with whom
LOKEN, Chief Judge, and RILEY and GRUENDER, Circuit Judges, join, dissenting.In a series of cases beginning with United States v. Haack, 403 F.3d 997 (8th Cir.2005), United States v. Dalton, 404 F.3d 1029 (8th Cir.2005), and United States v. Pizano, 403 F.3d 991 (8th Cir.2005), this court was called upon to decide whether a district court, acting under 18 U.S.C. § 3553(e), abused its discretion by granting unreasonable sentence reductions below a statutory minimum term based on a defendant’s substantial assistance. These decisions, culminating in United States v. Burns, 500 F.3d 756 (8th Cir.2007) (en banc) (“Burns II”), vacated, — U.S. —, 128 S.Ct. 1091, 169 L.Ed.2d 804 (2008), developed a sound methodology for conducting appellate review of § 3553(e) reductions.
The Supreme Court’s decision in Gall v. United States, 552 U.S. 38, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007), concerning appellate review of sentencing decisions under a different statutory subsection, 18 U.S.C. § 3553(a), does not justify wholesale abandonment of the approach endorsed by the en banc court in Bums II. Gall implemented the constitutionally-based holding of United States v. Booker, 543 U.S. 220, 125 S.Ct. 738, 160 L.Ed.2d 621 (2005), which declared the sentencing guidelines effectively advisory in all cases, and established appellate review for “reasonableness.” But whereas the deferential appellate review under Gall and Booker must focus on whether a sentence is reasonable in light of all of the undifferentiated § 3553(a) factors taken as a whole, the sole purpose of appellate review in a § 3553(e) case is to determine whether the district court reduced a sentence below the statutory minimum “to an unreasonable degree” based on the defendant’s level of assistance. 18 U.S.C. § 3742(f)(2). Review of sentence reductions under § 3553(e), moreover, is unencumbered by the Sixth Amendment concerns that underlay Booker and Gall. Therefore, Gall does not dictate a dramatic change in our analysis of § 3553(e) cases, and substantially for the reasons discussed by the court in Bums II, I would reverse the judgment of the district court and remand for further proceedings.
I.
A.
Section 3553(e) provides:
*899Limited authority to impose a sentence below a statutory minimum.—
Upon motion of the Government, the court shall have the authority to impose a sentence below a level established by statute as a minimum sentence so as to reflect a defendant’s substantial assistance in the investigation or prosecution of another person who has committed an offense. Such sentence shall be imposed in accordance with the guidelines and policy statements issued by the Sentencing Commission pursuant to section 994 of title 28, United States Code.
The court today reaffirms that § 3553(e) grants limited authority for a district court to reduce a sentence based only on a defendant’s substantial assistance. A government motion under § 3553(e) does not authorize a sentencing court to impose a more lenient sentence based on the factors set forth in § 3553(a). See United States v. Williams, 474 F.3d 1130, 1130-31 (8th Cir.2007); see also United States v. Pearce, 191 F.3d 488, 494-95 (4th Cir.1999) (concluding that the district court improperly based its decision on factors unrelated to the defendant’s assistance to the government, as evidenced by the court’s permissive response to defense counsel’s argument invoking the “ ‘good ole days’ when judges did not have ‘to worry about guidelines and sentencing commissions and things like that’ ”); cf. Stephanos Bibas, Regulating Local Variations in Federal Sentencing, 58 Stan. L.Rev. 137,150 (2005) (“[Jjudges in some districts resent what they view as unduly severe Guidelines sentences. These judges are happy to exploit substantial assistance departures to escape the Guidelines’ strictures. Other judges, however, seek to peg their departures to the Guidelines, offering proportionate and more modest discounts.”) (footnote omitted).
Our decisions from Haack through Bums II established that a reduction under § 3553(e) based on substantial assistance should not be untethered from the structure of the sentencing guidelines, because the reductions take place in the context of a statutory plan that is designed to promote uniformity and proportionality in sentencing. We explained that the amount of the reduction should be proportional to the degree of assistance provided by the cooperating defendant. We observed that the guidelines provide for adjustments of two, three, and four offense levels to account for most aggravating and mitigating circumstances, United States v. Saenz, 428 F.3d 1159, 1162 (8th Cir.2005), and reasoned that when a court grants a reduction that substantially exceeds these benchmarks, it should identify exceptional facts to justify the larger reduction. See United States v. Jensen, 493 F.3d 997, 1001 (8th Cir.2007). In other words, a major reduction should be supported by a more significant justification than a minor one.
This methodology was well grounded in decisions of the Supreme Court and other circuits. In Williams v. United States, 503 U.S. 193, 112 S.Ct. 1112, 117 L.Ed.2d 341 (1992), the Court explained that a court of appeals should affirm a departure from an otherwise mandatory sentence if it is “satisfied that the departure is reasonable” under 18 U.S.C. § 3742(f)(2). Id. at 203, 112 S.Ct. 1112. “The reasonableness determination looks to the amount and extent of the departure in light of the grounds for departing.” Id. The reasons stated by the district court, therefore, must be “sufficient to justify the magnitude of the departure.” Id. at 204. Applying Williams in the context of substantial assistance, the Fourth Circuit in Pearce considered the nature, extent, and significance of a cooperating defendant’s assistance to the government, and found that it was insufficient to support the magnitude of the departure granted by the district court. 191 F.3d at 495. The Sev*900enth Circuit in United States v. Thomas, 930 F.2d 526 (7th Cir.1991), superseded on other grounds by USSG § 5H1.6 (1991), declared that substantial-assistance departures must be “linked to the structure of the guidelines.” Id. at 530. The court recognized that “weighing the impact of any given factor on the quality of the defendant’s cooperation is an imprecise art,” but cautioned that “ ‘departures of more than two levels should be explained with the care commensurate with their exceptional quality.’ ” Id. at 531 (quoting United States v. Ferro, 900 F.2d 1057, 1064 (7th Cir.1990)).
B.
Our cases under § 3553(e) before Gall carefully analyzed whether the district court’s stated reasons justified the magnitude of its reductions. In Haack, the court was left with the “firm impression that the district court reached outside its permissible range of choice and abused its discretion by departing downward to an unreasonable degree.” 403 F.3d at 1004 (internal quotation omitted). We reversed a seven-level reduction as unreasonably large, after observing that Haack’s cooperation consisted of providing information that led to the issuance of a search warrant at a residence, standing ready to testify against the occupants if needed, and providing information against suspects already under indictment or known to law enforcement. Id. at 1005. A reduction of that extent, the court explained, “leaves little room for greater departures for defendants who actually participate in controlled buys, wear wires, give grand jury and trial testimony, or are subjected to significant risk of injury or death to themselves or their family.” Id. at 1005-06. In Dalton, the court was left with “the definite and firm conviction” that the district court “exceeded the permissible bounds of its discretion,” 404 F.3d at 1034, when it granted a 12-level reduction to a defendant whose cooperation was “limited to proffering information about a handful of people and serving only as a corroborative witness before a grand jury against two of them.” Id. at 1033.
In Saenz, we held that the district court’s 11-level reduction was excessive and unreasonable, where the nature and extent of the defendant’s assistance was “relatively limited,” the significance and usefulness of her assistance was “relatively modest,” and she suffered no apparent danger or risk of injury. 428 F.3d at 1163-65. We also found unreasonable the district court’s conclusion that “any defendant who is timely, completely truthful, complete, reliable, and tells the government everything they need to know deserves more than 50 percent in reduction,” (ie., more than ten offense levels in the Saenz case), without regard to the nature and extent of the defendant’s assistance, the significance and usefulness of the assistance, or any danger or risk of injury endured by the cooperating defendant. Id. at 1162-63 (internal quotation omitted).
In United States v. Coyle, 429 F.3d 1192 (8th Cir.2005), we reversed as unreasonably large a 14-level reduction, which the district court characterized as “whopping,” id. at 1193 (internal quotation omitted), on the view that a reduction of that magnitude should be reserved for cooperating defendants who provide a greater degree of assistance. Id. at 1194. We observed that “[tjhere undoubtedly are defendants who provide long-term undercover assistance that is greater than the two controlled transactions involved here, who assist with the investigation of multimember conspiracies rather than the single defendant prosecuted in this matter, whose cooperation results in the apprehension of particularly dangerous offenders or ‘kingpins,’ and who suffer a more tangible risk of injury or actual harm as a result of their *901cooperation with the government.” Id. We were loathe to conclude that a defendant providing these greater levels of assistance must be awarded an even greater reduction (ie., 15 or more offense levels) to avoid unwarranted disparities. Id.
On the other hand, we affirmed as reasonable the district court’s 12-level reduction in Pizano, where the defendant provided timely and truthful cooperation, was a “key witness” against two co-conspirators, gave testimony that could be instrumental in seizing assets from a money laundering scheme, provided debriefings and grand jury testimony regarding both a close family member and a “major figure” in the conspiracy, and put himself and his family at risk of harm from “dangerous people” when he testified. 403 F.3d at 995-96. In United States v. Pepper, 486 F.3d 408 (8th Cir.2007) (“Pepper II”), after first remanding based on consideration of an improper factor, United States v. Pepper, 412 F.3d 995, 999 (8th Cir.2005) (“Pepper I”), we held that the district court did not abuse its discretion in reducing the defendant’s sentence by five offense levels based on “timely, truthful, honest, helpful, and important” assistance that the district court described as “pedestrian or average.” Pepper II, 486 F.3d at 411 (internal quotation omitted). In Jensen, we affirmed the district court’s six-level reduction for a defendant who was timely, complete, and truthful, was debriefed extensively by law enforcement agents concerning a substantial methamphetamine conspiracy, served as a prospective witness in a sentencing proceeding that ultimately was resolved by stipulation, identified a major figure in the drug conspiracy, and testified in the grand jury in support of a probable future indictment. 493 F.3d at 1001.
In Bums II, the en banc court applied the methodology developed in these cases and concluded that the district court’s ten-level reduction exceeded the bounds of reasonableness. 500 F.3d at 762. The court held that to affirm such a large reduction based on the assistance rendered by the defendant “would frustrate our goal of preventing departures from becoming untethered from the structure of the guidelines and would not reflect any meaningful sense of proportionality.” Id. at 766.
These decisions recognized that we could not say “with mathematical precision” how great a reduction should be granted for particular degrees of cooperation, Bums II, 500 F.3d at 762; Haack, 403 F.3d at 1005, but they identified ranges of reasonableness and outer limits on the district court’s exercise of discretion. The cases fostered a decisional process in which determinations about substantial-assistance reductions were linked to the structure of the guidelines, and were not motivated by improper factors such as hostility to mandatory sentencing, Haack, 403 F.3d at 1006, or a desire to sentence a defendant to “the shortest possible term of imprisonment” that would allow for participation in a prison drug treatment program. Pepper I, 412 F.3d at 999. The opinions strived to ensure that the magnitude of reductions were proportional to the circumstances that justified them, without micro-managing the district court’s sentencing decisions. As we said in Coyle, for example, “[t]here is a good deal of room between the government’s modest recommendation [for a reduction of less than two full offense levels] and the district court’s generous departure [of 14 levels] to recognize this defendant’s assistance without at the same time skewing the degree of reduction that must be granted to future defendants whose performance on the continuum of substantial assistance deserves more credit than Coyle’s.” 429 F.3d at 1194.
*902C.
During the same time period, this court began to implement the Supreme Court’s decision in Booker, which held that the application of the mandatory sentencing guidelines violated the Sixth Amendment right to jury trial in certain circumstances, and declared the guidelines “effectively advisory” in all cases as a remedy. 543 U.S. at 245, 125 S.Ct. 738. The Court held that sentencing courts should consider and take into account the sentencing guideline range, but that the district courts should impose sentence based on the factors set forth in 18 U.S.C. § 3553(a) as a whole. Id. Booker directed the courts of appeals to review sentences imposed by the district courts to determine whether they are “unreasonable with regard to § 3553(a).” Id. at 261.
Like some other circuits, our court interpreted Booker and its “reasonableness” requirement to call for what came to be described as “proportionality review” of sentences imposed under the new advisory regime. Under this approach, when a district court imposed a non-guideline sentence, we reviewed to determine whether the district court’s stated justification for varying from the advisory guidelines was “proportional to the extent of the difference between the advisory range and the sentence imposed.” United States v. Gall, 446 F.3d 884, 889 (8th Cir.2006) (internal quotations omitted), rev’d, 552 U.S. 38, 128 S.Ct. 586, 169 L.Ed.2d 445 (2007).
In Gall, the Supreme Court held that an appellate rule requiring a proportional justification for a variance from the advisory guideline range was impermissible for a specific reason: it was inconsistent with the remedial opinion in Booker. 128 S.Ct. at 595. The Court established that the proper measure of “reasonableness” in a § 3553(a) case is not whether the variance from the advisory guideline range is reasonable, but whether the ultimate sentence is reasonable in light of all of the § 3553(a) factors taken as a whole. Id. at 597. Proportionality review under § 3553(a), the Court explained, came “too close to creating an impermissible presumption of unreasonableness for sentences outside the Guidelines range.” Id. at 595. Because the advisory range is sometimes based on findings made by the sentencing judge, proportionality review would mean that some sentences would be “upheld only on the basis of additional judge-found facts,” id. at 602 (Scalia, J., concurring), and these sentences would violate the Sixth Amendment. See Rita v. United States, 551 U.S. 338, 371-72, 127 S.Ct. 2456, 168 L.Ed.2d 203 (2007) (Scalia, J., concurring in judgment). By rejecting proportionality review and applying a deferential abuse-ofdiseretion standard of review, the Court drastically curtailed review for substantive reasonableness, and thereby minimized the number of Sixth Amendment violations that will occur under the advisory system.
II.
A.
The Supreme Court remanded this case for further consideration in light of Gall.6 The analysis in Gall concerning review of a sentence imposed under § 3553(a), however, does not dictate that this court abandon *903its proportionality review of sentence reductions under § 3553(e). Booker has no application to § 3553(e). As the court reaffirms today, a sentencing judge is forbidden to rely on the § 3553(a) factors to reduce a sentence when acting on a government motion under § 3553(e). Ante, at 894. Unlike reasonableness review under § 3553(a), where the court of appeals is charged with considering the reasonableness of a sentence with regard to all of the factors in § 3553(a) taken as a whole, the exclusive purpose of reasonableness review under § 3553(e) is to determine whether the degree of the reduction from the statutory minimum sentence is reasonable. Gall held in the context of § 3553(a) that the court of appeals does not merely evaluate the reasonableness of a variance between the advisory guideline range and the final sentence. But the only responsibility of the court of appeals in a § 3553(e) case is to determine whether the departure below the statutory minimum is “to an unreasonable degree.” 18 U.S.C. § 3742(f)(2). There are no other factors at play.
The district court’s ruling on a substantial-assistance motion under § 3553(e) also poses no constitutional concerns under the Sixth Amendment. The only possible effect of a § 3553(e) motion is to reduce the defendant’s sentence. As with a sentence reduction proceeding under 18 U.S.C. § 3582(c), there is no potential that judicial factfinding conducted in resolving a § 3553(e) motion will increase the statutory maximum punishment. See United States v. Starks, 551 F.3d 839, 842 (8th Cir.), cert. denied, - U.S. -, 129 S.Ct. 2746, 174 L.Ed.2d 257 (2009). Accordingly, there is no constitutional difficulty with an appellate rule that requires a district court to identify justifications for a sentence reduction under § 3553(e) that are proportional to the magnitude of the reduction. The Court in Booker unanimously recognized that Congress in the Sentencing Reform Act sought to achieve uniformity in sentencing, and that the Booker remedy, with its wide discretion for sentencing judges, was contrary to what Congress desired. See Booker, 543 U.S. at 246-47, 250, 253, 263-64, 125 S.Ct. 738; id. at 292-300, 125 S.Ct. 738 (Stevens, J., dissenting); id. at 303-06, 125 S.Ct. 738 (Scalia, J., dissenting). With no Sixth Amendment concerns under § 3553(e), there is no reason to abandon a framework that is designed to keep sentence reductions tethered to the structure of the guideline system that Congress created.
Gall applied an abuse-of-discretion standard of review to a district court’s sentencing decisions, but this is nothing new. Well before Gall, in Koon v. United States, 518 U.S. 81, 96-100, 116 S.Ct. 2035, 135 L.Ed.2d 392 (1996), the Supreme Court applied an abuse of discretion standard to a district court’s departure from an otherwise mandatory sentence, and our § 3553(e) decisions from Haack to Bums II likewise conducted abuse of discretion review. See, e.g., Burns II, 500 F.3d at 760; Haack, 403 F.3d at 1003-04. Appellate review under this standard is not an “empty exercise,” and “[t]he deference that is due depends on the nature of the question presented.” Koon, 518 U.S. at 98,, 116 S.Ct. 2035. “ ‘Abuse of discretion’ may have different meanings in different contexts; the deference given a particular decision depends upon ‘the reason why that category or type of decision is committed to the trial court’s discretion in the first instance.’ ” Gasperini v. Ctr. for Humanities, Inc., 149 F.3d 137, 141 (2d Cir.1998) (quoting Henry J. Friendly, Indiscretion About Discretion, 31 Emory L.J. 747, 764 (1982)).
Under § 3553(a), due to a confluence of circumstances, a district court’s discretion is near its zenith. First, there is almost “no law to apply.” Friendly, supra, at 765. *904The district court has discretion to consider virtually unlimited information, see 18 U.S.C. § 3661; Williams v. New York, 337 U.S. 241, 247, 69 S.Ct. 1079, 93 L.Ed. 1337 (1949), and to apply the undifferentiated factors under § 3553(a) as it sees fit. After Gall and Kimbrough v. United States, 552 U.S. 85, 128 S.Ct. 558, 169 L.Ed.2d 481 (2007), this court has identified no basis in substantive law for a court of appeals to prefer one district court’s sentencing practices under § 3553(a) over those of another. See United States v. Feemster, 572 F.3d 455, 461-62 n. 4, 463-64 (8th Cir.2009) (en banc). As long as the sentencing judge does not act arbitrarily or shock the conscience, see Rita, 551 U.S. at 365, 127 S.Ct. 2456 (Stevens, J., concurring) (rejecting “purely procedural review,” because “[a]fter all, a district judge who gives harsh sentences to Yankees fans and lenient sentences to Red Sox fans would not be acting reasonably even if her procedural rulings were impeccable”), there seems to be no discernible legal reason for a court of appeals to declare unreasonable the decision of a judge who imposes sentence under § 3553(a) based on the individual characteristics and circumstances of a particular defendant.7 Second, the highly deferential standard of review adopted in Gall is influenced by the constitutional problems that would result from any more rigorous appellate review. Given that the basis for invalidating the mandatory guidelines in the first place was the Sixth Amendment, the standard of review adopted by the Court presumably is designed to ameliorate Sixth Amendment violations as much as possible, by giving the district courts free rein to apply the § 3553(a) factors. See Gall, 128 S.Ct. at 602 (Scalia, J., concurring). Third, the district court’s “institutional advantages” over the court of appeals are greatest when the sentencing court is engaged in a “unique study in ... human failings,” Gall, 128 S.Ct. at 598 (internal quotation omitted), informed by all of the factors set forth in § 3553(a), including even “insights not conveyed by the record.” Id. at 597.
In a § 3553(e) case, however, there is a “principle of preference” that is absent under § 3553(a). See Friendly, supra, at 768. It is entirely appropriate for a court of appeals to prefer a proportionate reduction from the mandatory minimum over a disproportionate one. The reasons given by the district court must be “sufficient to justify the magnitude of the departure,” Williams, 503 U.S. at 204, 112 S.Ct. 1112, and an evaluation of sufficiency requires the court of appeals to consider whether the magnitude of the assistance is proportional to the magnitude of the reduction. No constitutional difficulties arise from this rule of appellate review under § 3553(e). And the institutional advantages of the district court cited by the Court in Gall are muted. A sentence reduction under § 3553(e) does not involve the same wide-ranging, highly personal inquiry that a district court must undertake pursuant to § 3553(a). There is one discrete issue: the degree of reduction war*905ranted by the defendant’s assistance to the government. With respect to that decision, the governing policy statement of the Sentencing Commission establishes that the sentencing court owes deference to the institutional advantage of another party— the government, which sees more cooperating defendants than any single district judge, and which is best positioned to know the value of a defendant’s cooperation in law enforcement investigations. See USSG § 5Kl.l(a)(l) & comment, (n.3) (“Substantial weight should be given to the government’s evaluation of the extent of the defendant’s assistance, particularly where the extent and value of the assistance are difficult to ascertain.”). The court of appeals must ensure that the district court adheres to that principle of preference as well.
In discussing the standard of review in Gall, the Supreme Court concluded that the appellate review conducted by this court with respect to a decision under § 3553(a) “more closely resembled de novo review.” 128 S.Ct. at 600. It cannot fairly be said, however, that this court has applied the equivalent of de novo review to sentence reductions under § 3553(e). We affirmed a five-level reduction for “pedestrian” assistance in Pepper II, stating that it was a “close call,” but that we could not say the district court abused its discretion. 486 F.3d at 411 (internal quotation omitted). In Jensen, we rejected the government’s challenge to a six-level reduction, saying that while the reduction was “generous, and at or near the limit of what we could view as reasonable based on this level of assistance,” the district court did not abuse its discretion. 493 F.3d at 1001. And we affirmed a 12-level reduction in Pizano, saying that while the extent of the reduction was “well below the government’s recommendation,” it was not an abuse of discretion. 403 F.3d at 997. The discussion in these opinions does not suggest that the court of appeals reached agreement with the district court under a de novo standard of review. Rather, the court recognized that a range of discretion is available to the district court, and affirmed sentences even though “the appellate court might reasonably have concluded that a different sentence was appropriate.” Gall, 128 S.Ct. at 597. The mere fact that other sentence reductions under § 3553(e) were reversed as unreasonably large and an abuse of discretion does not mean that the court applied de novo review in those cases either.
B.
On this understanding of Gall, and of the distinctions between § 3553(a) and § 3553(e), the en banc decision in Bums II was essentially sound.8 We explained in Bums II that the district court justified its ten-level reduction by emphasizing the timeliness of Burns’s assistance, the truthfulness and completeness of his cooperation, and the nature and extent of the assistance. 500 F.3d at 763. We concluded, however, that the reasons given were *906not sufficient to justify the magnitude of the reduction in the context of a guideline system that typically employs adjustments of two, three, and four levels. Id. at 763-65.
We observed that the district court did not identify how Burns’s timeliness provided any discernible benefit. Id. at 764. We reasoned that the district court’s emphasis on Burns’s truthfulness and completeness, divorced from an assessment of the value of his assistance, did not justify treating Burns as an exceptional cooperator, particularly in view of the district court’s contemporaneous announcement in another case of a “bright-line rule” that “any defendant who is timely, completely truthful, complete, reliable, and tells the government everything they need to know deserves more than 50 percent” in reduction of sentence. Id. at 764 & n. 6; see Saenz, 428 F.3d at 1162-63. We determined that the district court applied an improper test regarding the “nature and extent” of assistance by focusing on whether the defendant “provided all of the information he knew,” Burns II, 500 F.3d at 759 (internal quotation omitted), because “the proper analysis under § 5Kl.l(a)(3) focuses on the nature and extent of the actual, discrete, and specific activities constituting the assistance, regardless of the opportunities available or the defendant’s willingness and ability to provide more.” Id. at 765.
At bottom, the Supreme Court’s decision in Gall regarding § 3553(a) does not undermine the conclusion of the panel dissent in United States v. Burns, 438 F.3d 826 (8th Cir.2006) (“Burns F), vacated and reh’g en banc granted, (8th Cir. May 18, 2006), adopted in substance by the en banc court in Burns II: “[Ejven after giving due respect to the carefully considered views of a district judge who has had the experience of sentencing untold defendants over the years, the [ten-level] reduction in this case was excessive in light of the relative insubstantiality of Burns’s assistance.” Burns I, 438 F.3d at 832 (Wollman, J., dissenting).9
III.
The en banc court charts a different course. It appears that so long as a sentencing court makes a § 3553(e) reduction that is not “capricious, whimsical, impressionistic, or ire-driven,” ante, at 896, it will be affirmed. No longer is there concern that a major reduction for a minor cooperator leaves little room to recognize assis*907tance from major cooperators, Haack, 403 F.3d at 1005-06, or that major reductions for minor cooperators deprive the system of “any meaningful sense of proportionality.” Burns II, 500 F.3d at 766.
The decision is a victory for Burns, but it will not necessarily benefit the class of cooperating defendants as a whole. Unlike sentencing under § 3553(a), where the district court is the sole actor and exercises what is now largely unconstrained discretion, reductions under § 3553(e) involve another actor. The United States Attorney, so long as he or she acts with no unconstitutional motive, retains sole discretion to determine whether a substantial-assistance motion should be filed under § 3553(e). Without such a motion, the court may not sentence below the statutory minimum.
The statute does not define what level of assistance counts as “substantial,” and the United States Attorney, in setting that bar, is entitled to make a “rational assessment of the cost and benefit that would flow from moving.” Wade v. United States, 504 U.S. 181, 187, 112 S.Ct. 1840, 118 L.Ed.2d 524 (1992). If a United States Attorney is not convinced that reductions under § 3553(e) for cooperators who provide relatively modest assistance will be correspondingly modest, then it would be rational for the United States Attorney to raise the bar, and withhold motions for some borderline cooperating defendants, until the sentencing court’s decisions demonstrate a satisfactory degree of proportionality. See Saenz, 428 F.3d at 1163. On the other hand, the United States Attorney may well find it necessary and proper to give the district court a better sense of how he or she evaluates various cooperators on the continuum of substantial assistance, with all parties cognizant that these matters cannot be defined with mathematical precision.
As Judge Wollman aptly put it in Bums I, “neither prosecutors nor district courts should yield to the temptation of indulging solipsistic preferences in recommending and imposing sentences.” 438 F.3d at 832 (Wollman, J., dissenting). “District judges after all are not minions of the prosecutor’s office. By the same token, United States Attorneys are not subalterns of the district court.” Id. The history of conflict between the United States Attorney and the district court in the § 3553(e) cases brought to this court is not encouraging, but perhaps the process set in motion by the en banc court’s elimination of meaningful appellate review will help to foster an equilibrium.
I respectfully dissent.
. The Court’s summary reconsideration order does "not amount to a final determination on the merits.” Henry v. City of Rock Hill, 376 U.S. 776, 777, 84 S.Ct. 1042, 12 L.Ed.2d 79 (1964) (per curiam). According to a leading treatise, “[i]t seems fairly clear that the Court does not treat the summary reconsideration order as the functional equivalent of a summary reversal order and that the lower court is being told merely to reconsider the entire case in light of the intervening precedent— which may or may not compel a different result.” Eugene Gressman, et al., Supreme Court Practice 349 (9th ed.2007).
. The Supreme Court has reserved judgment on whether “closer review may be in order when the sentencing judge varies from the Guidelines based solely on the judge's view that the Guidelines range 'fails properly to reflect § 3553(a) considerations’ even in a mine-run case.” Kimbrough v. United States, 552 U.S. 85, 128 S.Ct. 558, 575, 169 L.Ed.2d 481 (2007) (quoting Rita, 551 U.S. at 351, 127 S.Ct. 2456). The Court has not yet said, however, that a sentencing court is required to give any weight to the advisory guidelines. See id. at 576-77 (Scalia, J., concurring); Booker, 543 U.S. at 245, 264, 125 S.Ct. 738 (explaining that a district court must '-'consider” the advisory guidelines and “take them into account”); id. at 305-06, 125 S.Ct. 738 (Scalia, J., dissenting) (“If the majority ... thought the Guidelines not only had to be 'considered' ... but had generally to be followed ... its opinion would surely say so.”).
. Bums II did include some remnants of a mathematical percentage-based approach to evaluating reductions, which Gall rejected, 128 S.Ct. at 595-96, but those aspects of the opinion in Bums II do not affect the ultimate conclusion. Even before Gall, we had recognized the shortcomings of considering reductions in terms of percentages, and turned to a focus on offense levels as a method more in keeping with the structure and theory of the sentencing guidelines. Bums II, 500 F.3d at 762; Jensen, 493 F.3d at 1000-01; see also United States v. Chettiar, 501 F.3d 854, 860 (8th Cir.2007); United States v. Maloney, 466 F.3d 663, 668 (8th Cir.2006). Nothing in Gall suggests that reference to the Guidelines' sentencing table and the number of offense levels traversed by a reduction is an inappropriate means to distinguish a "major departure” from a "minor one.” Gall, 128 S.Ct. at 597.
. The statement in Gall that “all sentences” should be reviewed under a deferential abuse-of-discretion standard, ante, at 895 (quoting 128 S.Ct. at 591) (emphasis added by majority opinion), plainly refers to sentences imposed under § 3553(a) pursuant to the remedial opinion in Booker. See Gall, 128 S.Ct. at 594 ("Our explanation of 'reasonableness' review in the Booker opinion made it pellucidly clear that the familiar abuse-of-discretion standard of review now applies to appellate review of sentencing decisions.”). In any event, it is common ground that the reduction of Burns's sentence should be reviewed for abuse of discretion. The question here is whether abuse-of-discretion review of a reduction under § 3553(e) differs from review of a sentence imposed under § 3553(a), given the different purposes of appellate review and the absence of constitutional concerns under § 3553(e). The majority seems to believe that United States v. Livesay, 525 F.3d 1081 (11th Cir.2008), supports its approach, ante, at 894-95, but that case does not address the question presented in this appeal. Livesay had no occasion to apply the abuse-ofdiscretion standard to determine the reasonableness of a substantial-assistance reduction, because it reversed the district court for committing “procedural” error. 525 F.3d at 1092. Live-say also did not involve § 3553(e). When a court imposes sentence above the statutory minimum, as in Livesay, a defendant’s assistance is likely just another factor to be considered under § 3553(a), see United States v. Lazenby, 439 F.3d 928, 933-34 (8th Cir.2006), such that Gall is directly applicable.