parties as to whether 28 percent of the class did not suffer

27
The Tuna Suppliers do not “specifically and distinctly” raise the
argument that the district court abused its discretion in resolving
challenges to the inputs to the model which were raised below, such as
Dr. Mangum’s choice of benchmark period and use of cost indexes, so
that argument is deemed forfeited on appeal. United States v. Kama,
394 F.3d 1236, 1238 (9th Cir. 2005).
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 53

antitrust impact. Instead of resolving the dispute between the
parties’ experts, the Tuna Suppliers claim, the district court
improperly shifted the critical inquiry to the jury. In other
words, the Tuna Suppliers argue that to satisfy Rule
23(b)(3)’s predominance requirement, plaintiffs must prove
that all or nearly all class members were in fact injured by the
alleged conspiracy, i.e., suffered antitrust impact.28

In raising this argument, the Tuna Suppliers focus on
Dr. Johnson’s critique of Dr. Mangum’s model, which stated
that when he tested Dr. Mangum’s model by changing it to
evaluate the overcharge specific to each individual member
of the DPP class, the test showed that 28 percent of the DPPs
could not rely on the model to show an overcharge
attributable to the conspiracy. According to the Tuna
Suppliers, this evidence indicated that 28 percent of the DPP
class did not suffer antitrust impact. And in district court, the
Tuna Suppliers argued that “28% of a class—nearly one-
third—far exceeds the de minimis number of uninjured class
members that some courts have permitted in certifying a
class.” Therefore, the Tuna Suppliers argue that the class
should not have been certified. Further, the Tuna Suppliers
argue that the existence of a large number of uninjured class
members raises a question as to whether the class has Article
III standing. The Tuna Suppliers contend that because the
class cannot be certified (and there are Article III issues) if
Dr. Johnson’s analysis is correct, the district court abused its
discretion in failing to resolve the dispute regarding whether

28
Because the Tuna Suppliers’ primary argument on appeal is that the
DPPs failed to prove class-wide antitrust impact, we understand the Tuna
Suppliers’ reference to injury as referring to antitrust impact, an element
of the class antitrust claims, not that the class members would not be able
to prove that they suffered monetary damages.
54 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

Dr. Johnson’s conclusions about Dr. Mangum’s model were
correct.

We disagree. First, the Tuna Suppliers and the dissent
mischaracterize the import of Dr. Johnson’s critique.
Dr. Johnson did not make a factual finding that 28 percent of
the DPP class or 169 class members were uninjured. Instead,
Dr. Johnson’s test was aimed at undermining confidence in
Dr. Mangum’s pooled regression model, because class
members with no or limited transactions during the
benchmark period could not rely on the model to show that
they suffered overcharges. At most, this critique supports the
more attenuated argument that Dr. Mangum’s model is
unreliable, or would be unpersuasive to a jury. But the
district court considered and resolved this methodological
dispute between the experts in favor of Dr. Mangum by
crediting his rebuttal that even class members with limited
transactions during the class period can rely on the pooled
regression model as evidence of impact on similarly situated
class members. In other words, the district court determined
that Dr. Mangum’s pooled regression model was capable of
showing that the DPP class members suffered antitrust impact
on a class-wide basis, notwithstanding Dr. Johnson’s critique.
This was all that was necessary at the certification stage. The
DPP class did not have to “first establish that it will win the
fray” in order to gain certification under Rule 23(b)(3).
Amgen, 568 U.S. at 460. Nor is this a case such as Ellis, in
which the court had to resolve a dispute regarding an issue of
historical fact in order to determine whether the challenged
discriminatory conduct could affect a class as a whole. See
657 F.3d at 983. There is no factual dispute that the Tuna
Suppliers engaged in a price-fixing scheme affecting the
entire packaged tuna industry nation-wide.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 55

The district court’s conclusion that the Tuna Suppliers
could present Dr. Johnson’s critique at trial did not
improperly shift the burden of determining whether the Rule
23(b)(3) prerequisites were met to the jury.29 See Amgen,
568 U.S. at 459–60, 466. The district court fulfilled its
obligation to resolve the disputes raised by the parties in
order to satisfy itself that the evidence proves the
prerequisites for Rule 23(b)(3), which is that the evidence
was capable of showing that the DPPs suffered antitrust
impact on a class-wide basis. “Reasonable minds may differ
as to whether the [overcharge Dr. Mangum] calculated is
probative” as to all purchasers in the class, but that is a
question of persuasiveness for the jury once the evidence is
sufficient to satisfy Rule 23. See Tyson Foods, 577 U.S.
at 459.

Neither Dr. Mangum’s pooled regression model nor
Dr. Johnson’s critique required individualized inquiries into
the class members’ injuries. If the jury found that
Dr. Mangum’s model was reliable, then the DPPs would have
succeeded in showing antitrust impact on a class-wide basis,
an element of their antitrust claim. On the other hand, if the
jury were persuaded by Dr. Johnson’s critique, the jury could
conclude that the DPPs had failed to prove antitrust impact on

29
The Tuna Suppliers do not “specifically and distinctly” develop the
argument that the district court failed to resolve the parties’ dispute as to
whether the evidence generated false positives. Kama, 394 F.3d at 1238.
In any event, as explained above, Dr. Mangum rebutted these critiques by
reference to the umbrella effect, and by claiming that Dr. Johnson’s
analysis was itself flawed because Dr. Johnson thought DPP class
members had purchased non-defendant tuna, when they actually
purchased tuna supplied by defendants. The district court did not abuse
its discretion in resolving this issue by crediting Dr. Mangum’s rebuttal.
56 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

a class-wide basis.30 In neither case would the litigation raise
individualized questions regarding which members of the
DPP class had suffered an injury. Although such issues
would have to be addressed at the damages stage, the
dissent’s argument that the district court here erred by failing
to determine whether questions of individualized damages
predominate, Dissent at 74, misses the mark. As noted above,
the Tuna Suppliers have not argued that the complexity of
damages calculations would defeat predominance here, and
as previously explained, there is no per se rule that a district
court is precluded from certifying a class if plaintiffs may
have to prove individualized damages at trial.31

We need not consider the Tuna Suppliers’ argument that
the possible presence of a large number of uninjured class
members raises an Article III issue, because the Tuna
Purchasers have demonstrated that all class members have

30
Although Dr. Johnson argued that Dr. Mangum’s pooled regression
model was unreliable and so could not sustain a jury finding of antitrust
injury to the entire DPP class, the evidence adduced at trial may
nevertheless sustain a jury finding of antitrust injury to all or part of the
class.
31
In any event, Dr. Mangum’s proposal for calculating damages is a
straightforward process of applying the class-wide overcharge to the Tuna
Purchasers’ net sales records. See supra n.19. That proposal does not
give rise to a concern about individualized mini-trials to determine each
class member’s damage award. “That the defendant might attempt to pick
off the occasional class member here or there through individualized
rebuttal does not cause individual questions to predominate.” Halliburton,
573 U.S. at 276.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 57

standing here.32 A plaintiff is required to establish the
elements necessary to prove standing “with the manner and
degree of evidence required at the successive stages of the
litigation.” Lujan v. Defs. of Wildlife, 504 U.S. 555, 561
(1992). Here, the district court concluded that the DPPs’
evidence was capable of establishing antitrust impact on a
class-wide basis. Because antitrust impact—i.e., that the
Tuna Suppliers’ collusion had a common, supra-competitive
impact on a class-wide basis—is sufficient to show an injury-
in-fact traceable to the defendants and redressable by a
favorable ruling, the Tuna Purchasers have adequately
demonstrated Article III standing at the class certification
stage for all class members, whether or not that was required.
See TransUnion, 141 S.Ct. at 2208 n.4.

32
The Supreme Court expressly held open the question “whether
every class member must demonstrate standing before a court certifies a
class.” TransUnion, 141 S.Ct. at 2208 n.4 (emphasis omitted). Outside
the class action context, the Supreme Court has held that each plaintiff
must demonstrate Article III standing in order to seek additional money
damages and, therefore, a litigant must demonstrate Article III standing in
order to intervene as a matter of right. Town of Chester v. Laroe Ests.,
Inc., 137 S.Ct. 1645, 1651 (2017). But the Supreme Court has long
recognized that in cases seeking injunctive or declaratory relief, only one
plaintiff need demonstrate standing to satisfy Article III. See, e.g.,
Baggett v. Bullitt, 377 U.S. 360, 366 n.5 (1964); Rumsfeld v. F. for Acad.
& Institutional Rts., Inc., 547 U.S. 47, 52 n.2 (2006); Horne v. Flores,
557 U.S. 433, 446–47 (2009). We have likewise applied this rule where
a class sought injunctive or equitable relief. See Bates v. United Parcel
Serv., Inc., 511 F.3d 974, 985 (9th Cir. 2007) (en banc). We therefore
overrule the statement in Mazza that “no class may be certified that
contains members lacking Article III standing,” 666 F.3d at 594, which
does not apply when a court is certifying a class seeking injunctive or
other equitable relief. We do not overrule Mazza as to any other holding
which remain good law.
58 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

Accordingly, we affirm the district court’s certification of
the DPP class.

V

We next turn to the Tuna Suppliers’ arguments that the
district court abused its discretion in determining that the
evidence presented by the CFPs and EPPs was capable of
proving the element of antitrust impact under California’s
Cartwright Act, thus satisfying the prerequisites of Rule
23(b)(3).

A

The CFP subclass includes individuals and commercial
entities who purchased bulk sized packaged tuna (packages
of 40 ounces or more) from six companies (direct purchasers)
which had purchased the tuna from the Tuna Suppliers. The
CFPs’ theory of antitrust impact proceeds in two steps. First,
the CFPs claim that the Tuna Suppliers’ conspiracy resulted
in the direct purchasers paying an overcharge. Second, the
CFPs claim that the overcharge was passed on from the direct
purchasers to the CFPs.

The CFPs supported this theory with the expert testimony
and report of economist Dr. Michael Williams, who
employed a methodology substantially similar to that
employed by Dr. Mangum. Dr. Williams first conducted a
regression analysis to determine the overcharge the CFPs’
suppliers (i.e., the six direct purchasers) incurred because of
the Tuna Suppliers’ collusion. Like Dr. Mangum’s analysis,
Dr. Williams’s regression analysis controlled for the effect of
other variables that affected price in order to isolate the effect
of the Tuna Suppliers’ collusion. Dr. Williams concluded
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 59

that COSI overcharged the CFPs’ direct purchasers by
16.6 percent, StarKist by 18.2 percent, and Bumble Bee by
15.3 percent.

Next, Dr. Williams performed a separate regression
analysis to determine if those overcharges passed through to
the CFPs, and determined that the direct purchasers passed
through 92 to 113 percent of their overcharge to the CFPs.
Dr. Williams then performed two tests to verify that his
estimates applied class-wide, both of which confirmed his
theory.

To rebut Dr. Williams’s analysis, the Tuna Suppliers
relied on a critique by economist Dr. Linda Haider.
Dr. Haider asserted that Dr. Williams erroneously assumed
that all CFPs paid a common overcharge and that the same
overcharge was passed through to the individual CFPs.
Dr. Haider also contended that some of the CFP class
members, such as food preparers and distributors, were not
impacted because they could have passed through their
overcharges to other purchasers downstream. Finally,
Dr. Haider claimed that Dr. Williams’s model was unreliable
because it failed to account for non-defendant tuna purchased
by the CFPs’ direct purchasers.

The district court reviewed Dr. Williams’s report and
testimony as well as Dr. Haider’s critiques, and after
resolving the parties’ disputes, concluded that Dr. Williams’s
methodology was valid and capable of resolving the antitrust
impact issue in a single stroke, even though the Tuna
Suppliers could raise the same critiques at trial to persuade
the jury.
60 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

On appeal, the Tuna Suppliers argue that the district court
abused its discretion in concluding that Dr. Williams’s
methodology satisfied Rule 23(b)(3)’s requirement of
common proof of antitrust impact, because Dr. Williams
erred in assuming that all direct purchasers were overcharged
by the same percentage and that each class member was
subject to the same pass-through rate. We disagree. As
explained in Section IV, supra, a district court does not abuse
its discretion in concluding that a regression model such as
the one used by Dr. Williams may be capable of showing
class-wide antitrust impact, provided that the district court
considers factors that may undercut the model’s reliability
(such as unsupported assumptions, erroneous inputs, or
nonsensical outputs such as false positives) and resolves
disputes raised by the parties. The district court did so in this
case, and therefore did not abuse its discretion in concluding
that Dr. Williams’s methodology was reliable and capable of
showing class-wide impact.

We also reject the Tuna Suppliers’ argument based on
Dr. Haider’s contention that some CFP class members may
have passed on their overcharges to downstream purchasers.
Dr. Haider claimed that the CFPs’ ability to prove common
impact was problematic because the impact of overcharges on
class members who passed on their overcharges would be
different from the impact on members who did not pass on
such overcharges. The district court did not abuse its
discretion in rejecting this argument on the ground that the
Tuna Suppliers had not shown that determining whether or
not those class members had passed overcharges down the
distribution chain would overwhelm the common issues and
require an individualized analysis. Therefore, the district
court could reasonably conclude that the common question of
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 61

antitrust impact predominated over individualized questions
concerning a passed-on overcharge.

B

The EPP subclass contains individual consumers who
purchased the Tuna Suppliers’ products for personal
consumption. Thus, like the CFPs, the EPPs are indirect
purchasers whose theory of antitrust impact depends on two
separate overcharges: first, an overcharge by the Tuna
Suppliers to the direct purchasers (i.e., retail stores), and then
an overcharge passed on to the EPPs. To carry their burden
of showing they could establish class-wide overcharges
through common proof, the EPPs offered the testimony of
economist Dr. David Sunding, who employed a methodology
substantially similar to that employed by Dr. Mangum and
Dr. Williams.

Like Drs. Mangum and Williams, Dr. Sunding first
conducted a regression analysis to isolate the impact of the
collusion on the direct purchasers, which he concluded was
an 8.1 percent overcharge from COSI, 4.5 percent from
StarKist, and 9.4 percent from Bumble Bee. He then
determined that the overcharges passed through to the EPP
class members ranged from 65.3 to 135 percent with an
estimated pass-through rate of 100 percent for the entire
class. Dr. Sunding provided qualitative, quantitative and
anecdotal evidence to support his assumption of a pass
through rate for the entire class, including an examination of
retail scanner data and the Tuna Suppliers’ internal records.

Dr. Haider critiqued Dr. Sunding’s methodology and
findings on many of the same grounds as she criticized
Dr. Williams’s model and conclusions. She also made the
62 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

additional criticisms that Dr. Sunding’s methodology
produced absurd results because it showed prices that made
no economic sense, and that his model ignored, and therefore
failed to control for, important factors like loss-leader and
focal point pricing. The district court analyzed the evidence
and the experts’ disputes, and concluded that Dr. Sunding’s
report and testimony were capable of showing antitrust
impact common to the class, for the same reasons explained
in the court’s analysis of Dr. Mangum’s and Dr. Williams’s
models. The district court determined that Dr. Haider’s
additional critiques were based either on a misreading of
Dr. Sunding’s report, or her own miscalculations.

On appeal, the Tuna Suppliers argue only that
Dr. Sunding’s model and testimony was not capable of
proving common impact for all class members because of its
use of “averaging assumptions.” This argument fails for the
reasons explained above. See supra Section IV.A. Thus, the
district court properly considered and rejected Dr. Haider’s
arguments, and determined that Dr. Sunding’s methodology
was capable of proving antitrust impact on a class-wide basis.
That is enough to satisfy Rule 23(b)(3).

VI

In a complex market such as the one at issue here, where
different purchasers with different bargaining power
purchased a range of products at different prices from
different suppliers, commentators have raised reasonable
questions whether statistical models are capable of resolving
the issue of antitrust impact with common proof. See, e.g.,
Michelle M. Burtis & Darwin V. Neher, Correlation and
Regression Analysis in Antitrust Class Certification,
77 Antitrust L.J. 495, 518 (2011). But such statistical models
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 63

and other evidence have been accepted as probative in a range
of litigation contexts, and the Supreme Court has made clear
that the permissibility of statistical evidence “turns not on the
form a proceeding takes—be it a class or individual
action—but on the degree to which the evidence is reliable in
proving or disproving the elements of the relevant cause of
action.” Tyson Foods, 577 U.S. at 455. Here the district
court did not abuse its discretion in rigorously analyzing such
statistical evidence, determining that it was not flawed in a
manner that would make it incapable of providing class-wide
proof, see supra Section III.C, concluding that the evidence
was sufficient to sustain a jury verdict on the question of
antitrust impact for the entire class, and preserving the
defendants’ ability to challenge the persuasiveness of such
evidence at trial. We therefore affirm the district court’s
decision to certify the Tuna Purchasers’ three subclasses
under Rule 23(b)(3). Nevertheless, the Tuna Suppliers will
have the opportunity to convince a jury that not all class
members were overcharged due to their collusion.

AFFIRMED.

LEE, Circuit Judge, with whom KLEINFELD, Circuit Judge,
joins, dissenting:

Over the past two decades, plaintiffs have notched over
$103 billion in settlements from securities class actions
alone.1 If we include other types of class actions—wage and

1
See Securities Class Action Settlements—2019 Review and
Analysis, Harvard Law School Forum on Corporate Governance, available
at https://corpgov.law.harvard.edu/2020/03/11/securities-class-action-
64 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

hour, consumer lawsuits, antitrust disputes, and many
others—that settlement amount almost certainly swells up by
tens of billions of dollars more. These settlement sums are
staggering because class action cases rarely go to trial. If
trials these days are rare, class action trials are almost
extinct.2 And it is no wonder why class actions settle so
often: If a court certifies a class, the potential liability at trial
becomes enormous, maybe even catastrophic, forcing
companies to settle even if they have meritorious defenses.

That is why the Supreme Court has urged lower courts to
“rigorous[ly]” scrutinize whether plaintiffs have met class
certification requirements. See Wal-Mart Stores, Inc. v.
Dukes, 564 U.S. 338, 351 (2011). The majority opinion,
however, allows the district court to certify a class, even
though potentially about one out of three class members
suffered no injury. But if defendants’ econometrician expert
is correct that almost a third of the class members may not
have suffered injury, plaintiffs have not shown the
predominance of common issues under Rule 23(b).

The district court acknowledged the dueling experts’
differing opinions on this crucial question but held that it
would leave that issue for another day—at trial—because it
involves a merits issue that a jury should decide. See In re
Packaged Seafood Prods. Antitrust Litig., 332 F.R.D. 308,

settlements-2019-review-and-analysis/ (last visited Oct. 21, 2021).
2
See, e.g., Securities Class Action Filings, 2020 Year in Review,
Cornerstone Research, at 18, available at https://www.cornerstone.com/
Publications/Reports/Securities-Class-Action-Filings-2020-Year-in-
Review (last visited Oct. 21, 2021) (noting only 11 securities class action
cases tried to verdict in the past quarter century and only one tried since
2014).
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 65

325–28 (S.D. Cal. 2019). But as a practical matter, that day
will likely never come to pass because class action cases
almost always settle once a court certifies a class. A district
court thus must serve as a gatekeeper to resolve key issues
implicating Rule 23 requirements—including whether too
many putative class members suffered no injury—at the class
certification stage. See Med. & Chiropractic Clinic, Inc. v.
Oppenheim, 981 F.3d 983, 992 (11th Cir. 2020) (“Rule 23
makes clear that the district court in which a class action is
filed operates as a gatekeeper”).

Punting this key question until later amounts to handing
victory to plaintiffs because this case will likely settle without
the court ever deciding that issue. The refusal to address this
key dispute now is akin to the NFL declining to review a
critical and close call fumble during the waning minutes of
the game unless and until the game reaches overtime (which,
of course, will likely never occur if it does not decide the
disputed call). Such a practice is neither fair nor true to the
rule.

I thus respectfully dissent.

* * * * *

The U.S. Department of Justice’s investigation revealed
that the three largest domestic producers of packaged tuna
colluded to try to inflate the prices of their products. This
class action lawsuit soon followed the criminal indictment.
Among the plaintiffs include the direct purchasers of the tuna
products, ranging from multibillion dollar chain retailers to
small mom-and-pop stores. Not surprisingly, some plaintiffs
(such as Walmart) wield substantial negotiating leverage:
They can demand lower prices or extract additional
66 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

promotional credits or rebates that defray the offered price.
In contrast, an owner of a bodega likely cannot demand even
an audience with the tuna producers, let alone ask for lower
prices or more promotional credits.

Despite the varying negotiating power among the
plaintiffs, their expert, Dr. Russell Mangum III, concluded
that the tuna producers overcharged the direct purchasers by
an average of 10.28%. He also suggested that about 5.5% of
the class may not have suffered an injury because of this
price-fixing. In contrast, the defendants’ expert, Dr. John
Johnson, offered an analysis showing that potentially about
28% of the class members suffered no injury.

Faced with this gaping difference between the two
experts’ conclusions, the district court acknowledged that
Dr. Johnson’s “criticisms are serious.” In re Packaged
Seafood, 332 F.R.D. at 328. But it held that this question
should be left for trial because Dr. Mangum’s method was
reliable under Daubert and “capable of showing” class-wide
impact. Id. The majority agrees with the district court, ruling
that a class can be certified—even if potentially one out of
three members suffered no injury—because Plaintiffs’ expert
offered a method “capable” of measuring class-wide impact
and the district court can winnow out those uninjured
members later at trial. But the majority opinion conflicts with
Rule 23’s text, common sense, and precedent from other
circuits.
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 67

I. The district court did not “rigorously” scrutinize the
dueling experts’ opinions about uninjured class
members.

While around 10,000 class action lawsuits are filed
annually3, class actions are “an exception to the usual rule
that litigation is conducted by and on behalf of the individual
named parties only.” Comcast Corp. v. Behrend, 569 U.S.
27, 33 (2013) (quoting Califano v. Yamasaki, 442 U.S. 682,
700–01 (1979)). Rule 23 thus establishes stringent
requirements for certifying a class.

Among the Rule 23 requirements, the plaintiff must show
that “questions of law or fact common to class members
predominate over any questions affecting only individual
members.” Fed. R. Civ. 23(b)(3). The word “common”
means “belonging to or shared . . . by all members of a
group,” while “predominate” means “to hold advantage in
numbers or quantity.”4 Rule 23(b)(3) thus requires that
questions of law or fact be shared by all or substantially all
members of the class.

The Supreme Court has also reminded us that Rule 23
does not establish a “mere pleading standard.” Wal-Mart,
564 U.S. at 350. Rather, plaintiffs must prove by a
preponderance of the evidence that they have met the Rule 23
requirements. See id.; Maj. Op. at 22–23. Rule 23 imposes

3
Class Actions 2021, Lexology, Jonathan D. Polkes and David J.
Lender, eds., at 91 (2021).
4
“Common” and “predominance,” Merriam-Webster Dictionary,
available at www.merriam-webster.com/dictionary (last checked on Oct.
21, 2021).
68 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

a requirement on the trial court, too. A trial court can certify
a class only after engaging in a “rigorous analysis” and
determining that the plaintiff has satisfied Rule 23. Wal-
Mart, 564 U.S. at 351. And in conducting that “rigorous
analysis,” trial courts “[f]requently” must assess “the merits
of the plaintiff’s underlying claim” because the issues are
often intertwined. Id.

Rule 23’s “rigorous analysis” is different from “reliable”
or “relevant.” Ellis v. Costco Wholesale Corp., 657 F.3d 970,
982–84 (9th Cir. 2011). A trial court must do more than just
consider one side’s expert opinion as “reliable” and then kick
the can down the road until trial. Rather, it must dig into the
weeds and decide the battle of dueling experts if their dispute
implicates Rule 23 requirements.

Here, the two experts’ contentions centered on
Rule 23(b)(3)’s predominance requirement—whether it has
been met if the defendants’ expert concludes that potentially
a significant number of putative class members were
uninjured. Plaintiffs’ expert argued that only about one out
of twenty class members likely did not suffer an injury, while
defendants’ expert maintained it was potentially more than
one out of four. The district court held that the plaintiffs’
expert’s opinion passed muster under Daubert but admitted
that the defendants’ expert offered “serious” criticism, too.
The district court admirably analyzed this difficult issue but
ultimately did not resolve it, ruling that a jury should decide
it at trial.

Despite the detailed analysis of the district court, I believe
it abused its discretion in committing the same error that we
cautioned against in Costco. There, the two dueling experts
offered contrasting opinions on whether Costco’s alleged
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 69

discrimination was regional or nationwide, which touched
upon Rule 23(a)’s commonality requirement (i.e., whether all
the putative class members nationwide suffered
discrimination). The trial court held the plaintiffs’ expert was
reliable under Daubert, and declined to decide which experts’
opinion should prevail at the class certification stage. It then
certified a class and ruled that this “battle of the experts”
issue could be decided at trial because Costco’s criticisms of
the expert report “attack the weight of the evidence and not
its admissibility.” Id. at 982 (quoting district court opinion).

But because that dispute implicated Rule 23(a)’s
commonality requirement, we reversed the district court’s
certification order and directed it to address it at the class
certification stage. As we put it, the trial court “confused” the
Daubert standard’s “reliable” requirement with the “rigorous
analysis” standard for Rule 23. Id. at 982 (“Instead of
judging the persuasiveness of the evidence presented, the
district court seemed to end its analysis of the plaintiffs'
evidence after determining such evidence was merely
admissible.”). Rather than “examining the merits [of the
dispute between experts] to decide this issue,” the trial court
“merely concluded that, because both Plaintiffs’ and Costco’s
evidence was admissible, a finding of commonality was
appropriate.” Id. at 984. That was error.

And that is exactly what happened here. The district
court found plaintiffs’ expert to be reliable under Daubert,
but it also conceded that the defendants’ expert offered a
“serious” critique of plaintiffs’ expert opinion. The district
court ultimately held that resolving this “battle of the experts”
was a merits issue. But the dispute over the number of
uninjured class members overlaps with Rule 23(b)(3)’s
predominance requirement as well as Rule 23(a)’s lower
70 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

threshold commonality requirement. Simply put, a plaintiff
cannot prove that common issues predominate if one out of
three putative class members suffered no harm. Cf. Mazza v.
Am. Honda Motor Co., Inc., 666 F.3d 581, 596 (9th Cir.
2012) (“[T]he relevant class must be defined in such a way as
to include only members who were [harmed by being]
exposed to advertising that is alleged to be materially
misleading.”). If a large number of class members “in fact
suffered no injury,” identifying those class members “will
predominate.” In re Asacol Antitrust Litig., 907 F.3d 42,
53–54 (1st Cir. 2018). Thus, the district court had to
“examin[e] the merits” of this dispute between the experts,
and not “merely conclude[] that” both expert reports are
reliable and admissible. Costco, 657 F.3d at 984.

The majority holds that Dr. Mangum’s estimate of a
10.2% “average” price inflation meets Rule 23’s requirements
because it shows a method “capable” of showing common
antitrust impact. The majority appears to distinguish between
(i) cases in which the class members “logically” could not
have been harmed (because, for example, they were never
exposed to the misleading advertisement) or there is
insufficient evidence to support commonality, and (ii) cases
like this one in which an expert holds that many class
members in reality may not have suffered any harm, even if
they theoretically could have. Maj. Op. 26, n.9. In the
former scenario, the majority says that a class cannot be
certified because logically there cannot be commonality
under Rule 23; in the latter case, the majority appears to argue
that it is a merits issue because a jury will need to assess the
persuasiveness of the expert’s opinion.

I believe that creates a false distinction. Nothing in our
decision in Costco or the Supreme Court’s opinion in
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 71

Wal-mart creates such a difference. If the evidence presented
implicates Rule 23—as it does here—then the district court
must decide whether the plaintiffs have “prove[n] that there
are in fact . . . common questions of law or fact,” even if it
means assessing the persuasiveness of the expert opinions.
Wal-mart, 564 U.S. at 350–51 (emphasis in original). In
Costco, we chastised the district court for not “judging the
persuasiveness of the evidence presented” and “end[ing] its
analysis of the plaintiffs' evidence after determining such
evidence was merely admissible.” 657 F.3d at 982. If we
had to refrain from deciding the persuasiveness of an expert
opinion used to show commonality, a plaintiff could prevail
on class certification by merely offering a well-written and
plausible expert opinion. See West v. Prudential Sec., Inc.,
282 F.3d 935, 938 (7th Cir. 2002) (failure to resolve dueling
experts “amounts to a delegation of judicial power to the
plaintiffs, who can obtain class certification just by hiring a
competent expert”).

Admittedly, resolving a battle of dueling experts over
highly technical issues may seem like a difficult job for a
court. But that tough task is likely even more difficult and
daunting for jurors. In the end, a “district judge may not duck
hard questions by observing that each side has some support
. . . Tough questions must be faced and squarely decided, if
necessary by holding evidentiary hearings and choosing
between competing perspectives.” Id. After reviewing the
evidence, a district court must make findings of fact
necessary for determining whether Rule 23’s requirements
have been met.

And here, the expert opinion offered by Plaintiffs to show
commonality (though admissible) is not persuasive. The
majority contends that the expert’s model is capable of
72 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

measuring class-wide impact through an “averaging
assumption” of 10.2% price inflation from the price-fixing
conspiracy. Put another way, the model assumes that almost
all class members suffered an injury because the price-fixing
would elevate the list price of tuna for everyone, even if
individual class members ultimately paid different prices for
the tuna. But the expert’s assumption flies against common
sense and empirical evidence. Powerful retailers (like
Walmart) are not passive or ill-informed consumers; they will
not sit still when faced with a price increase. They will
fiercely negotiate the list price down, or more likely, demand
promotional credits or rebates that offset any price increase.
See R. Pandey, et al., Factors Influencing Organization
Success: A Case Study of Walmart, International Journal of
Tourism & Hospitality in Asia Pasific, Vol. 4, No. 2, June
2021. See also Gary Rivlin, Rigged: Supermarket Shelves for
Sale, Center for Science in the Public Interest, September
2016, available at cspinet.org/Rigged (last visited January 4,
2021).

Major retailers wield significant power over
manufacturing and food companies because they represent
the major channel to distribute the food products. If a major
retail chain refuses to carry a company’s product after a
pricing dispute, it can significantly affect that company’s
bottom line. As one case study put it, “Walmart has huge
bargaining power since . . . it is one of the largest distributors
for manufacturing [sic]. For instance, 17% of the total sales
of P&G and 38.7% of the total sales of CCA Industries rely
on Walmart stores. Without Walmart, these businesses would
be unable to operate.” Pandey, supra page 10, at 120.

Large retailers can also extract rebate or promotional
concessions from the companies by threatening to place their
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 73

products at the bottom of the shelves or less-visited aisles
where consumers are less likely to notice them. All told,
large retailers use this power to “collect more than $50 billion
a year in trade fees and discounts from food and beverage
companies.” Rivlin, supra page 10, at ii. And “[f]ood
manufacturers pay these fees . . . because they have no
choice. The stores are the gatekeepers.” Id. at 21.

None of this is to say that Wal-Mart and other retailers
achieved those price discounts and promotional credits or
rebates here. We simply do not know because Plaintiffs’
expert did not adequately consider it.5 The only way we can
find out if Wal-Mart and other major retailers suffered any
injury (and if so, how much) would be if we conducted highly
individualized analyses of each class member. But that
would defeat the commonality requirement under Rule 23.

The majority seemingly waves away this difference in
negotiating power between the class members by relying on
our oft-quoted language that the “need for individualized
findings as to amount of damages does not defeat class
certification.” Maj. Op. 30 (citing Vaquero v. Ashley
Furniture Indus., Inc., 824 F.3d 1150, 1155 (9th Cir. 2016);
Pulaski & Middleman, LLC v. Google, Inc., 802 F.3d 979,
988 (9th Cir. 2015)).

5
The majority cites the deposition testimony of Plaintiffs’ expert to
argue that he considered promotional credits and rebates. Maj. Op. 36,
n.16. But the expert added the caveat that he did so only in instances that
he “could reliably” calculate the data. He then conceded that he did not
include “discount or promotional information” with much of the data but
said that “I have done all that I could.” He ultimately concluded that he
could measure damages by relying on the average 10.2% “overcharge”
analysis in his expert report.
74 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

I believe our court has misconstrued that often-quoted
language to create a sweeping rule that gives a free pass to the
intractable problem of highly individualized damages
analyses. And such a rule also conflicts with the Supreme
Court’s holding that a class action must be capable of being
resolved in “one stroke.” Wal-mart, 564 U.S. at 350; see
also Comcast, 569 U.S. at 35 (requiring a “rigorous analysis”
to confirm that the damages model is “consistent with its
liability case”).

We first stated that the “amount of damages is invariably
an individual question and does not defeat class action
treatment” in Blackie v. Barrack, 524 F.2d 891, 905 (9th Cir.
1975). That was a securities fraud class action, and we
recognized that “computing individual damages will be
virtually a mechanical task” because “the amount of price
inflation during the period can be charted.” Id. (emphasis
added). Put another way, damages can be easily calculated
because it is a plug-and-play exercise: Look at the number of
shares bought by each shareholder and the price of the share
that day, and compare it to the price inflation caused by the
misrepresentation. While each class member may have
individualized damages, the damages can be easily calculated
for the entire class in “one stroke.” See Wal-mart, 564 U.S.
at 350.

Since Barrack, we have applied that concept mostly in
employment and wage-and-hour cases. See, e.g., Vaquero,
824 F.3d at 1152 (suing for payment for unpaid hours on non-
sales work); Levya v. Medline Indus. Inc., 716 F.3d 510, 514
(9th Cir. 2013) (class action based on wage and hour claims
in which defendant’s “computerized payroll and time-keeping
database would enable the court to accurately calculate
damages”). Wage-and-hour cases present another mechanical
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 75

application scenario: a class administrator can easily look at
the employer’s payroll records and calculate the number of
hours or wages that each employee was underpaid. At times,
however, we have quoted that language without determining
whether damages could be calculated mechanically or if the
court would have to engage in individualized mini-trials for
damages. See, e.g., Yokoyama v. Midland Nat. Life Ins. Co.,
594 F.3d 1087, 1094 (9th Cir. 2010) (stating that
individualized damages do not defeat class certification in
case involving misleading statements in annuities
promotional materials).

But here, it will not be a “mechanical task” to calculate
the damages for each class member. Blackie, 524 F.2d
at 905. The district court will need to conduct individualized
mini-trials to determine whether each class member suffered
an injury, and if so, what the damages are for each member.
That would upend Rule 23’s commonality requirement. The
majority opinion notes that commonality may still be met,
even if a defendant “might attempt to pick off the occasional
class member here or there.” Maj. Op. 56, n. 31 (citing
Halliburton Co. v. Erica P. John Fund, Inc., 573 U.S. 258,
276 (2014)). But our case does not involve a “pick off” of a
few uninjured class members, but rather a massive grab bag
of class members—perhaps almost a third of the class—who
may not have suffered any harm. The district court thus will
have to engage in individualized mini-trials to figure out who
suffered an injury.

Finally, the majority suggests that an oversized class with
unharmed class members does not pose a practical problem
if a method can separate the uninjured from the injured at
trial. No harm, no foul, the majority implies. But that cannot
be so if a large number of class members (certainly, a third)
76 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

suffered no injuries. Suppose that 80% of the putative class
members suffered no harm. Could a district court still certify
a class just because it could later winnow out the 80% who
were uninjured? Would Rule 23(b)’s predominance of
common issues be met even if only 20% of the putative
members belong in the class? By definition, a class with 80%
uninjured members cannot present a predominance of
common issues because they have nothing in common with
the remaining sliver of injured members.

If we allow a court to certify a class in which a large
number of putative class members have suffered no injury,
we will allow plaintiffs to weaponize Rule 23 to impose an in
terrorem effect on defendants. The “[c]ertification of the
class is often, if not usually, the prelude to a substantial
settlement by the defendant because the costs and risks of
litigating further are so high.” Amgen Inc. v. Conn. Ret. Plans
& Tr. Funds, 568 U.S. 455, 485 (2013) (Scalia, J.,
dissenting). Indeed, “when damages allegedly owed to tens
of thousands of potential claimants are aggregated and
decided at once, the risk of an error will often become
unacceptable. Faced with even a small chance of devastating
loss, defendants will be pressured into settling questionable
claims.” AT&T Mobility LLC v. Concepcion, 563 U.S. 333,
350 (2011).

So if a court certifies a class with many uninjured class
members, it dramatically expands the potential exposure and
artificially jacks up the stakes. It matters little that the
uninjured class members can be separated at trial because
with “the stakes so large . . . settlement becomes almost
inevitable—and at a price that reflects the risk of a
catastrophic judgment as much as, if not more than, the actual
merit of the claims.” In re Bridgestone/Firestone, Inc.,
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 77

288 F.3d 1012, 1016 (7th Cir. 2002). The opportunity at trial
to jettison uninjured members from the certified class is a
phantom solution because defendants will have little choice
but to settle before then.

II. The majority’s rejection of a de minimis rule creates
a circuit split.

I believe the majority also errs in rejecting a de minimis
rule. To be sure, a plaintiff need not show that every single
putative class member has suffered an injury. But the number
of uninjured class members should be de minimis—based on
Rule 23’s language, common sense, and precedent from other
circuits.

First, as noted above, the words “common” and
“predominate” in Rule 23(b)(3) suggest that the class should
include only (or mostly only) people who have suffered an
injury. If one-third—or half or two-thirds—of the class
members suffered no injury, it follows that “common” issues
would not “predominate,” as required under the text of Rule
23, because those uninjured class members have little in
common with those who have been harmed. In short, Rule 23
allows a de minimis number of uninjured members but no
more.

Second, allowing more than a de minimis number of
uninjured class members tilts the playing field in favor of
plaintiffs. By expressly rejecting a de minimis rule, the
majority’s opinion will invite plaintiffs to concoct oversized
classes stuffed with uninjured class members—with little fear
of having their class certification bids being denied for lack
of “predominance” or “commonality.” And in creating these
grossly oversized classes, plaintiffs will inflate the potential
78 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS

liability (and ratchet up the attorney’s fees based in part on
that amount) to extract a settlement, even if the merits of their
claims are questionable.

Finally, the majority opinion needlessly creates a split
with other circuits that have endorsed a de minimis rule. The
D.C. Circuit, for example, suggested that “5% to 6%
constitutes the outer limits of a de minimis number.” In re
Rail Freight Fuel Surcharge Antitrust Litig., 934 F.3d 619,
624–25 (D.C. Cir. 2019) (cleaned up). The district court had
found that the class of 16,065 members (12.7% of whom
were uninjured) failed to meet the predominance requirement
because more than a “de minimis” number were uninjured.
Id. at 623–24. The D.C. Circuit on appeal affirmed, ruling
that the plaintiffs’ model “even if sufficiently reliable, does
not prove classwide injury.” Id. at 623. Put another way,
“even assuming the model can reliably show injury and
causation for 87.3 percent of the class, that still leaves the
plaintiffs with no common proof of those essential elements
of liability for the remaining 12.7 percent.” Id. at 623–24

Likewise, the First Circuit suggested that “around 10%”
of uninjured class members marks the de minimis border. See
In re Asacol, 907 F.3d at 47, 51–58. The First Circuit was
perhaps willing to look past “a very small absolute number of
class members” who have suffered no injury because they
“might be picked off in a manageable, individualized process
at or before trial.” Id. at 53. But if “there are apparently
thousands who in fact suffered no injury . . . [t]he need to
identify those individuals will predominate.” Id. at 53–54.

* * * * *
 OLEAN WHOLESALE GROCERY V. BUMBLE BEE FOODS 79

While this case centers on the narrow issue of price-fixing
of canned tuna, its implications extend beyond to a wide sea
of class action cases. I fear that today’s decision will unleash
a tidal wave of monstrously oversized classes designed to
pressure and extract settlements.

I respectfully dissent.