Department of Revenue of Kentucky v. Davis

(Slip Opinion) OCTOBER TERM, 2007 1

Syllabus

NOTE: Where it is feasible, a syllabus (headnote) will be released, as is
being done in connection with this case, at the time the opinion is issued.
The syllabus constitutes no part of the opinion of the Court but has been
prepared by the Reporter of Decisions for the convenience of the reader.
See United States v. Detroit Timber & Lumber Co., 200 U. S. 321, 337.

SUPREME COURT OF THE UNITED STATES

Syllabus

DEPARTMENT OF REVENUE OF KENTUCKY ET AL. v.
DAVIS ET UX.

CERTIORARI TO THE COURT OF APPEALS OF KENTUCKY

No. 06–666. Argued November 5, 2007—Decided May 19, 2008
Kentucky exempts from state income taxes interest on bonds issued by
it or its political subdivisions but not on bonds issued by other States
and their subdivisions. After paying state income tax on out-of-state
municipal bonds, respondents sued petitioners (hereinafter Ken-
tucky) for a refund, claiming that Kentucky’s differential tax imper-
missibly discriminated against interstate commerce. The trial court
ruled for Kentucky, relying in part on a “market-participation” excep-
tion to the dormant Commerce Clause limit on state regulation. The
State Court of Appeals reversed, finding that Kentucky’s scheme ran
afoul of the Commerce Clause.
Held: The judgment is reversed, and the case is remanded.
197 S. W. 3d 557, reversed and remanded.
JUSTICE SOUTER delivered the opinion of the Court, except as to
Part III–B, concluding that Kentucky’s differential tax scheme does
not offend the Commerce Clause. Pp. 7–13, 20–28.
(a) Modern dormant Commerce Clause law is driven by concern
about “economic protectionism—that is, regulatory measures de-
signed to benefit in-state economic interests by burdening out-of-
state competitors,” New Energy Co. of Ind. v. Limbach, 486 U. S. 269,
273–274—but that concern is limited by federalism favoring a degree
of local autonomy. Under the resulting analysis, a discriminatory
law is “virtually per se invalid.” Oregon Waste Systems, Inc. v. De-
partment of Environmental Quality of Ore., 511 U. S. 93, 99. An ex-
ception covers States that go beyond regulation and themselves “par-
ticipat[e] in the market” to “exercis[e] the right to favor [their] own
citizens over others,” Hughes v. Alexandria Scrap Corp., 426 U. S.
794, 810, reflecting a “basic distinction . . . between States as market
2 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Syllabus

participants and States as market regulators,” Reeves, Inc. v. Stake,
447 U. S. 429, 436. Last Term, in a case decided independently of the
market participant exception, this Court upheld an ordinance requir-
ing trash haulers to deliver solid waste to a public authority’s proc-
essing plant, finding that it addressed what was “ ‘both typically and
traditionally a local government function,’ ” and did “not discriminate
against interstate commerce for purposes of the dormant Commerce
Clause,” United Haulers Assn., Inc. v. Oneida-Herkimer Solid Waste
Management Authority, 550 U. S. ___, ___. Pp. 7–10.
(b) United Haulers provides a firm basis for reversal here. The
logic that a government function is not susceptible to standard dor-
mant Commerce Clause scrutiny because it is likely motivated by le-
gitimate objectives distinct from simple economic protectionism ap-
plies with even greater force to laws favoring a State’s municipal
bonds, since issuing debt securities to pay for public projects is a
quintessentially public function, with a venerable history. Bond pro-
ceeds are a way to shoulder the cardinal civic responsibilities listed in
United Haulers: protecting citizens’ health, safety, and welfare. And
United Haulers’ apprehension about “unprecedented . . . interference”
with a traditional government function is warranted here, where re-
spondents would have this Court invalidate a century-old taxing
practice presently employed by 41 States and supported by all. In
fact, emphasizing an enterprise’s public character is just one step in
addressing the fundamental element of dormant Commerce Clause
jurisprudence that “any notion of discrimination assumes a compari-
son of substantially similar entities,” id., at ___. Viewed through the
lens of Bonaparte v. Tax Court, 104 U. S. 592, there is no forbidden
discrimination because Kentucky, as a public entity, does not have to
treat itself as being “substantially similar” to other bond issuers in
the market. Pp. 11–13.
(c) A look at the specific markets in which the exemption’s effects
are felt confirms that no traditionally forbidden discrimination is un-
derway and points to the tax policy’s distinctive character. In both
the interstate market as most broadly conceived—issuers and holders
of all fixed-income securities—and the more specialized market—
commerce solely in federally tax-exempt municipal bonds, often con-
ducted through interstate municipal bond funds—nearly every taxing
State believes its public interests are served by the same tax-and-
exemption feature which is supported in this Court by every State.
These facts suggest that no State perceives any local advantage or
disadvantage beyond the permissible ones open to a government and
to those who deal with that government when it enters the market.
An equally significant perception emerges from examining the mar-
ket for municipal bonds within the issuing State, a large proportion
 Cite as: 553 U. S. ____ (2008) 3

Syllabus

of which market is managed by one or more single-state funds. An
important feature of such markets is that intrastate funds absorb se-
curities issued by smaller or lesser known municipalities that inter-
state markets tend to ignore. Many single-state funds would likely
disappear if the current differential tax schemes were upset, and
there is no suggestion that the interstate markets would welcome the
weaker municipal issues that would lose their local market homes af-
ter a Davis victory. Financing for long-term municipal improvements
would thus change radically if the differential tax feature disap-
peared. The fact that the differential tax scheme is critical to the op-
eration of an identifiable segment of the current municipal financial
market demonstrates that the States’ unanimous desire to preserve
the scheme is a far cry from the private protectionism that has driven
the dormant Commerce Clause’s development. Pp. 20–23.
(e) The Court generally applies the rule in Pike v. Bruce Church,
Inc., 397 U. S. 137, 142, that even nondiscriminatory burdens on
commerce may be struck down on a showing that they clearly out-
weigh the benefits of a state or local practice. But the current record
and scholarly material show that the Judicial Branch is not institu-
tionally suited to draw reliable conclusions of the kind that would be
necessary for the Davises to satisfy a Pike burden in this particular
case. Pp. 23–27.

SOUTER, J., announced the judgment of the Court and delivered the
opinion of the Court, except as to Part III–B. STEVENS and BREYER, JJ.,
joined that opinion in full; ROBERTS, C. J., and GINSBURG, J., joined all
but Part III–B; and SCALIA, J., joined all but Parts III–B and IV. STE-
VENS, J., filed a concurring opinion. ROBERTS, C. J., and SCALIA, J., filed
opinions concurring in part. THOMAS, J., filed an opinion concurring in
the judgment. KENNEDY, J., filed a dissenting opinion, in which ALITO,
J., joined. ALITO, J., filed a dissenting opinion.
 Cite as: 553 U. S. ____ (2008) 1

Opinion of the Court

NOTICE: This opinion is subject to formal revision before publication in the
preliminary print of the United States Reports. Readers are requested to
notify the Reporter of Decisions, Supreme Court of the United States, Wash­
ington, D. C. 20543, of any typographical or other formal errors, in order
that corrections may be made before the preliminary print goes to press.

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

JUSTICE SOUTER delivered the opinion of the Court,
except as to Part III–B.*
For the better part of two centuries States and their
political subdivisions have issued bonds for public pur­
poses, and for nearly half that time some States have
exempted interest on their own bonds from their state
income taxes, which are imposed on bond interest from
other States. The question here is whether Kentucky’s
version of this differential tax scheme offends the Com­
merce Clause. We hold that it does not.
I

A

Like most other States, the Commonwealth of Kentucky
taxes its residents’ income. See Ky. Rev. Stat. Ann.
§141.020(1) (West 2006). The tax is assessed on “net
income,” see ibid., calculated by reference to “gross in­
come” as defined by the Internal Revenue Code, see
§§141.010(9)–(11) (West Supp. 2007),1 which excludes
——————
* JUSTICE GINSBURG joins all but Part III–B of this opinion.
1 Specifically, Kentucky defines “net income” for noncorporate tax­
2 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

“interest on any State or local bond” (“municipal bond,” for
short2), 26 U. S. C. §103(a). Kentucky piggybacks on this
exclusion, but only up to a point: it adds “interest income
derived from obligations of sister states and political
subdivisions thereof” back into the taxable net. Ky. Rev.
Stat. Ann. §141.010(10)(c). Interest on bonds issued by
Kentucky and its political subdivisions is thus entirely
exempt,3 whereas interest on municipal bonds of other
States and their subdivisions is taxable. (Interest on
bonds issued by private entities is taxed by Kentucky
——————
payers as “adjusted gross income,” minus certain deductions. See Ky.
Rev. Stat. Ann. §141.010(11). “Adjusted gross income,” in turn, is
defined as “gross income” minus other deductions spelled out in the
Internal Revenue Code and elsewhere in the Kentucky statutes. See
§141.010(10). Finally, “gross income” has the same meaning set out in
§61 of the Internal Revenue Code. See §141.010(9); see also 26 U. S. C.
§61.
2 “Municipal bond” is commonly defined as a “debt obligation of a

state or local government entity.” J. Downes & J. Goodman, Dictionary
of Finance and Investment Terms 439 (7th ed. 2006). We use that
definition here; our references to “municipal bonds” thus include bonds
issued by States and their political subdivisions.
An argument raised by one of the Davises’ amici focuses on so-called
“private-activity,” “industrial-revenue,” or “conduit” bonds, a subset of
municipal bonds used to finance projects by private entities. These
bonds are often (but not always) exempt under the Kentucky scheme.
Amici contend that Kentucky’s exemption of these bonds, at the very
least, plainly violates the Commerce Clause. See Brief for Alan D.
Viard et al. as Amici Curiae 25–26. This argument, however, was not
considered below, was never pressed by the Davises themselves, and is
barely developed by amici. Moreover, we cannot tell with certainty
what the consequences would be of holding that Kentucky violates the
Commerce Clause by exempting such bonds; we must assume that it
could disrupt important projects that the States have deemed to have
public purposes. Accordingly, it is best to set this argument aside and
leave for another day any claim that differential treatment of interest
on private-activity bonds should be evaluated differently from the
treatment of municipal bond interest generally.
3 There are some exceptions which derive from the federal exclusion,

see 26 U. S. C. §103(b), but they do not matter here.
 Cite as: 553 U. S. ____ (2008) 3

Opinion of the Court

regardless of the private issuer’s home.)
The ostensible reason for this regime is the attractive­
ness of tax-exempt bonds at “lower rates of interest . . .
than that paid on taxable . . . bonds of comparable risk.”
M. Graetz & D. Schenk, Federal Income Taxation 215 (5th
ed. 2005) (hereinafter Graetz & Schenk). Under the In­
ternal Revenue Code, for example, see 26 U. S. C. §103, “if
the market rate of interest is 10 percent on a comparable
corporate bond, a municipality could pay only 6.5 percent
on its debt and a purchaser in a 35 percent marginal tax
bracket would be indifferent between the municipal and
the corporate bond, since the after-tax interest rate on the
corporate bond is 6.5 percent,” Graetz & Schenk 215.4 The
differential tax scheme in Kentucky works the same way;
the Commonwealth’s tax benefit to residents who buy its
bonds makes lower interest rates acceptable,5 while limit­
ing the exception to Kentucky bonds raises in-state de­
mand for them without also subsidizing other issuers.
The significance of the scheme is immense. Between
1996 and 2002, Kentucky and its subdivisions issued $7.7
billion in long-term bonds to pay for spending on transpor­
tation, public safety, education, utilities, and environ­
mental protection, among other things. IRS, Statistics of
——————
4 The amount of this benefit to municipal issuers can be approxi­
mated by comparing the interest rates on municipal bonds to those on
Treasury bonds, which are also exempt from state taxation but are
subject to federal taxation. “[A]t the end of 2006, the borrowing costs
on AAA-rated, 10-year municipal bonds on average were 80.3 percent of
comparable, but federally taxable, U. S. Treasury securities, [and] at
the end of 2005 the borrowing costs on such municipal bonds were 88.4
percent of comparable U. S. Treasury bonds.” Brief for National Fed­
eration of Municipal Analysts as Amicus Curiae 8, n. 4.
5 The precise reduction in interest rates depends on the federal and

state income tax rates, the credit rating of the issuer, the term of the
bond, and market factors. See id., at 8. The reduction in interest rates
is generally greater the higher are a State’s income tax rates. See id.,
at 9, and n. 6.
4 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

Income Bulletin, C. Belmonte, Tax-Exempt Bonds, 1996–
2002, pp. 169–170, http://www.irs.gov/pub/irs-soi/02gov
bnd.pdf (as visited Jan. 23, 2008, and available in Clerk of
Court’s case file). Across the Nation during the same
period, States issued over $750 billion in long-term bonds,
with nearly a third of the money going to education, fol­
lowed by transportation (13%) and utilities (11%). See
ibid. Municipal bonds currently finance roughly two-
thirds of capital expenditures by state and local govern­
ments. L. Thomas, Money, Banking and Financial Mar­
kets 55 (2006).
Funding the work of government this way follows a
tradition going back as far as the 17th century. See C.
Johnson & M. Rubin, The Municipal Bond Market: Struc­
ture and Changes, in Handbook of Public Finance 483, 485
(F. Thompson & M. Green eds. 1998) (“[In] 1690 . . . Mas­
sachusetts issued bills of credit to pay soldiers who had
participated in an unsuccessful raid on the City of Que­
bec”). Municipal bonds first appeared in the United States
in the early 19th century: “New York City began to float
[debt] securities in about 1812,” A. Hillhouse, Municipal
Bonds: A Century of Experience 31 (1936) (hereinafter
Hillhouse), and by 1822 Boston “had a bonded debt of
$100,000,” id., at 32. The municipal bond market had
swelled by the mid-1840s, when the aggregate debt of
American cities exceeded $27 million, and the total debt of
the States was nearly 10 times that amount. See ibid.
Bonds funded some of the great public works of the day,
including New York City’s first water system, see id., at
31, and the Erie Canal, see R. Amdursky & C. Gillette,
Municipal Debt Finance Law §1.2.1, p. 15 (1992) (herein­
after Amdursky & Gillette). At the turn of the 20th cen­
tury, the total state and municipal debt was closing in on
$2 billion, see Hillhouse 35, and by the turn of the millen­
nium, over “$1.5 trillion in municipal bonds were out­
standing,” J. Temel, The Fundamentals of Municipal
 Cite as: 553 U. S. ____ (2008) 5

Opinion of the Court

Bonds, p. ix (5th ed. 2001).
Differential tax schemes like Kentucky’s have a long
pedigree, too. State income taxation became widespread
in the early 20th century, see A. Comstock, State Taxation
of Personal Incomes 11 (1921) (reprinted 2005) (hereinaf­
ter Comstock), and along with the new tax regimes came
exemptions and deductions, see id., at 171–184, to induce
all sorts of economic behavior, including lending to state
and local governments at favorable rates of untaxed inter­
est. New York enacted the first of these statutes in 1919,
see 1919 N. Y. Laws pp. 1641–1642, the same year it
imposed an income tax, see Comstock 104,6 and other
States followed, see, e.g., 1921 N. C. Sess. Laws p. 208;
1923 N. H. Laws p. 78; 1926 Va. Acts ch. 576, pp. 960–961,
with Kentucky joining the pack in 1936, see 1936 Ky. Acts
p. 71. Today, 41 States have laws like the one before us.7
——————
6 The Federal Government got in the game even earlier. Municipal

bonds were exempted from “every federal income tax act enacted since
passage of the Sixteenth Amendment” in 1913. Amdursky & Gillette
§7.2.1, at 440.
7 This figure includes Kentucky and 36 other States that have

schemes that are nearly identical to Kentucky’s. See Ala. Code §§40–
18–4, 40–18–14(3)(f) (2003); Ariz. Rev. Stat. Ann. §43–1021(3) (West
Supp. 2007); Ark. Code Ann. §26–51–404(b)(5) (Supp. 2007); Cal. Rev.
& Tax. Code Ann. §17133 (West 2004); Colo. Rev. Stat. Ann. §39–22–
104(3)(b) (2007); Conn. Gen. Stat. §12–701(a)(20)(A)(i) (2007); Del. Code
Ann., Tit. 30, §1106(a)(1) (1997); Ga. Code Ann. §48–7–27(b)(1)(A)
(2005); Haw. Rev. Stat. §§39–11, 47–13 (1994), 235–7(a)(6), (b)(2)
(2001); Idaho Code §§63–3022M(1), (3)(b) (Lexis 2007); Kan. Stat. Ann.
§79–32,117(b)(i) (2006 Cum. Supp.); La. Stat. Ann. §§47:48,
47:293(9)(a), (b) (West 2001 and Supp. 2008); Me. Rev. Stat. Ann., Tit.
36, §5122(1)(A) (Supp. 2007); Md. Tax-Gen. Code Ann. §10–204(b)
(Lexis Supp. 2007); Mass. Gen. Laws, ch. 62, §2(a)(1)(A) (West 2006);
Mich. Comp. Laws Ann. §206.30(1)(a) (West Supp. 2007); Minn. Stat.
§290.01, subd. 19a(1)(i) (2006); Miss. Code Ann. §27–7–15(4)(d) (Supp.
2007); Mo. Rev. Stat. §143.121(2)(b) (2007 Supp.); Mont. Code Ann.
§15–30–111(2)(a)(i) (2007); Neb. Rev. Stat. §77–2716(1)(c) (2007 Supp.);
N. H. Rev. Stat. Ann. §77:4(I) (Supp. 2007); N. J. Stat. Ann. §54A:6–14
(West 2002); N. M. Stat. Ann. §§7–2–2(B)(3), (V) (2005); N. Y. Tax Law
6 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

B

Petitioners (for brevity, Kentucky or the Common­
wealth) collect the Kentucky income tax. Respondents
George and Catherine Davis are Kentucky residents who
paid state income tax on interest from out-of-state munici­
pal bonds, and then sued the tax collectors in state court
on a refund claim that Kentucky’s differential taxation of
municipal bond income impermissibly discriminates
against interstate commerce in violation of the Commerce
Clause of the National Constitution. The trial court
granted judgment to the Commonwealth, relying in part
on our cases recognizing the “market-participant” excep­
tion to the dormant Commerce Clause limit on state regu­
lation. See App. to Pet. for Cert. A18–A19 (citing Reeves,
Inc. v. Stake, 447 U. S. 429 (1980), and Hughes v. Alexan­
dria Scrap Corp., 426 U. S. 794 (1976)).
The Court of Appeals of Kentucky reversed. See 197
S. W. 3d 557 (2006). In a brief discussion, it rejected the
reasoning of an Ohio case upholding a similar tax scheme
challenged under the Commerce Clause, see id., at 563
——————
Ann. §612(b)(1) (West 2006); N. C. Gen. Stat. Ann. §§105–134.6(b)(1)(b),
(c)(1) (Lexis 2005); N. D. Cent. Code Ann. §57–38–01.2(1)(g) (Lexis
Supp. 2007); Ohio Rev. Code Ann. §5747.01(A)(1) (Lexis Supp. 2007);
Ore. Rev. Stat. §316.680(2)(a) (2003); Pa. Stat. Ann., Tit. 72, §9901
(Purdon 2000); R. I. Gen. Laws §44–30–12(b)(1) (Supp. 2007); S. C.
Code Ann. §12–6–1120(1) (2000); Tenn. Code Ann. §67–2–104(e)(1)
(2006); Vt. Stat. Ann., Tit. 32, §5811(18)(A)(i)(II) (2007); Va. Code Ann.
§§58.1–322(B)(1), (C)(2) (Lexis Supp. 2007); W. Va. Code Ann. §§11–21–
12(b)(1), (c)(2) (Lexis Supp. 2007). It also includes four States that tax
out-of-state municipal bonds and exempt some, but not all, in-state
municipal bonds. See Iowa Code §422.7(36) (2005); Okla. Stat., Tit. 68,
§§2358.5, 2358.5A (West 2007 Supp.); Wis. Stat. §71.05(1)(c) (2003–
2004); compare Ill. Comp. Stat., ch. 35, §5/203(a)(2)(A) (West 2006) with
ch. 45, §35/80(e). Of the remaining States, Utah exempts its own
bonds, and extends reciprocal treatment to the bonds of States that do
not tax Utah bonds, see Utah Code Ann. §§59–10–114(1)(g), (6) (Lexis
2007 Supp.); Indiana exempts all municipal bonds, see Ind. Code §6–3–
1–3.5 (West 2004); and the balance have no personal income tax.
 Cite as: 553 U. S. ____ (2008) 7

Opinion of the Court

(discussing Shaper v. Tracy, 97 Ohio App. 3d 750, 647
N. E. 2d 550 (1994)), and distinguished our market par­
ticipant cases, see 197 S. W. 3d, at 564, as well as a deci­
sion from the 19th century the Commonwealth relied on,
see id., at 563–564 (discussing Bonaparte v. Tax Court,
104 U. S. 592 (1882)). The Court of Appeals thought it
had “no choice but to find that Kentucky’s system of taxing
only extraterritorial bonds runs afoul of the Commerce
Clause,” 197 S. W. 3d, at 564, and the Supreme Court of
Kentucky denied the Commonwealth’s motion for discre­
tionary review, see App. to Pet. for Cert. A14.
We granted certiorari owing to the conflict this raised on
an important question of constitutional law, and because
the result reached casts constitutional doubt on a tax
regime adopted by a majority of the States. 550 U. S. ___
(2007). We now reverse.
II
The Commerce Clause empowers Congress “[t]o regulate
Commerce . . . among the several States,” Art. I, §8, cl. 3,
and although its terms do not expressly restrain “the
several States” in any way, we have sensed a negative
implication in the provision since the early days, see, e.g.,
Cooley v. Board of Wardens of Port of Philadelphia ex rel.
Soc. for Relief of Distressed Pilots, 12 How. 299, 318–319
(1852); cf. Gibbons v. Ogden, 9 Wheat. 1, 209 (1824) (Mar­
shall, C. J.) (dictum). The modern law of what has come to
be called the dormant Commerce Clause is driven by
concern about “economic protectionism—that is, regula­
tory measures designed to benefit in-state economic inter­
ests by burdening out-of-state competitors.” New Energy
Co. of Ind. v. Limbach, 486 U. S. 269, 273–274 (1988). The
point is to “effectuat[e] the Framers’ purpose to ‘prevent a
State from retreating into [the] economic isolation,’ ” Ful­
ton Corp. v. Faulkner, 516 U. S. 325, 330 (1996) (quoting
Oklahoma Tax Comm’n v. Jefferson Lines, Inc., 514 U. S.
8 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

175, 180 (1995); brackets omitted), “that had plagued
relations among the Colonies and later among the States
under the Articles of Confederation,” Hughes v. Oklahoma,
441 U. S. 322, 325–326 (1979).
The law has had to respect a cross purpose as well, for
the Framers’ distrust of economic Balkanization was
limited by their federalism favoring a degree of local
autonomy. Compare The Federalist Nos. 7 (A. Hamilton),
11 (A. Hamilton), and 42 (J. Madison), with The Federalist
No. 51 (J. Madison); see also Garcia v. San Antonio Metro­
politan Transit Authority, 469 U. S. 528, 546 (1985) (“The
essence of our federal system is that within the realm of
authority left open to them under the Constitution, the
States must be equally free to engage in any activity that
their citizens choose for the common weal”).
Under the resulting protocol for dormant Commerce
Clause analysis, we ask whether a challenged law dis­
criminates against interstate commerce. See Oregon
Waste Systems, Inc. v. Department of Environmental Qual­
ity of Ore., 511 U. S. 93, 99 (1994). A discriminatory law is
“virtually per se invalid,” ibid.; see also Philadelphia v.
New Jersey, 437 U. S. 617, 624 (1978), and will survive
only if it “advances a legitimate local purpose that cannot
be adequately served by reasonable nondiscriminatory
alternatives,” Oregon Waste Systems, supra, at 101 (inter­
nal quotation marks omitted); see also Maine v. Taylor,
477 U. S. 131, 138 (1986). Absent discrimination for the
forbidden purpose, however, the law “will be upheld unless
the burden imposed on [interstate] commerce is clearly
excessive in relation to the putative local benefits.” Pike v.
Bruce Church, Inc., 397 U. S. 137, 142 (1970). State laws
frequently survive this Pike scrutiny, see, e.g., United
Haulers Assn., Inc. v. Oneida-Herkimer Solid Waste Man­
agement Authority, 550 U. S. ___, ___–___ (2007) (slip op.,
at 14–15) (plurality opinion); Northwest Central Pipeline
Corp. v. State Corporation Comm’n of Kan., 489 U. S. 493,
 Cite as: 553 U. S. ____ (2008) 9

Opinion of the Court

525–526 (1989); Minnesota v. Clover Leaf Creamery Co.,
449 U. S. 456, 472–474 (1981), though not always, as in
Pike itself, 397 U. S., at 146.
Some cases run a different course, however, and an
exception covers States that go beyond regulation and
themselves “participat[e] in the market” so as to “exer­
cis[e] the right to favor [their] own citizens over others.”
Alexandria Scrap, 426 U. S., at 810. This “market­
participant” exception reflects a “basic distinction . . .
between States as market participants and States as
market regulators,” Reeves, 447 U. S., at 436, “[t]here
[being] no indication of a constitutional plan to limit the
ability of the States themselves to operate freely in the
free market,” id., at 437. See also White v. Massachusetts
Council of Constr. Employers, Inc., 460 U. S. 204, 208
(1983) (“[W]hen a state or local government enters the
market as a participant it is not subject to the restraints of
the Commerce Clause”). Thus, in Alexandria Scrap, we
found that a state law authorizing state payments to
processors of automobile hulks validly burdened out-of­
state processors with more onerous documentation re­
quirements than their in-state counterparts. Likewise,
Reeves accepted South Dakota’s policy of giving in-state
customers first dibs on cement produced by a state-owned
plant, and White held that a Boston executive order re­
quiring half the workers on city-financed construction
projects to be city residents passed muster.
Our most recent look at the reach of the dormant Com­
merce Clause came just last Term, in a case decided inde­
pendently of the market participation precedents. United
Haulers, supra, upheld a “flow control” ordinance requir­
ing trash haulers to deliver solid waste to a processing
plant owned and operated by a public authority in New
York State. We found “[c]ompelling reasons” for “treating
[the ordinance] differently from laws favoring particular
private businesses over their competitors.” Id., at ___ (slip
10 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

op., at 10). State and local governments that provide
public goods and services on their own, unlike private
businesses, are “vested with the responsibility of protect­
ing the health, safety, and welfare of [their] citizens,”
ibid., and laws favoring such States and their subdivisions
may “be directed toward any number of legitimate goals
unrelated to protectionism,” id., at ___ (slip op., at 11).
That was true in United Haulers, where the ordinance
addressed waste disposal, “both typically and traditionally
a local government function.” Id., at ___ (slip op., at 12)
(quoting United Haulers Assn., Inc. v. Oneida-Herkimer
Solid Waste Management Authority, 261 F. 3d 245, 264
(CA2 2001) (Calabresi, J., concurring); internal quotation
marks omitted). And if more had been needed to show
that New York’s object was consequently different from
forbidden protectionism, we pointed out that “the most
palpable harm imposed by the ordinances—more expen­
sive trash removal—[was] likely to fall upon the very
people who voted for the laws,” rather than out-of-state
interests. United Haulers, 550 U. S., at ___ (slip op., at
13). Being concerned that a “contrary approach . . . would
lead to unprecedented and unbounded interference by the
courts with state and local government,” id., at ___ (slip
op., at 11), we held that the ordinance did “not discrimi­
nate against interstate commerce for purposes of the
dormant Commerce Clause,” id., at ___ (slip op., at 10).8
——————
8 In so holding, we distinguished our decision in C & A Carbone, Inc.
v. Clarkstown, 511 U. S. 383 (1994), which struck down a very similar
ordinance on Commerce Clause grounds. The Carbone ordinance,
however, benefited a private processing facility, and we found “this
difference constitutionally significant” for the reasons adverted to in
the main text. See United Haulers, 550 U. S., at ___ (slip op., at 1).
Although the Carbone dissent argued that the private facility was
“essentially a municipal facility,” 511 U. S., at 419 (opinion of SOUTER,
J.), United Haulers relied on the apparent view of the Carbone majority
that the facility was properly characterized as private, see 550 U. S., at
___–___ (slip op., at 7–8).
 Cite as: 553 U. S. ____ (2008) 11

Opinion of the Court

III
A
It follows a fortiori from United Haulers that Kentucky
must prevail. In United Haulers, we explained that a
government function is not susceptible to standard dor­
mant Commerce Clause scrutiny owing to its likely moti­
vation by legitimate objectives distinct from the simple
economic protectionism the Clause abhors. See id., at ___
(slip op., at 11) (“Laws favoring local government . . . may
be directed toward any number of legitimate goals unre­
lated to protectionism”); see also id., at ___ (slip op., at 12)
(noting that “[w]e should be particularly hesitant to inter­
fere . . . under the guise of the Commerce Clause” where a
local government engages in a traditional government
function).9 This logic applies with even greater force to
——————
9 JUSTICE KENNEDY’s dissent (hereinafter dissent) says this is just

circular rationalization, that the United Haulers acceptance of govern­
mental preference in support of public health, safety, and welfare is the
equivalent of justifying the law as an exercise of the “police power” and
thus an exercise in “tautology,” since almost any state law could be so
justified. See post, at 5. But this misunderstands what we said in
United Haulers. The point of asking whether the challenged govern­
mental preference operated to support a traditional public function was
not to draw fine distinctions among governmental functions, but to find
out whether the preference was for the benefit of a government fulfill­
ing governmental obligations or for the benefit of private interests,
favored because they were local. Under United Haulers, governmental
public preference is constitutionally different from commercial private
preference, and we make the governmental responsibility enquiry to
identify the beneficiary as one or the other. See supra, at 9–10; United
Haulers, supra, at ___ (slip op., at 11). Because this is the distinction at
which the enquiry about traditional governmental activity is aimed, it
entails neither tautology nor the hopeless effort to pick and choose
among legitimate governmental activity that led to Garcia v. San
Antonio Metropolitan Transit Authority, 469 U. S. 528 (1985).
One of the two fundamental points of difference between the Court
and the dissenters is their rejection of the constitutional distinction
between public and private preference, see post, at 6, 10, 12; the dis­
12 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

laws favoring a State’s municipal bonds, given that the
issuance of debt securities to pay for public projects is a
quintessentially public function, with the venerable his­
tory we have already sketched, see supra, at 4–5. By
issuing bonds, state and local governments “sprea[d] the
costs of public projects over time,” Amdursky & Gillette
§1.1.3, at 11, much as one might buy a house with a loan
subject to monthly payments. Bonds place the cost of a
project on the citizens who benefit from it over the years,
see ibid., and they allow for public work beyond what
current revenues could support, see id., §1.2, at 12–13.
Bond proceeds are thus the way to shoulder the cardinal
civic responsibilities listed in United Haulers: protecting
the health,10 safety,11 and welfare12 of citizens. It should
go without saying that the apprehension in United Haul­
ers about “unprecedented . . . interference” with a tradi­
tional government function is just as warranted here,
where the Davises would have us invalidate a century-old
taxing practice, see supra, at 5, presently employed by 41
States, see n. 7, supra, and affirmatively supported by all
of them, see Brief for 49 States as Amici Curiae.
In fact, this emphasis on the public character of the
enterprise supported by the tax preference is just a step in
addressing a fundamental element of dormant Commerce
Clause jurisprudence, the principle that “any notion of
——————
senters thus carry on the battle that was fought in United Haulers.
(The second fundamental difference goes to the realism and legitimacy
of treating bond issuance and tax provisions as aggregated features of a
single scheme of public finance. Compare infra, at 15–16, with post, at
6, 14.)
10 See, e.g., The Bond Buyer, Apr. 20, 2007, p. 31, col. 2 (describing

bond issue by the Grayson County Public Hospital District Corpora­
tion).
11 See, e.g., id., June 20, 2007, p. 29, col. 3 (describing bond issue by

Todd County for a “Detention Facility Project”).
12 See, e.g., id., Apr. 20, 2007, p. 31, cols. 2–3 (describing bond issue

by the Johnson County School District Finance Corporation).
 Cite as: 553 U. S. ____ (2008) 13

Opinion of the Court

discrimination assumes a comparison of substantially
similar entities.” United Haulers, 550 U. S., at ___ (slip
op., at 10) (internal quotation marks omitted) (quoting
General Motors Corp. v. Tracy, 519 U. S. 278, 298 (1997)).
In Bonaparte v. Tax Court, 104 U. S. 592 (1882), a case
involving the Full Faith and Credit Clause, we held that a
foreign State is properly treated as a private entity with
respect to state-issued bonds that have traveled outside its
borders. See id., at 595 (beyond its borders, a debtor State
“is compelled to go into the market as a borrower, subject
to the same disabilities in this particular as individuals,”
and has none “of the attributes of sovereignty as to the
debt it owes”). Viewed through this lens, the Kentucky tax
scheme parallels the ordinance upheld in United Haulers:
it “benefit[s] a clearly public [issuer, that is, Kentucky],
while treating all private [issuers] exactly the same.” 550
U. S., at ___ (slip op., at 10). There is no forbidden dis­
crimination because Kentucky, as a public entity, does not
have to treat itself as being “substantially similar” to the
other bond issuers in the market.13
Thus, United Haulers provides a firm basis for reversal.
Just like the ordinances upheld there, Kentucky’s tax
exemption favors a traditional government function with­
out any differential treatment favoring local entities over
substantially similar out-of-state interests. This type of
law does “not ‘discriminate against interstate commerce’
for purposes of the dormant Commerce Clause.” Id., at ___
(slip op., at 13).

——————
13 Contrary to the dissent, see post, at 11, we do not suggest that the

only market at issue here is a discrete market for Kentucky bonds. In
fact, we recognize that the relevant market can be conceived more
broadly. See infra, at 20–21. Our point goes not to the contours of the
market, but to the proper characterization of the various entities acting
in the market.
14 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court
Opinion of SOUTER, J.

B

This case, like United Haulers, may also be seen under
the broader rubric of the market participation doctrine,
although the Davises say that market participant cases
are inapposite here. In their view, we may not character­
ize state action under the Kentucky statutes as market
activity for public purposes, because this would ignore a
fact absent in United Haulers but central here: this is a
case about differential taxation, and a difference that
amounts to a heavier tax burden on interstate activity is
forbidden, see, e.g., Camps Newfound/Owatonna, Inc. v.
Town of Harrison, 520 U. S. 564 (1997) (invalidating
statute exempting charities from real estate and personal
property taxes unless conducted or operated principally for
the benefit of out-of-state residents); Fulton Corp., 516
U. S. 325 (striking down tax on corporate stock held by
state residents, where rate of tax was inversely propor­
tional to the corporation’s exposure to the State’s income
tax); Bacchus Imports, Ltd. v. Dias, 468 U. S. 263 (1984)
(holding excise tax on sale of liquor at wholesale unconsti­
tutional because it exempted some locally produced alco­
holic beverages).
The Davises make a fair point to the extent that they
argue that Kentucky acts in two roles at once, issuing
bonds and setting taxes, and if looked at as a taxing au­
thority it seems to invite dormant Commerce Clause
scrutiny of its regulatory activity, see Walling v. Michigan,
116 U. S. 446, 455 (1886) (“A discriminating tax imposed
by a State operating to the disadvantage of the products of
other States when introduced into the first mentioned
State, is, in effect, a regulation in restraint of commerce
among the States, and as such is a usurpation of the
power conferred by the Constitution upon the Congress”);
see also Camps Newfound, supra, at 578 (“[I]t is clear that
discriminatory burdens on interstate commerce imposed
by regulation or taxation may . . . violate the Commerce
 Cite as: 553 U. S. ____ (2008) 15

Opinion of the Court
Opinion of SOUTER, J.

Clause”); Tracy, supra, at 287 (“The negative or dormant
implication of the Commerce Clause prohibits state taxa­
tion . . . that discriminates against or unduly burdens
interstate commerce”).
But there is no ignoring the fact that imposing the
differential tax scheme makes sense only because Ken­
tucky is also a bond issuer. The Commonwealth has
entered the market for debt securities, just as Maryland
entered the market for automobile hulks, see Alexandria
Scrap, 426 U. S., at 806, and South Dakota entered the
cement market, see Reeves, 447 U. S., at 440. It simply
blinks this reality to disaggregate the Commonwealth’s
two roles and pretend that in exempting the income from
its securities, Kentucky is independently regulating or
regulating in the garden variety way that has made a
State vulnerable to the dormant Commerce Clause.
States that regulated the price of milk, see, e.g., West Lynn
Creamery, Inc. v. Healy, 512 U. S. 186 (1994); Baldwin v.
G. A. F. Seelig, Inc., 294 U. S. 511 (1935), did not keep
herds of cows or compete against dairy producers for the
dollars of milk drinkers. But when Kentucky exempts its
bond interest, it is competing in the market for limited
investment dollars, alongside private bond issuers and its
sister States, and its tax structure is one of the tools of
competition.14
The failure to appreciate that regulation by taxation
here goes hand in hand with market participation by
selling bonds allows the Davises to advocate the error of
focusing exclusively on the Commonwealth as regulator
and ignoring the Commonwealth as bond seller, see Brief
for Respondents 36–39, just as the state court did in say­
ing that “ ‘when a state chooses to tax its citizens, it is
——————
14 The dissent overlooks this discussion when it claims that we con­

tend Kentucky does not compete with other municipal bond issuers.
See post, at 8.
16 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court
Opinion of SOUTER, J.

acting as a market regulator[,]’ not as a market partici­
pant.” 197 S. W. 3d, at 564 (quoting Shaper, 97 Ohio App.
3d, at 764, 647 N. E. 2d, at 552).15 To indulge in this
single vision, however, would require overruling most, if
not all, of the cases on point decided since Alexandria
Scrap.
White, for example, also scrutinized a government acting
in dual roles. The mayor of Boston promulgated an execu­
tive order that bore the hallmarks of regulation: it applied
to every construction project funded wholly or partially by
city funds (or funds administered by the city), and it im­
posed general restrictions on the hiring practices of pri­
vate contractors, mandating that 50% of their work forces
be bona fide Boston residents and setting thresholds for
minorities (25%) and women (10%) as well. See 460 U. S.,
at 205, n. 1; see also id., at 218–219 (Blackmun, J., con­
curring in part and dissenting in part) (“The executive
order in this case . . . is a direct attempt to govern private
economic relationships. . . . [It] is the essence of regula­
tion”). At the same time, the city took part in the market
by “expend[ing] its own funds in entering into construction
contracts for public projects.” Id., at 214–215 (opinion of
the Court). After speaking of “ ‘[t]he basic distinction . . .
between States as market participants and States as
market regulators,’ ” id., at 207 (quoting Reeves, supra, at
436–437), White did not dissect Boston’s conduct and
ignore the former. Instead, the Court treated the regula­
tory activity in favor of local and minority labor as terms
or conditions of the government’s efforts in its market role,
which was treated as dispositive.
Similarly, in Alexandria Scrap, Maryland employed the
tools of regulation to invigorate its participation in the
market for automobile hulks. The specific controversy
there was over documentation requirements included in a
——————
15 The dissent does the same. See post, at 6, 14.
 Cite as: 553 U. S. ____ (2008) 17

Opinion of the Court
Opinion of SOUTER, J.

“comprehensive statute designed to speed up the scrap
cycle.” 426 U. S., at 796. Superficially, the scheme was
regulatory in nature; but the Court’s decision was prem­
ised on its view that, in practical terms, Maryland had not
only regulated but had also “entered into the market itself
to bid up [the] price” of automobile hulks. See id., at 806.
United Haulers, though not placed under the market
participant umbrella, may be seen as another example.
Not only did the public authority acting in that case proc­
ess trash, but its governmental superiors forbade trash
haulers to deal with any other processors. This latter fact
did not determine the outcome, however; the dispositive
fact was the government’s own activity in processing
trash. We upheld the government’s decision to shut down
the old market for trash processing only because it created
a new one all by itself, and thereby became a participant
in a market with just one supplier of a necessary service.
If instead the government had created a monopoly in favor
of a private hauler, we would have struck down the law
just as we did in C & A Carbone, Inc. v. Clarkstown, 511
U. S. 383 (1994). United Haulers accordingly turned on
our decision to give paramount consideration to the public
function in actively dealing in the trash market; if the
Davises had their way, United Haulers would be overruled
and the market participation doctrine would describe a
null set (or maybe a set of one, see Reeves, supra).
In each of these cases the commercial activities by the
governments and their regulatory efforts complemented
each other in some way, and in each of them the fact of
tying the regulation to the public object of the foray into
the market was understood to give the regulation a civic
objective different from the discrimination traditionally
held to be unlawful: in the paradigm of unconstitutional
discrimination the law chills interstate activity by creating
a commercial advantage for goods or services marketed by
local private actors, not by governments and those they
18 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court
Opinion of SOUTER, J.

employ to fulfill their civic objectives, see, e.g., Fulton
Corp., 516 U. S. 325 (higher tax on the stock of corpora­
tions with little or no presence in the State); New Energy
Co. of Ind., 486 U. S. 269 (tax credit to sellers of ethanol
available only for ethanol produced in the State); Bacchus
Imports, Ltd., 468 U. S. 263 (tax exemption that applied
only to sales of certain locally produced liquors); Lewis v.
BT Investment Managers, Inc., 447 U. S. 27 (1980) (prohi­
bition on out-of-state banks owning in-state businesses
that provided investment advisory services); Boston Stock
Exchange v. State Tax Comm’n, 429 U. S. 318 (1977)
(higher tax on sale of securities by nonresidents if the
securities were sold on an out-of-state, not an in-state,
exchange). In sum, our cases on market regulation with­
out market participation prescribe standard dormant
Commerce Clause analysis; our cases on market participa­
tion joined with regulation (the usual situation) prescribe
exceptional treatment for this direct governmental activity
in commercial markets for the public’s benefit.16
The Kentucky tax scheme falls outside the forbidden
paradigm because the Commonwealth’s direct participa­
tion favors, not local private entrepreneurs, but the Com­
monwealth and local governments. The Commonwealth
enacted its tax code with an eye toward making some or
all of its bonds more marketable. When it issues them for
sale in the bond market, it relies on that tax code, and
seller and purchaser treat the bonds and the tax rate as
joined just as intimately, say, as the work force require-
——————
16 Significantly,
our market participant cases are not limited to cases
where the government supplies a uniquely public product. This much
is manifest from Reeves, Inc. v. Stake, 447 U. S. 429 (1980). There is
nothing remarkable or inherently governmental about the cement
South Dakota produced, and yet we recognized that the State may
engage in clear discrimination against out-of-state buyers that regular
dormant Commerce Clause analysis would undoubtedly have held
unconstitutional.
 Cite as: 553 U. S. ____ (2008) 19

Opinion of the Court
Opinion of SOUTER, J.

ments and city construction contracts were in Boston.
Issuing bonds must therefore have the same significance
under the dormant Commerce Clause as government trash
processing, junk car disposal, or construction; and United
Haulers, Alexandria Scrap, and White can be followed only
by rejecting the Davises’ argument that Kentucky’s regu­
latory activity should be viewed in isolation as Commerce
Clause discrimination.17
——————
17 The dissent criticizes this analysis on the basis of our statement in

Camps Newfound/Owatonna, Inc. v. Town of Harrison, 520 U. S. 564,
593 (1997), that “[a] tax exemption is not the sort of direct state in­
volvement in the market that falls within the market-participation
doctrine.” See post, at 14. This both misses the point and leaves the
language from Camps Newfound shorn of context. In Camps New­
found, the tax exemption was unaccompanied by any market activity by
the State; it favored only private charitable institutions. We correctly
rejected the argument that a tax exemption without more constitutes
market participation. But we had no occasion to consider the scheme
here, where a State employs a tax exemption to facilitate its own
participation in the market. As noted before, one of the dissent’s
critical premises is the disaggregation of bond issuance and tax treat­
ment, see post, at 6, 14; that strikes us as a denial of economic reality.
The dissent also suggests that our reasoning conflicts with South-
Central Timber Development, Inc. v. Wunnicke, 467 U. S. 82 (1984), see
post, at 14–15, but there is no conflict. In South-Central, Alaska
conditioned the sale of state timber to private purchasers by requiring
that the timber be processed within the State prior to export, and a
plurality struck down the condition under the Commerce Clause. The
case turned on the plurality’s conclusion that the processing require­
ment constituted a “restrictio[n] on dispositions subsequent to the
goods coming to rest in private hands.” 467 U. S., at 98; see id., at 95
(“Under the Alaska requirement, . . . the choice is made for [the pur­
chaser]: if he buys timber from the State he is not free to take the
timber out of state prior to processing”). Kentucky imposes no such
restrictions on the disposition of Kentucky bonds; bond holders are free
to sell the bonds to whomever they please. Thus, the type of “down­
stream regulation” that South-Central found objectionable is simply not
present here. Id., at 99. We note also that South-Central expressly
applied “more rigorous” Commerce Clause scrutiny because the case
involved “foreign commerce” and restrictions on the resale of “a natural
resource.” Id., at 100, 96. Neither of those elements appears here.
20 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

C
A look at the specific markets in which the exemption’s
effects are felt both confirms the conclusion that no tradi­
tionally forbidden discrimination is underway and points
to the distinctive character of the tax policy. The market
as most broadly conceived is one of issuers and holders of
all fixed-income securities, whatever their source or ulti­
mate destination. In this interstate market, Kentucky
treats income from municipal bonds of other States just
like income from bonds privately issued in Kentucky or
elsewhere; no preference is given to any local issuer, and
none to any local holder, beyond what is entailed in the
preference Kentucky grants itself when it engages in
activities serving public objectives.
A more specialized market can be understood as com­
merce solely in federally tax-exempt municipal bonds,
much of it conducted through interstate municipal bond
funds.18 Here, of course, the distinction between the tax­
ing State’s bonds and their holders and issuers and hold­
ers of out-of-state counterparts is at its most stark. But
what is remarkable about the issuers in this and the

——————
18 See Brief for National Federation of Municipal Analysts as Amicus

Curiae 11 (hereinafter National Federation Brief) (“In 2006, tax-exempt
mutual funds held approximately $365 billion in long-term [municipal]
bonds, of which approximately $155 billion were held in 481 single-
state funds and approximately $210 billion in 230 national funds . . .
[and as of March 2007,] approximately $254 billion [in short-term
municipal bonds] were held in national tax-exempt money market
funds and approximately $125 billion in single state tax-exempt money
market funds” (citing Investment Company Institute, 2007 Investment
Company Fact Book 96, 98; Lipper Analytical Services, Tax-Exempt
Fixed Income Fund Performance Analysis, 1st Quarter 2007 Report));
National Federation Brief 12 (“[A]pproximately 58% of . . . long-term
municipal bonds [owned by mutual funds] and approximately 67% of
. . . short-term municipal securities were purchased without regard to a
match between the state of the bond issuer and the state of the fund’s
shareholders”).
 Cite as: 553 U. S. ____ (2008) 21

Opinion of the Court

broader interstate market is that nearly every taxing
State believes its public interests are served by the same
tax-and-exemption feature, which is supported in this
Court by every one of the States (with or without an in­
come tax) despite the ranges of relative wealth and tax
rates among them. See Brief for 49 States as Amici Cu­
riae. These facts suggest that no State perceives any local
advantage or disadvantage beyond the permissible ones
open to a government and to those who deal with it when
that government itself enters the market. See supra, at
14–18.
An equally significant perception emerges from examin­
ing the third type of market for municipal bonds: the one
for bonds within the State of issue, a large proportion of
which market in each State is managed by one or more
single-state funds. By definition, there is no discrimina­
tion against interstate activity within the market itself,
but one of its features reveals an important benefit of
intrastate bond markets as they operate through these
funds. The intrastate funds absorb securities issued by
smaller or lesser known municipalities that the interstate
markets tend to ignore. See National Federation Brief 15
(compared with single-state funds, “[n]ational mutual
funds . . . are less likely to dedicate the time necessary to
evaluate a small, obscure or infrequent municipal bond
issuer or to purchase bonds issued by such public enti­
ties”); id., at 19 (“[N]ational mutual funds place a higher
premium on the liquidity of their holdings than do single
state funds, which are willing to purchase less liquid
municipal bonds of smaller and less familiar issuers be­
cause of the state tax advantage and the fund’s mandate
to purchase bonds issued within a specific state”).
There is little doubt that many single-state funds would
disappear if the current differential tax schemes were
upset. See id., at 18 (“[O]ne predictable impact of the
elimination of tax incentives for the purchase of municipal
22 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

bonds issued in a specific state would be the disappear­
ance, through consolidation into national mutual funds, of
single state mutual funds”); ibid. (“Although a handful of
single state funds might continue to exist for a small
number of states (such as Florida) with high populations
that have a high affinity for local bond issuers, the current
state tax system is the raison d’être for virtually all single
state funds, and they would cease to be financially viable
in the absence of a tax advantage that outweighed their
relative lack of diversification vis-à-vis national funds and
their reduced asset base”); accord, Brief for Respondents
29 (the States’ tax exemptions “have fostered the growth of
funds that hold only the municipal bonds of a single state,”
which “[a]s compared [with] national tax-exempt bonds
funds . . . tend to be higher risk and higher cost”); 11
Kiplinger’s Retirement Report, Win With Home-State
Muni Bond Funds, p. 2 (Dec. 2004) (noting that in States
without a differential taxation scheme, “there’s little
incentive to create [single-state] muni bond funds”).
Nor is there any suggestion that the interstate markets
would discover some new reason to welcome the weaker
municipal issues that would lose their local market homes
after a victory for the Davises here. See National Federa­
tion Brief 18, 19 (“The main adverse impact of the disap­
pearance of single state funds . . . would be felt by small
municipal issuers” because they “would stand to lose much
of the intrastate market for the bonds that has developed
under the currently prevailing state tax system without
gaining much of an interstate market from its elimina­
tion”). Financing for long-term municipal improvements
would thus change radically if the differential tax feature
disappeared.19
——————
19 The Davises themselves, in their opposition to the petition, explain

that if the tax exemptions are removed, “states will open their invest­
ment sales to the entire national market for debt instruments.” Brief
 Cite as: 553 U. S. ____ (2008) 23

Opinion of the Court

This probable indispensability of the current scheme to
maintaining single-state markets serving smaller munici­
pal borrowers not only underscores how far the States’
objectives probably lie from the forbidden protectionism
for local business; it also tends to explain why the States
are so committed to a taxing practice that much scholar­
ship says often produces a net burden of tax revenues lost
over interest expense saved. See, e.g., Brief for Alan D.
Viard et al. as Amici Curiae 19 (“[S]tates routinely fail to
recoup the cost of the tax subsidy in the form of lower
financing rates” (citing Chalmers, Default Risk Cannot
Explain the Muni Puzzle: Evidence from Municipal Bonds
that are Secured by U. S. Treasury Obligations, 11 Rev.
Financial Studies 281, 282–283 (1998))).
In sum, the differential tax scheme is critical to the
operation of an identifiable segment of the municipal
financial market as it currently functions, and this fact
alone demonstrates that the unanimous desire of the
States to preserve the tax feature is a far cry from the
private protectionism that has driven the development of
the dormant Commerce Clause. It is also fatal to the
Davises’ backup argument that this case should be re­
manded for analysis under the rule in Pike, 397 U. S. 137.
IV
Concluding that a state law does not amount to forbid­
den discrimination against interstate commerce is not the
death knell of all dormant Commerce Clause challenges,
for we generally leave the courtroom door open to plain­
tiffs invoking the rule in Pike, that even nondiscrimina­
——————
in Opposition 10–11. As a result, the Davises say, “[o]nce states com­
pete in the financial markets without the protective benefit of coercive
tax schemes, they will have to be more selective in what projects they
choose to fund. . . . [T]he market will provide incentives for govern­
ments to be more careful in selecting and funding projects through bond
sales.” Id., at 11, n. 5.
24 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

tory burdens on commerce may be struck down on a show­
ing that those burdens clearly outweigh the benefits of a
state or local practice. See id., at 142. The Kentucky
courts made no Pike enquiry, and the Davises ask us to
remand for one now, see Brief for Respondents 43.
The Davises’ request for Pike balancing assumes an
answer to an open question: whether Pike even applies to
a case of this sort. United Haulers included a Pike analy­
sis, see 550 U. S., at ___–___ (slip op., at 14–15) (plurality
opinion), but our cases applying the market participant
exception have not, see, e.g., White, 460 U. S. 204; Alexan­
dria Scrap, 426 U. S. 794. We need not decide this ques­
tion today, however, for Kentucky has not argued that
Pike is irrelevant, see Reply Brief for Petitioners 2, n. 1,
and even on the assumption that a Pike examination
might generally be in order in this type of case, the cur­
rent record and scholarly material convince us that the
Judicial Branch is not institutionally suited to draw reli­
able conclusions of the kind that would be necessary for
the Davises to satisfy a Pike burden in this particular
case.
The institutional difficulty is manifest in the very train
of disadvantages that the Davises’ counsel attributes to
the current differential tax scheme:
“First, it harms out-of-state issuers (i.e., other States
and their subdivisions) by blocking their access to in­
vestment dollars in Kentucky. Second, it similarly
harms out-of-state private sellers (e.g., underwriters,
individuals, and investment funds) who wish to sell
their bonds in Kentucky. Third, it harms the national
municipal bond market and its participants by distort­
ing and impeding the free flow of capital. Fourth, it
harms Kentucky investors by promoting risky, high-
cost investment vehicles. Fifth, it harms the States
by compelling them to enact competing discriminatory
 Cite as: 553 U. S. ____ (2008) 25

Opinion of the Court

laws that decrease their net revenues.” Brief for Re­
spondents 9.
Even if each of these drawbacks does to some degree
eventuate from the system, it must be apparent to anyone
that weighing or quantifying them for a cost-benefit
analysis would be a very subtle exercise. It is striking,
after all, that most of the harms allegedly flowing directly
or indirectly to Kentucky’s sister States and their citizens
have failed to dissuade even a single State from support­
ing the current system; every one of them, including
States with no income tax, have lined up with Kentucky in
this case.
The prospect for reliable Pike comparison dims even
further when we turn to the benign function of the current
system flagged a moment ago. Is any court in a position to
evaluate the advantage of the current market for bonds
issued by the smaller municipalities, the ones with no
ready access to any other bond market than single-state
funds? Consider that any attempt to place a definite value
on this feature of the existing system would have to con­
front the what-if questions. If termination of the differen­
tial tax scheme jeopardized or eliminated most single-
state funds (as the cited authorities predict) would some
new source of capital take their place? Would the inter­
state markets accommodate the small issuers (as no cited
authorities predict), or would the financing in question be
replaced by current local taxation for long-term projects
(unlikely, considering that financially weaker borrowers
are involved), or would state governments assume respon­
sibility through their own bonds or by state taxation? Or
would capital to some degree simply dry up, eliminating a
class of municipal improvements?20 And if some new
——————
20 History bears out the concern that poorer places may have a harder

time taking on at least some types of local investments. See Goldin &
Katz, The Shaping of Higher Education: The Formative Years in the
26 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

source or sources of capital became available for these
improvements in a given State, how likely is it that the
new scheme would produce measurable net benefits to
other States seeking capital, and how perceptibly would it
produce a freer flow of funds? Money spent up front on
increased local or state taxation is no more available for
out-of-state investment than money invested in local
bonds; sinking funds would be obviated, but what would
the effect be on interstate capital flows?
What is most significant about these cost-benefit ques­
tions is not even the difficulty of answering them or the
inevitable uncertainty of the predictions that might be
made in trying to come up with answers, but the unsuit­
ability of the judicial process and judicial forums for mak­
ing whatever predictions and reaching whatever answers
are possible at all. See Tracy, 519 U. S., at 308 (“[T]he
Court is institutionally unsuited to gather the facts upon
which economic predictions can be made, and profession­
ally untrained to make them”); cf. Fulton Corp., 516 U. S.,
at 342 (“ ‘[C]ourts as institutions are poorly equipped to
evaluate with precision the relative burdens of various
methods of taxation. The complexities of factual economic
proof always present a certain potential for error, and
courts have little familiarity with the process of evaluating
the relative economic burden of taxes’ ” (quoting Minnea­
polis Star & Tribune Co. v. Minnesota Comm’r of Revenue,
460 U. S. 575, 589–590 (1983))).
While it is not our business to suggest that the current
system be reconsidered, if it is to be placed in question a
congressional forum has two advantages. Congress has
some hope of acquiring more complete information than
——————
United States, 1890 to 1940, 13 J. Econ. Perspectives 37, 50–55 (Winter
1999) (per capita spending on public universities depended on local
wealth); Goldin, America’s Graduation from High School: The Evolution
and Spread of Secondary Schooling in the Twentieth Century, 58 J.
Econ. Hist. 345, 369–372 (1998) (likewise for public high schools).
 Cite as: 553 U. S. ____ (2008) 27

Opinion of the Court

adversary trials may produce, and an elected legislature is
the preferable institution for incurring the economic risks
of any alteration in the way things have traditionally been
done. And risk is the essence of what the Davises are
urging here. It would miss the mark to think that the
Kentucky courts, and ultimately this Court, are being
invited merely to tinker with details of a tax scheme; we
are being asked to apply a federal rule to throw out the
system of financing municipal improvements throughout
most of the United States, and the rule in Pike was never
intended to authorize a court to expose the States to the
uncertainties of the economic experimentation the Davises
request.
* * *
The dissent rightly praises the virtues of the free mar­
ket, and it warns that our decision to uphold Kentucky’s
tax scheme will result in untoward consequences for that
market. See, e.g., post, at 15. But the warning is alarm­
ism; going back to 1919 the state regimes of differential
bond taxation have been elements of the national com­
merce without wilting the Commerce Clause. The threat
would come, instead, from the dissent’s approach, which to
a certainty would upset the market in bonds and the
settled expectations of their issuers based on the experi­
ence of nearly a century.
We have been here before. Our predecessors on this
Court responded to an earlier invitation to the adventur­
ism of overturning a traditional local taxing practice.
Justice Holmes answered that “the mode of taxation is of
long standing, and upon questions of constitutional law
the long settled habits of the community play a part . . . .
[T]he fact that the system has been in force for a very long
time is of itself a strong reason . . . for leaving any im­
provement that may be desired to the legislature.”
28 DEPARTMENT OF REVENUE OF KY. v. DAVIS

Opinion of the Court

Paddell v. City of New York, 211 U. S. 446, 448 (1908).21
The judgment of the Court of Appeals of Kentucky is
reversed, and the case is remanded for further proceedings
not inconsistent with this opinion.
It is so ordered.

——————
21 The dissent thinks the need to preserve existing financing practices
is the true “controlling rationale” of our holding, post, at 15, but not
acknowledged as such. As Justice Holmes’s opinion shows, practical
consequences have always been relevant in deciding the constitutional­
ity of local tax laws. The practical considerations discussed here
support the traditional distinction between permissible public prefer­
ences and the forbidden discriminations for the benefit of local private
interests.
 Cite as: 553 U. S. ____ (2008) 1

STEVENS, J., concurring

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

JUSTICE STEVENS, concurring.
Having dissented in both Reeves, Inc. v. Stake, 447 U. S.
429 (1980), and United Haulers Assn., Inc. v. Oneida-
Herkimer Solid Waste Management Authority, 550 U. S.
___ (2007), it seems appropriate to state briefly why I
would join the Court’s opinion even if those cases had been
decided differently. Reeves and United Haulers involved
state participation in commercial markets—the market for
cement in Reeves and the market for waste disposal in
United Haulers. The state entities in those cases imposed
burdens on the private market for commercial goods and
services. In this case Kentucky and its local governmental
units engage in no private trade or business; they are
merely borrowers of funds needed to finance public
improvements.
Putting to one side cases in which a State may create a
“market that did not previously exist,” see Hughes v.
Alexandria Scrap Corp., 426 U. S. 794, 815 (1976)
(STEVENS, J., concurring), I agree with Justice Powell’s
view that when a “State enters the private market and
operates a commercial enterprise for the advantage of its
private citizens, it may not evade the constitutional policy
against economic Balkanization.” Reeves, 447 U. S., at
449–450 (dissenting opinion). On the other hand, if a
State merely borrows money “to pay for spending on
2 DEPARTMENT OF REVENUE OF KY. v. DAVIS

STEVENS, J., concurring

transportation, public safety, education, utilities, and
environmental protection,” ante, at 3, it does not “operat[e]
a commercial enterprise” for purposes of the dormant
Commerce Clause. As the majority of this Court stressed
in C & A Carbone, Inc. v. Clarkstown, 511 U. S. 383
(1994)—and JUSTICE ALITO reiterated in his dissent in
United Haulers—instead of enacting “flow control” waste
disposal ordinances, the local governments would have
been
“free, of course, to ‘subsidize the[ir] [program] through
general taxes or municipal bonds. But having elected
to use the open market to earn revenues for’ their
waste management program, [they] ‘may not employ
discriminatory regulation to give that [program] an
advantage over rival businesses from out of State.’ ”
550 U. S., at ___ (slip op., at 14) (quoting Carbone, 511
U. S., at 394; citation omitted).
A State’s reliance on “general taxes or municipal bonds” to
finance public projects does not merit the same Commerce
Clause scrutiny as “operating a fee-for-service business
enterprise in an area in which there is an established
interstate market.” 550 U. S., at ___ (slip op., at 8)
(ALITO, J., dissenting). I am not persuaded that the Com-
merce Clause analysis should change just because Ken-
tucky chooses to make the interest it pays on its own
municipal bonds, which is already tax exempt under fed-
eral law, also tax exempt under Kentucky law.
The citizens of Kentucky provide the natural market for
the purchase of Kentucky’s bonds because they are also
the beneficiaries of the programs being financed. More-
over, it is their tax payments that will enable Kentucky to
pay the interest on the bonds and to discharge its indebt-
edness. The tax exemption for Kentucky citizens en-
hances the marketability of Kentucky bonds in the Ken-
tucky market, motivating local support for local public
 Cite as: 553 U. S. ____ (2008) 3

STEVENS, J., concurring

improvements. Instead of issuing bonds, Kentucky could
have borrowed funds from a Kentucky bank or issued
notes to a syndicate of Kentucky lenders without implicat-
ing the Commerce Clause, even though such fundraising
would preclude an equal amount of money in Kentucky
from entering the interstate market for bonds.* Free
tickets to the Kentucky Derby for purchasers of the bonds
would have a comparable, though presumably lesser,
effect. In my judgment state action that motivates the
State’s taxpayers to lend money to the State is simply not
the sort of “burden” on interstate commerce that is impli-
cated by our dormant Commerce Clause jurisprudence.

——————
* Indeed, Kentucky could have just increased taxes. By issuing bonds
in lieu of increasing taxes, Kentucky has enlarged the interstate
market for securities, as well as increased the money available to
Kentucky citizens to partake in this market.
 Cite as: 553 U. S. ____ (2008) 1

ROBERTS, C. J., concurring in part

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

CHIEF JUSTICE ROBERTS, concurring in part.
I join all but Part III–B of the opinion of the Court. In
my view, the case is readily resolved by last Term’s deci-
sion in United Haulers Assn., Inc. v. Oneida-Herkimer
Solid Waste Management Authority, 550 U. S. ___ (2007).
A majority of the Court shares this view. That being the
case, I see no need to proceed to the alternative analysis in
Part III–B.
 Cite as: 553 U. S. ____ (2008) 1

SCALIA, J., concurring in part

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

JUSTICE SCALIA, concurring in part.
I join all but Part III–B and Part IV of the opinion of the
Court. I will apply our negative Commerce Clause doc-
trine only when stare decisis compels me to do so. In my
view it is “an unjustified judicial invention, not to be
expanded beyond its existing domain.” General Motors
Corp. v. Tracy, 519 U. S. 278, 312 (1997) (SCALIA, J., con-
curring). Stare decisis does not compel invalidation of
Kentucky’s statute. As the Court explains, it would be no
small leap from invalidating state discrimination in favor
of private entities to invalidating state discrimination in
favor of the State’s own subdivisions performing a tradi-
tional governmental function. To apply the negative
Commerce Clause in this area would broaden the doctrine
“ ‘beyond its existing scope, and intrude on a regulatory
sphere traditionally occupied by . . . the States.’ ” United
Haulers Assn., Inc. v. Oneida-Herkimer Solid Waste Man-
agement Authority, 550 U. S. ___, ___ (2007) (slip op., at 2)
(SCALIA, J., concurring in part) (omission in original).
That is enough for me.
I do not join Part III–B of the opinion of the Court be-
cause I think Part III–A adequately resolves the issue. I
also do not join Part IV, which describes the question
whether so-called Pike balancing applies to laws like this
as an “open” one. Ante, at 24. The Court declines to en-
2 DEPARTMENT OF REVENUE OF KY. v. DAVIS

SCALIA, J., concurring in part

gage in Pike balancing here because courts are ill suited to
determining whether or not this law imposes burdens on
interstate commerce that clearly outweigh the law’s local
benefits, and the “balancing” should therefore be left to
Congress. See ante, at 24–27. The problem is that courts
are less well suited than Congress to perform this kind of
balancing in every case. The burdens and the benefits are
always incommensurate, and cannot be placed on the
opposite balances of a scale without assigning a policy-
based weight to each of them. It is a matter not of weigh-
ing apples against apples, but of deciding whether three
apples are better than six tangerines. Here, on one end of
the scale (the burden side) there rests a certain degree of
suppression of interstate competition in borrowing; and on
the other (the benefits side) a certain degree of facilitation
of municipal borrowing. Of course you cannot decide
which interest “outweighs” the other without deciding
which interest is more important to you. And that will
always be the case. I would abandon the Pike-balancing
enterprise altogether and leave these quintessentially
legislative judgments with the branch to which the Consti-
tution assigns them. See Bendix Autolite Corp. v. Mid-
wesco Enterprises, Inc., 486 U. S. 888, 897–898 (1988)
(SCALIA, J., concurring in judgment).
 Cite as: 553 U. S. ____ (2008) 1

THOMAS, J., concurring in judgment

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

JUSTICE THOMAS, concurring in the judgment.
I agree with the Court that Kentucky’s differential tax
scheme is constitutional. But rather than apply a body of
doctrine that “has no basis in the Constitution and has
proved unworkable in practice,” I would entirely “discard
the Court’s negative Commerce Clause jurisprudence.”
United Haulers Assn., Inc. v. Oneida-Herkimer Solid
Waste Management Authority, 550 U. S. ___, ___ (2007)
(slip op., at 1) (THOMAS, J., concurring in judgment). See
also American Trucking Assns., Inc. v. Michigan Pub. Serv.
Comm’n, 545 U. S. 429, 439 (2005) (same) (“‘[T]he negative
Commerce Clause has no basis in the text of the Constitu-
tion, makes little sense, and has proved virtually unwork-
able in application’ ” (quoting Camps Newfound/Owatonna,
Inc. v. Town of Harrison, 520 U. S. 564, 610 (1997)
(THOMAS, J., dissenting))). Because Congress’ authority to
regulate commerce “among the several States,” U. S.
Const., Art. I, §8, cl. 3, necessarily includes the power “to
prevent state regulation of interstate commerce,” United
Haulers, supra, at ___ (slip op., at 2) (THOMAS, J., concur-
ring in judgment), the text of the Constitution makes clear
that the Legislature—not the Judiciary—bears the re-
sponsibility of curbing what it perceives as state regula-
tory burdens on interstate commerce.
As the Court acknowledges, Kentucky’s differential tax
2 DEPARTMENT OF REVENUE OF KY. v. DAVIS

THOMAS, J., concurring in judgment

scheme is far from unique. Ante, at 1. For nearly a cen-
tury, some States have treated income derived from out-of-
state bonds differently than that derived from their in-
state counterparts. Ibid. At present, the vast majority of
the States do so. Ante, at 5. The practice is thus both
longstanding and widespread, yet Congress has refrained
from preempting it. Cf. New Jersey Realty Title Ins. Co. v.
Division of Tax Appeals of N. J., 338 U. S. 665, 671 (1950)
(holding that a federal statute exempting interest-bearing
obligations of the United States from state and local taxa-
tion pre-empted a conflicting state statute). In the “face of
[this] congressional silence,” United Haulers, supra, at ___
(slip op., at 5) (THOMAS, J., concurring in judgment), we
have no authority to invalidate Kentucky’s differential tax
scheme. I would reverse the judgment below on that
basis.
 Cite as: 553 U. S. ____ (2008) 1

KENNEDY, J., dissenting

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

JUSTICE KENNEDY, with whom JUSTICE ALITO joins,
dissenting.
Eighteenth-century thinkers, even those most prescient,
could not foresee our technological and economic interde-
pendence. Yet they understood its foundation. Free trade
in the United States, unobstructed by state and local
barriers, was indispensable if we were to unite to ensure
the liberty and progress of the whole Nation and its peo-
ple. This was the vision, and a primary objective, of the
Framers of the Constitution. History, as we know, vindi-
cates their judgment. The national, free market within
our borders has been a singular force in shaping the con-
sciousness and creating the reality that we are one in
purpose and destiny. The Commerce Clause doctrine that
emerged from the decisions of this Court has been appro-
priate and necessary to implement the Constitution’s
purpose and design.
These general observations are offered at the outset to
underscore the imprudent risk the Court now creates by
misinterpreting our precedents to decide this case. True,
the majority opinion, wrong as it is, will not threaten the
whole economy or national unity on these facts alone. The
explicit, local discrimination the Court ratifies today likely
will result in extra, though manageable, accommodation
costs and can be welcomed by existing interests ready to
2 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

profit from it. This market perhaps can absorb the costs of
discrimination; our jurisprudence, unless the decision
stands alone as an anomaly, cannot.
Reactive institutions and adjusting forces—for instance
mutual funds for state and municipal bonds issued within
a single State—already are in place in response to the
local protectionist laws here at issue and now in vogue.
These mechanisms may allow the market, though neces-
sarily distorted by deviation from essential constitutional
principles, to continue to cope in a more or less efficient
manner; and the damage likely will be limited to the
discrete, and now distorted, market for state and munici-
pal bonds. Many economists likely will find it unfortu-
nate, and inefficient, that a specialized business has
emerged to profit from a departure from constitutional
principles. Even if today’s decision is welcomed by those
who profit from the discrimination, the system as a whole
would benefit from a return to a market with proper form,
freed from artificial restraints. It does seem necessary,
however, to point out the systemic consequences of today’s
decision—if only to confine it and to discourage new ex-
periments with local laws that discriminate against inter-
state commerce and trade.
The incorrect result the majority reaches; its treatment
of the Commerce Clause cases in which our predecessors
reached a delicate, sensible implementation of the Fram-
ers’ original purpose; and the unsatisfactory, brief, circular
reasoning contained in the part of the opinion that com-
mands a majority of the Court are all inconsistent with
our precedents and require this respectful dissent.
Protectionist trade laws and policies, pursued to favor
local interests within a larger trading area, invite prompt
retaliatory response. This dynamic was one the Framers
understood in theory and saw in fact. See, e.g., West Lynn
Creamery, Inc. v. Healy, 512 U. S. 186, 193, n. 9 (1994).
Under the Articles of Confederation the States enacted
 Cite as: 553 U. S. ____ (2008) 3

KENNEDY, J., dissenting

protectionist laws. It proved difficult and costly, even in
terms of political energies, to remove trade barriers by
negotiated agreements; and the few resulting compacts
seemed destined to favor the more powerful States. The
immediate prospect of escalating trade barriers was real,
and a national power to regulate national trade and re-
move local barriers soon was deemed urgent. Open mar-
kets and the elimination of trade barriers were the very
concerns that led to the Annapolis Convention of 1786.
See, e.g., E. Morgan, The Birth of the Republic, 1763–89,
p. 129 (1956). The frustrations of that meeting built a
strong consensus for the necessity of a larger compact and
led to the call for the Philadelphia Convention. See, e.g., 1
S. Morison, H. Commager, & W. Leuchtenburg, The
Growth of the American Republic 244 (rev. 6th ed. 1969).
The object of creating free trade throughout a single na-
tion, without protectionist state laws, was a dominant
theme of the convention at Philadelphia and during the
ratification debates that followed. See, e.g., The Federalist
No. 22, pp.143–144 (C. Rossiter ed. 1961) (A. Hamilton)
(“It is indeed evident, on the most superficial view,
that there is no object, either as it respects the interest of
trade or finance, that more strongly demands a federal
superintendence”).
This dissent will not repeat an earlier, brief account of
our Commerce Clause jurisprudence. See United States v.
Lopez, 514 U. S. 549, 568–583 (1995) (KENNEDY, J., con-
curring). The cases from Gibbons v. Ogden, 9 Wheat. 1
(1824), to Willson v. Black Bird Creek Marsh Co., 2 Pet.
245 (1829), and then through Cooley v. Board of Wardens
of Port of Philadelphia ex rel. Soc. for Relief of Distressed
Pilots, 12 How. 299 (1852), began the elaboration of a rule
respectful of local laws and local expertise, while preserv-
ing the theory and fact of free trade throughout the Na-
tion. Though an oversimplification, it suffices here to note
that our commerce cases have invalidated two types of
4 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

local barriers: laws that impose unreasonable burdens
upon interstate commerce; and laws that discriminate
against it.
The doctrine invalidating laws that impose unreason-
able burdens upon interstate commerce no doubt has been
a deterrent to local enactments attempting to regulate in
ways that restrict a free, national market. The corollary
rule that nondiscriminatory laws imposing a reasonable
burden are valid allows the States to exercise their powers
based on information and expertise more readily available
to them than to the National Government. The result is to
eliminate the demand and necessity for sweeping national
legislation. This line of cases has found occasional detrac-
tors. See, e.g., CTS Corp. v. Dynamics Corp. of America,
481 U. S. 69, 95 (1987) (SCALIA, J., concurring in part and
concurring in judgment); Southern Pacific Co. v. Arizona
ex rel. Sullivan, 325 U. S. 761, 790–795 (1945) (Black, J.,
dissenting). The undue burden rule, however, remains an
essential safeguard against restrictive laws that might
otherwise be in force for decades until Congress can act.
Those cases were the background for the formulation used
in Pike v. Bruce Church, Inc., 397 U. S. 137 (1970), which
is in essence ignored by the decision in today’s case. See
ante, at 23–27. The Court’s precedents discussing the
undue burden principle, and Pike, need not be addressed
here, however.
That is because the law in question is invalid under a
second line of precedents. These cases instruct that laws
with either the purpose or the effect of discriminating
against interstate commerce to protect local trade are
void. These are the authorities relevant to the only part of
the opinion that commands a majority, see ante, at 11–13,
and it is necessary to address the reasons the Court ad-
vances in seeking to disregard them.
 Cite as: 553 U. S. ____ (2008) 5

KENNEDY, J., dissenting

I
The Court defends the Kentucky law by explaining that
it serves a traditional government function and concerns
the “cardinal civic responsibilities” of protecting health,
safety, and welfare. See ante, at 12, and nn. 10–12. This
is but a reformulation of the phrase “police power,” long
abandoned as a mere tautology. It is difficult to identify
any state law that has come before us that would not meet
the Court’s description. That is why, with the unfortunate
recent exception of United Haulers Assn., Inc. v. Oneida-
Herkimer Solid Waste Management Authority, 550 U. S.
___ (2007), the Court had ceased to view the concept as
saying anything instructive. A law may contravene a
provision of the Constitution even if enacted for a benefi-
cial purpose.
The police power concept is simply a shorthand way of
saying that a State is empowered to enact laws in the
absence of constitutional constraints; but, of course, that
only restates the question. That a law has the police
power label—as all laws do—does not exempt it from
Commerce Clause analysis. The Court said this in a case
striking down an order, based upon local flood control
needs, directing a railroad to remove certain bridges and
raise others that supported rail lines involved in interstate
commerce: “[A] State cannot avoid the operation of [the
Commerce Clause] by simply invoking the convenient
apologetics of the police power.” Kansas City Southern R.
Co. v. Kaw Valley Drainage Dist., 233 U. S. 75, 79 (1914)
(opinion for the Court by Holmes, J.).
The Court holds the Kentucky law is valid because bond
issuance fulfills a governmental function: raising revenue
for public projects. See ante, at 11–12. Aside from the
point that this is but an extension of the police power
(“this is a good law”) argument, the premise is wrong. The
law in question operates on those who hold the bonds and
trade them, not those who issue them. The bonds are not
6 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

issued with a covenant promising tax exemption or tax
relief to the holder. The bonds contain no such provision.
The security is issued as a formal obligation to repay. Not
a word in the terms and conditions of the securities prom-
ises favored tax treatment for certain holders. Indeed,
that could not be done without impairing marketability. It
is simply not commercial or investment practice to make
payment obligations turn upon either the residence of the
holder or the State of the issuer. The issuer intends to use
the interstate market for its bonds and does not encumber
them with conditions giving premiums or penalties de-
pending upon the residence of the holders.
Even if the Court were correct to say the relevant legal
framework is bond issuance, not taxation of bonds already
issued, its conclusion would be incorrect; for the discrimi-
nation against out-of-state commerce still would be too
plain and prejudicial to be sustained. See, e.g., United
Haulers, supra, at ___ (slip op., at 15) (ALITO, J., dissent-
ing) (“[T]o the extent [the majority’s] holding rests on a
distinction between ‘traditional’ governmental functions
and their nontraditional counterparts, it cannot be recon-
ciled with prior precedent” (citation omitted)). The insuffi-
ciency of the Court’s reasoning is even more apparent,
however, because its own premise is incorrect. The chal-
lenged state activity is differential taxation, not bond
issuance. The state tax provision at issue could be re-
pealed tomorrow without altering or impairing a single
obligation in the bonds. It is the tax that matters; and
Kentucky gives favored tax treatment to some securities
but not others depending solely upon the State of issuance,
and it does so to disadvantage bonds from other States.
Our cases establish this rule: A State has no authority
to use its taxing power to erect local barriers to out-of-
state products or commodities. See, e.g., West Lynn, 512
U. S., at 193 (“The paradigmatic example of a law dis-
criminating against interstate commerce is the protective
 Cite as: 553 U. S. ____ (2008) 7

KENNEDY, J., dissenting

tariff or customs duty, which taxes goods imported from
other States, but does not tax similar products produced in
State”). Nothing in our cases even begins to suggest this
rule is inapplicable simply because the State uses a dis-
criminatory tax to favor its own enterprise. The tax im-
posed here is an explicit discrimination against out-of-
state issuances for admitted protectionist purposes. It
cannot be sustained unless the Court disavows the dis-
crimination principle, one of the most important pro-
tections we have elaborated for the Nation’s interstate
markets.
The Court has ruled that protectionist, differential
taxation with respect to securities sales is invalid. Boston
Stock Exchange v. State Tax Comm’n, 429 U. S. 318
(1977). In that case the Court considered the validity of a
New York transfer tax on securities transactions. New
York taxed out-of-state sales more heavily than in-state
sales. The transactions in question were concluded on
stock exchanges, such as the Boston Stock Exchange,
located outside New York State. All conceded the transac-
tions had sufficient contacts with New York so it could
impose a tax; the question was the validity of a higher rate
on transactions closed on exchanges located out-of-state.
The Court’s unanimous opinion held that the discrimina-
tory tax, designed to favor New York, was invalid. Id., at
328. “[I]n the process of competition no State may dis-
criminatorily tax the products manufactured or the busi-
ness operations performed in any other State.” Id., at 337.
The same was true of the discriminatory tax exemption
in Bacchus Imports, Ltd. v. Dias, 468 U. S. 263 (1984),
which the Court invalidated after observing that “as long
as there is some competition between the locally produced
exempt products and nonexempt products from outside the
State, there is a discriminatory effect.” Id., at 271. This
principle refutes the majority’s contention, see ante, at 12–
13, that Kentucky’s bonds do not compete with other state
8 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

or local government bonds. The relevant inquiry is not the
purpose of a bond but whether the bond is a product that
competes. The majority cannot establish that, from an
investor’s standpoint, Kentucky’s bonds do not compete
with bonds from other state or municipal governments.
Indeed, that competition is why the bonds need the advan-
tages the exemptions give them. Nothing in Bacchus
suggested its holding was dependent upon the private
nature of the favored competitors. Instead, in rejecting
the argument that discriminatory taxation was justified
because the goal was to promote local industry, the Court
explained that the “determination of constitutionality”
does not depend upon “the benefited or the burdened
party.” 468 U. S., at 273. This reasoning does not permit
a different outcome when the State is the “benefited
party.”
The Court had little difficulty in holding invalid a dis-
criminatory tax in Fulton Corp. v. Faulkner, 516 U. S. 325
(1996). There North Carolina had devised a tax on intan-
gibles that employed a deduction scheme favoring those
who owned stock in local companies by, in effect, taxing at
a higher rate those who owned stock in out-of-state com-
panies. Id., at 327–328. The Fulton scheme favored “do-
mestic corporations over their foreign competitors in rais-
ing capital among North Carolina residents and tend[ed],
at least, to discourage domestic corporations from plying
their trades in interstate commerce.” Id., at 333. The
Court held the scheme invalid as contrary to the Com-
merce Clause. See id., at 347.
Differential taxation favoring local trade over interstate
commerce poses serious threats to the national free mar-
ket because the taxing power is at once so flexible and so
potent. The Court’s differential tax cases are mentioned
here at the outset because taxation is the issue; and dis-
criminatory tax schemes are relatively rare, if only be-
cause they resemble tariffs—the “paradigmatic . . . law[s]
 Cite as: 553 U. S. ____ (2008) 9

KENNEDY, J., dissenting

discriminating against interstate commerce,” West Lynn,
512 U. S., at 193. See ibid. (“[T]ariffs against the products
of other States are so patently unconstitutional that our
cases reveal not a single attempt by any State to enact
one. Instead, the cases are filled with state laws that
aspire to reap some of the benefits of tariffs by other
means”).
The precedents forbidding discriminatory taxes are a
subset of a larger class of cases that invalidate other
regulations that favor local interests. These cases, too, are
inconsistent with the Court’s holding today. Bonds are
commodities in interstate commerce, and in this respect
consumers are entitled to choose them over local products
just as with milk, Dean Milk Co. v. Madison, 340 U. S. 349
(1951); apples, Hunt v. Washington State Apple Advertis-
ing Comm’n, 432 U. S. 333 (1977); solid waste for landfill,
Fort Gratiot Sanitary Landfill, Inc. v. Michigan Dept. of
Natural Resources, 504 U. S. 353 (1992); solid waste for
transfer, C & A Carbone, Inc. v. Clarkstown, 511 U. S. 383
(1994); out-of-state waste, Philadelphia v. New Jersey, 437
U. S. 617 (1978); and ethanol, New Energy Co. of Ind. v.
Limbach, 486 U. S. 269 (1988) (a differential tax case).
Cases on export controls—though of less relevance here—
provide further instruction for the simple proposition that
the national market cannot be isolated for protectionist or
local purposes. See, e.g., Hughes v. Oklahoma, 441 U. S.
322 (1979) (striking down a state law prohibiting the
shipment of minnows out of State); New England Power
Co. v. New Hampshire, 455 U. S. 331 (1982) (striking
down a state law requiring the state utility commission’s
permission before a utility could convey electricity out of
State).
In the only part of the Court’s opinion that commands a
majority the main point is that validation of Kentucky’s
tax exemption follows from the Court’s opinion last Term
in United Haulers. But that overlooks the argument that
10 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

was central to the entire holding of United Haulers. There
the Court concluded the ordinance applied equally to
interstate and in-state commerce—and so it applied with-
out differentiation between in-state and out-of-state com-
merce—because the government had monopolized the
waste processing industry. See United Haulers, 550 U. S.,
at ___ (slip op., at 1). Nondiscrimination, not just state
involvement, was central to the rationale. That justifica-
tion cannot be invoked here, for discrimination against
out-of-state bonds is the whole purpose of the law in ques-
tion. Kentucky has not monopolized the bond market or
the municipal bond market. Kentucky has entered a
competitive, nonmonopolized market and, to give its bonds
a market advantage, has taxed out-of-state municipal
bonds at a higher rate. The explicit rationale of the law is
to differentiate between local and interstate commodities.
This case is not an extension of United Haulers; it is a
rejection of its principal rationale—that in monopolizing
the local market, the ordinance applied equally to inter-
state and local commerce.
The Court’s next argument is the police power argu-
ment, returning to the idea that revenue-raising is impor-
tant for a State’s own essential projects. See ante, at 11–
12. This argument has two major flaws. First, it is a
replay of the circularity inherent in the police powers,
health, safety, and welfare rhetoric. It is difficult to think
of any law meeting with general approval that, assuming
its validity in other respects, would fall outside the de-
scription that it is for the health, safety, and welfare of its
citizens. Second, the argument ignores the fact that all
protectionist laws, by definition, can be justified to further
some local interest.
In a case with important parallels to this one the Court
considered whether a property tax exemption available to
charitable and benevolent organizations in Maine could
have differential application in order to advantage camps
 Cite as: 553 U. S. ____ (2008) 11

KENNEDY, J., dissenting

that served primarily Maine residents as distinct from
camps that served primarily out-of-state residents. See
Camps Newfound/Owatonna, Inc. v. Town of Harrison,
520 U. S. 564 (1997). The Court was explicit in rejecting
the argument that profit and not-for-profit organizations
should be treated differently with respect to Commerce
Clause protection, id., at 584, despite the State’s special,
historic concern for charitable assistance within its own
borders. The Camps Newfound analysis is applicable
here: There is “no reason why the nonprofit character of
an enterprise should exclude it from the coverage of either
the affirmative or the negative aspect of the Commerce
Clause.” Ibid. So, too, there is no reason the governmen-
tal character of the bond-issuing enterprise should exclude
it from the coverage of the Commerce Clause.
The majority concludes its central framework by saying
the market for Kentucky’s bonds is not similar to the
market for private issuers because it is the Common-
wealth’s own discrete market. So, it says, Kentucky can
discriminate if it chooses. Quite apart from the principle
that discrimination in explicit terms, purpose, and effect
should invalidate this law, the Court’s argument proceeds,
again, from a wrong and circular premise. The argument
that Kentucky bonds are in a discrete market has no basis
in the record. Kentucky state and local bonds compete
with other bonds, as any investor knows. Within the
national bond market there is a discrete submarket for all
state and municipal bonds because they are tax exempt
under the Internal Revenue Code. See ante, at 2 (citing 26
U. S. C. §103(a)). The Court, however, goes on to suggest
that within this separate market there are 41 further
discrete markets for bonds in each of the separate States
that have laws like the one before the Court. Ante, at 12–
13. This is wrong because it defines the market based
upon sellers’ purposes rather than upon its investors’
purposes. The latter are the touchstone of market defini-
12 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

tion. The Court’s seller-based definition is at odds with
our Commerce Clause jurisprudence. The question has
never been what the beneficiary of the discriminatory law
will do with that benefit; that question relates to the ends
sought by the discriminatory means. See, e.g., Bacchus,
468 U. S., at 272–273; see also United Haulers, supra, at
___ (slip op., at 12–13) (ALITO, J., dissenting).
The issue in this case, then, cannot be resolved by de-
termining what the issuer does with the proceeds. And to
the extent the Court says there is a consumer preference
for a State’s own bonds within its own borders, this makes
the mistake of defining a market by first assuming the
validity of the discriminatory law at issue. No precedent
permits the Court to define a market in terms of the very
law under challenge for protectionist purposes and effects.
This double counting does not work. If the discriminatory
barrier did not exist, then the national market for all state
and municipal bonds would operate like other free, na-
tionwide markets. The fact that the national market for
tax-free state and municipal bonds is a discrete one serves
only to reinforce the point that it should operate without
local restriction.
That the people in each of 49 States that joined a brief
in support of Kentucky are alleged to want the law is
irrelevant. See ante, at 21. Protectionist interests always
want the laws they pass, even if their fellow citizens bear
the burden, for they are positioned to profit from the
barrier. The circumstance that the residents choose to
bear the costs of a protectionist measure (assuming this to
be so even though entrenched interests are the usual
source for the law) has been found by this Court to be
quite irrelevant: “This argument, if accepted, would un-
dermine almost every discriminatory tax case. State taxes
are ordinarily paid by in-state businesses and consumers,
yet if they discriminate against out-of-state products, they
are unconstitutional.” West Lynn, 512 U. S., at 203; see
 Cite as: 553 U. S. ____ (2008) 13

KENNEDY, J., dissenting

also Bacchus, supra, at 272.
That 41 States have local protectionist laws similar to
this one proves the necessity of allowing settled principles
against discrimination to operate in an important national
market. The Court seems proud to say that New York was
the first to enact a protectionist exemption. See ante, at 5.
That, too, simply underscores the importance of adhering
to the rules against state trade discrimination. New York,
as a great financial capital, likely had no trouble raising
money for its own bonds, and so its exemption might have
been thought to be an advantage in some respects. The
exemption benefits wealthy, high-tax States, allowing
those States to hoard capital that otherwise might travel
to issuers who offer a more competitive deal in pretax
dollars. See, e.g., Blumstein, Some Intersections of the
Negative Commerce Clause and the New Federalism: The
Case of Discriminatory State Income Tax Treatment of
Out-of-State Tax-Exempt Bonds, 31 Vand. L. Rev. 473, 546
(1978).
In the wake of one trade barrier, retaliatory measures
follow, as the Framers well knew. The widespread nature
of these particular trade barriers illustrates the standard
dynamics of politics and economics, demonstrating once
more the need to avoid validating this law as somehow in
the States’ own interests. By misapplying the rationales
of the controlling precedents, the Court invites further
erosion of the Commerce Clause, which must remain as a
deterrent to experiments designed to serve local interests
at the expense of a national system.
The Court’s categorical approach would seem to allow
States to discriminate against out-of-state, government
bonds in other ways. Nothing in the Court’s rationale
justifying this scheme would stop Kentucky from taxing
interest on out-of-state bonds at a high rate, say 80%,
simply to give its own bonds further advantage. High tax
rates designed to make out-of-state interests less attrac-
14 DEPARTMENT OF REVENUE OF KY. v. DAVIS

KENNEDY, J., dissenting

tive are not unheard of in our cases. See, e.g., Fulton, 516
U. S., at 333. Today the Court upholds a scheme no differ-
ent in kind from those patently unconstitutional schemes.
Furthermore, the Court’s approach would permit a State
to condition tax-free treatment of out-of-state bonds on
reciprocal treatment in another State, see ante, at 5–6,
n. 7 (citing, for example, Utah’s reciprocal tax-free treat-
ment of States that do not tax Utah bonds), leading to the
discrete market blocs the Constitution was designed to
eliminate. These examples underscore the objections
already noted.
II
In a part of the opinion joined only by a plurality the
analysis concludes the differential taxation scheme is a
sufficiently diluted regulatory scheme so that the market-
participant exception applies. See ante, at 14–19. This
needs little comment. It suffices to note that a “tax ex-
emption is not the sort of direct state involvement in the
market that falls within the market-participation doc-
trine.” Camps Newfound, 520 U. S., at 593. This expan-
sion of the market-participant exception, if it were
unleashed by a majority of the Court, would be an open
invitation to enact these kinds of discriminatory laws—
laws that, until today, the Court has not upheld in even a
single instance. Taxation is a quintessential act of regula-
tion, not market participation. See, e.g., New Energy, 486
U. S., at 278 (“[I]t [is] clear that Ohio’s assessment and
computation of its fuel sales tax, regardless of whether it
produces a subsidy, cannot plausibly be analogized to the
activity of a private purchaser”). And even in a case where
a State is a paradigmatic market participant because it
owns the asset itself, downstream restrictions that dis-
criminate against interstate commerce are not permitted.
See South-Central Timber Development, Inc. v. Wunnicke,
467 U. S. 82, 98 (1984) (plurality opinion) (“[A]lthough the
 Cite as: 553 U. S. ____ (2008) 15

KENNEDY, J., dissenting

State may be a participant in the timber market, it is
using its leverage in that market to exert a regula-
tory effect in the processing market, in which it is not a
participant”).
III
Throughout the Court’s argument is the concern that,
were this law to be invalidated, the national market for
bonds would be disrupted. See ante, at 23–27. The con-
cern is legitimate, but if it is to be the controlling rationale
the Court should cast its decision in those terms. The
Court could say there needs to be a sui generis exception,
noting that the interstate discrimination has been en-
trenched in many States and for a considerable time.
That rationale would prompt my own statement of dis-
agreement as a matter of principle and economic conse-
quences, but it would be preferable to a decision that
misinterprets the Court’s precedents. Instead, today the
Court weakens the preventative force of the Commerce
Clause and invites other protectionist laws, thus risking
further dislocations and market inefficiencies based on the
origin of products and commodities that should be traded
nationwide and without local trade barriers.
For these reasons, in my view, the judgment of the
Court of Appeals of Kentucky should be affirmed.
 Cite as: 553 U. S. ____ (2008) 1

ALITO, J., dissenting

SUPREME COURT OF THE UNITED STATES
_________________

No. 06–666
_________________

DEPARTMENT OF REVENUE OF KENTUCKY, ET AL.,
PETITIONERS v. GEORGE W. DAVIS ET UX.
ON WRIT OF CERTIORARI TO THE COURT OF APPEALS OF

KENTUCKY

[May 19, 2008]

JUSTICE ALITO, dissenting.
I proceed in this case, as I did in United Haulers Assn.,
Inc. v. Oneida-Herkimer Solid Waste Management Author-
ity, 550 U. S. ___, ___ (2007) (dissenting opinion), on the
assumption that the Court’s established dormant Com-
merce Clause precedents should be followed, and on that
assumption, I entirely agree with and join JUSTICE KEN-
NEDY’s dissent.