dissenting:
I join in the majority’s conclusions in Parts I and 11(A) regarding our authority to review sentencing decisions as well as in Judge Straub’s and Sotomayor’s dissents insofar as they address the economic deterrence basis for the sentence imposed below. I also agree with Judge Sotoma-yor’s analysis of the closer standard of review that should be applied in this case. Because the majority does not rest its decision on the district’s court’s determination that a gun running offense is more serious when guns are transported to New York City, I take no position on that issue.
SOTOMAYOR, Circuit Judge, joined by Judge CARDAMONE and Judge STRAUB, concurs in part and dissents in part. Judge POOLER joins, in part, the dissent.1I join in the majority’s conclusions in Parts I and 11(A) regarding our authority *217to review sentencing decisions. But I dissent from the majority’s overly deferential review of the district court’s variance, on general policy grounds, from the Sentencing Guidelines; and I join in my colleague’s dissenting and concurring opinion. None of the district court’s stated reasons for its variance were adequately supported by objective criteria. Consequently, the sentence should be vacated and the case remanded.
As the majority recognizes, the Supreme Court has held that sentencing courts, in certain circumstances, are authorized to weigh generally applicable policy factors. Maj. Op. at 191 (citing Kimbrough v. United States, — U.S. -, 128 S.Ct. 558, 570, 169 L.Ed.2d 481 (2007)). The Supreme Court, however, has not suggested that this power is unfettered. To the contrary — and as acknowledged by the majority (Maj. Op. at 192 & n. 9) — the Supreme Court has distinguished different categories of cases to which varying degrees of appellate scrutiny apply. Kimbrough, 128 S.Ct. at 574-75. In the case before us, “closer review” is warranted because the district court “varie[d] from the Guidelines based solely on the judge’s view that the Guidelines range fail[ed] properly to reflect [18 U.S.C.] § 3558(a) considerations even in a mine-run case.” Id. at 575 (internal quotation marks omitted). The Supreme Court, however, did not elaborate on what it meant by “closer review,” and the majority opinion avoids fleshing out this standard. Although its contours remain imprecise, “closer review” must amount to more than the majority’s excessive deference to the district court’s decision, which risks a regression of the sentencing process to the “greatest deficiencies of the pre-Guidelines regime,” namely “its failure to provide for review of the decisions of sentencing judges and its failure to ensure that the sentencing judge’s exercise of discretion was informed by authoritative criteria and principles.” Kate Stith & José A. Cabranes, Judging Under the Federal Sentencing Guidelines, 91 Nw. U.L.Rev. 1247, 1253-54 (1997).2
Closer review is warranted where, as happened in this mine-run case, a district court implements a policy decision applicable to a wide class of offenders that is at odds with the Sentencing Commission. As the district court recognized, despite Congress’s direction to consider the “community view of the gravity of the offense,” 28 U.S.C. § 994(c)(4), “[t]he [Sentencing] Commission has, so far, never accepted the invitation to craft regional Guidelines,” at least with respect to the firearms trafficking at issue in this case. United States v. Lucania, 379 F.Supp.2d 288, 294 (E.D.N.Y.2005); see Reena Raggi, Local Concerns, Local Insights, 5 Fed. Sent’g Rep. 306, 306 (1993) (“When I voiced my concern to the Sentencing Commission about these guidelines for gun trafficking as they applied in New York, I was told that other parts of the country viewed gun crimes differently and that the guidelines *218were meant to reflect an average.”)- But the Sentencing Commission has deemed regional or population-based adjustments to be appropriate in other, limited circumstances.3 Thus, the Sentencing Commission’s decision not to differentiate firearms trafficking sentences based on the firearms’ destinations — despite a general invitation from Congress, a specific suggestion from at least one federal judge and the Sentencing Commission’s consideration of population and locale in another circumstance — suggests a deliberate “balance” between “the comparative virtues and vices of broad, simple categorization and detailed, complex subcategorization.” U.S. Sentencing Guidelines Manual Ch. 1 Part A.1.3.
Closer review is also appropriate because the judge’s sentence, in addition to being in tension with the Sentencing Commission, was not grounded in the district court’s “discrete institutional strengths.” Kimbrough, 128 S.Ct. at 574; see Maj. Op. at 191-92 (“[O]ur review must be informed by the discrete institutional strengths of the Sentencing Commission and the district courts.”) (internal quotation marks omitted). A sentencing judge’s expertise lies in his “greater familiarity with ... the individual case and the individual defendant before him than the [Sentencing] Commission or the appeals court.” Kimbrough, 128 S.Ct. at 574 (internal quotation marks omitted). The district court’s competence wanes as it moves from a case’s particularities evaluated through the framework of § 3553(a) to overarching considerations of criminal jurisprudence. For example, a district court is uniquely positioned to make a refined assessment of whether a crack/powder sentencing disparity is warranted because the court sentences both defendants accused of crack-related crimes as well as defendants accused of cocaine-related crimes. See Koon v. United States, 518 U.S. 81, 98, 116 S.Ct. 2035, 135 L.Ed.2d 392 (1996) (explaining that district courts have “an institutional advantage over appellate courts” in using their “day-to-day experience in criminal sentencing” to make a “comparison with the facts of other Guidelines cases”). But the district judge is not similarly well-situated to draw comparisons between defendants in different courts around the country: A judge in Brooklyn who is evaluating the relative dangers of gun trafficking throughout the nation enjoys no institutional advantage over appellate courts or the Sentencing Commission, if only because the judge’s experiences are limited to his or her region. A district court strays far from its expertise in varying from the Guidelines based on its disagreement with the Sentencing Commission— whose Congressionally mandated raison d’etre is “to formulate and constantly refine national sentencing standards,” Kim-brough, 128 S.Ct. at 574 — as to the proper national penal policy in response to regional differences relating to firearms trafficking.
*219In her concurrence, Judge Raggi argues that this case does not warrant closer review because the Sentencing Commission “has never considered whether the risk of harm posed by [firearms trafficking] crimes can vary depending on the intended destination for the guns.” Concurring Op. at 202. But the impact of almost any crime will vary according to its location. See, e.g., Vincent L. Broderick, Local Factors in Sentencing, 5 Fed. Sent’g Rep. 314, 314 (1993) (arguing that “the theft of a horse would have had entirely different significance in Montana and in Manhattan”). To argue that closer review is inappropriate unless the Sentencing Commission has explicitly disfavored a particular local consideration “in a Guideline or policy statement” (Concurring Op. at 203-04) ignores the uniformity at the heart of the Guidelines. See U.S. Sentencing Guidelines Manual Ch. 1 Part A.1.3 (“Congress sought reasonable uniformity in sentencing by narrowing the wide disparity in sentences imposed for similar criminal offenses committed by similar offenders.”). “Because one of the major purposes of the Guidelines was to eliminate unjustified disparities in sentences among similarly situated defendants,” we should consider the Sentencing Commission to have “adequately taken a circumstance into consideration” when, as in this case, the defendant’s offense “fits squarely within the language of the Guidelines” and the Sentencing Commission has made “conscious choices” regarding “the circumstances underlying the offense conduct.” United States v. Stultz, 356 F.3d 261, 266-67 (2d Cir.2004) (internal quotation marks and brackets omitted).
I believe that “closer review” means that we must test a district court’s application of broad policy factors in order to ensure that the district court’s conclusions can be objectively supported and are not based on faulty assumptions. This review does not amount to a policy debate. To the contrary, our review must focus on the district court’s articulated reasons and cited authority, evaluating whether the latter support the former. And despite Judge Rag-gi’s representation (Concurring Op. at 204 n. 10), such closer review does not mean that we substitute our own sentencing predilections for those of the district court. See Gall v. United States, — U.S.-,’ 128 S.Ct. 586, 600, 169 L.Ed.2d 445 (2007) (criticizing appellate court’s usurpation of district court’s fact-finding role). It does, however, mean that district courts cannot immunize their decisions from appellate review by talismanic invocations to local “experience” and “a sort of judicial common sense.” See Concurring Op. of J. Raggi at 205-06. For example, in Kim-brough, the district court did not rest its policy variance from the Guidelines solely upon its own courtroom experiences or legal hypotheses; instead it referenced the Sentencing Commission’s extensive research and reports criticizing the crack/powder disparity. See 128 S.Ct. at 568, 575.4 To suggest that appellate courts should affirm a sentencing rationale if it is plausible under any set of assumptions reduces the Guidelines and appellate courts to what they are clearly not: “a body of casual advice, to be consulted or overlooked at the whim of a sentencing *220judge.” United States v. Crosby, 397 F.3d 103, 113 (2d Cir.2005).
As the district court recognized in this case, arbitrary and subjective considerations, such as a judge’s feelings about a particular type of crime, should not form the basis of a sentence. Lucania, 379 F.Supp.2d at 296. The majority and I agree. Maj. Op. at 194-95; cf. Charles P. Sifton, Theme and Variations: The Relationship Between National Sentencing Standards and Local Conditions, 5 Fed. Sent’g Rep. 303, 303 (1993) (arguing that a sentence would create unwarranted disparity if it were motivated by “an effort to set aside national norms on the basis of local concerns without examining either the factual or legal significance of those concerns”). Yet a serious danger exists that sentencing judges will dress their subjective views in objective trappings, either by using questionable empirical data or by invoking a “common sense” at odds with reality. We only encourage this confusion if we signal that our review of sentencing decisions is cursory.
I do not suggest that the thoughtful and respected district judge in this case sentenced according to a caprice. His detailed opinion and its careful discussion of the § 3553(a) factors demonstrate otherwise. The dialogue between trial and appellate courts depends upon the candor of all judges, and the district court here is to be commended for its thorough explanation of its sentencing decision. Nevertheless, the district court’s analysis and data are insufficient to support its conclusion that defendant-appellant deserved a severer sentence because firearms trafficking (1) is a more serious crime in densely populated areas, and (2) requires greater deterrence in areas with restrictive gun laws. For that reason, I believe that the enhanced sentence that the district court imposed on defendant-appellant should be vacated and remanded for reconsideration by the district court.
With respect to the seriousness of the offense, the district court relied on data compiled by the Department of Justice, which indicated that “homicide rates in large urban areas remain substantially higher than in suburban and rural areas.” Lucania, 379 F.Supp.2d at 295 (citing U.S. Dep’t of Justice, Office of Justice Programs, Bureau of Justice Statistics, Homicide Trends in the U.S., Trends by City Size, http://www.ojp.usdoj.gov/bjs/ homicide/city.htm). Yet the data say nothing about the homicide rate in New York City, and they do not show that a gun in New York City is more likely to hurt people than a gun elsewhere. More generally, the data do not demonstrate that homicide rates increase as population density increases because they do not consider the population density of a city, but only the total population. To the extent that the data are relevant, a district court could conclude that gun trafficking into more populated cities is less dangerous than gun trafficking elsewhere because the data demonstrate that over the last five years covered by the report (2001-2005), the average homicide rate in cities with populations between 250K-499K was approximately 10% higher than the homicide rate in the largest cities. See U.S. Dep’t of Justice, Office of Justice Programs, Bureau of Justice Statistics, Homicide Trends in the U.S., Homicide Victimization Rate, http://www.ojp.usdoj. gov/bjs/homicide/tables/vcitytab.htm (last visited November 19, 2008) (“DOJ Homicide Statistics”).5 The same data could *221support either a harsher or a more lenient sentence, and some of my colleagues’ reasoning suggests that this Court would be required to affirm either outcome. See Concurring Op. of J. Raggi at 201 (arguing that there was no procedural error where the district court “modestly considered the seriousness of [defendant-appellant]’s crime by reference to the community for which the illegal guns were intended”). Although district courts need not always rely upon empirical data when varying from the Guidelines, a sentence should not be sustained when the data cited by a district court undermine its own conclusions.
The district court implied that common sense dictates that a gun is more dangerous in more densely populated areas because of the higher likelihood that random bystanders might be shot. Lucania, 379 F.Supp.2d at 296. But the district court erred in not scrutinizing more closely its “common sense” assumptions. Even if true that there is a slightly higher statistical probability that a gun will cause harm to a bystander in a densely populated area, it does not necessarily mean that the incremental increase in dangerousness is worthy of an increase in the sentence imposed. Moreover, the “vast majority” of homicide victims in New York City last year were not strangers to their assailants. A1 Baker, City Homicides Still Dropping, to Under 500, N.Y. Times, Nov. 23, 2007, at A1 (concluding that “[t]he low number of killings by strangers belies the common imagery that New Yorkers are vulnerable to arbitrary attacks on the streets, or die in robberies that turn fatal”). This means that defendant-appellant received an increase in his sentence based on mere speculation that one of the guns he sold might have harmed a bystander in New York City, and that this harm would not have happened if he had sold the guns in a less densely populated area. The district court did not sufficiently analyze whether the risk of harm to bystanders in New York City justified a more severe sentence for defendant-appellant. See United States v. Anati, 457 F.3d 233, 238 (2d Cir.2006) (noting, in dicta, that to the extent that “the special impact of [an] offense in a particular geographic community might be relevant, there might have to be some empirical basis for deeming the impact of a heroin offense in a particular community more serious than the assessment made by the Sentencing Commission.” (emphasis added)), overruled in part on other grounds by Irizarry v. United States, — U.S. -- & n. 1, 128 S.Ct. 2198, 2201-02 & n. 1, 171 L.Ed.2d 28 (2008). Instead, it simply assumed that these weapons posed a greater danger in *222New York City than elsewhere because of population density.6
The district court’s other rationale for imposing a non-Guidelines sentence was based on “general deterrence.” The majority affirms the district court’s sentence on this basis (Maj. Op. at 195-97), even though the district court’s reasoning was unsubstantiated and unconvincing. In concluding that firearms trafficking is more profitable in New York City than in less tightly regulated areas, the sentencing judge’s sole support was a law review article that hypothesized — without the benefit of data — that “there may well be unusual areas, such as New York City, Washington, D.C., or Boston, where the supply of legally owned guns and stolen guns circulating among criminals is low enough to leave room for criminal entrepreneurs to make a living selling guns illegally.” Gary Kleck, BATF Gun Trace Data and the Role of Organized Gun Trafficking in Supplying Guns to Criminals, 18 St. Louis Univ. Pub.L.Rev. 23, 41 (1999). The district judge did not make any finding as to where the majority of firearms trafficking offenses occur, and he assumed that the firearms trafficking offenses which make up the Guidelines’ “national average” are spread evenly throughout the country rather than clumped in certain areas. But if the article cited by the district court is correct that the black market for guns is only profitable in a few areas like New York, Washington, D.C. and Boston, then it may well be that firearms trafficking crimes occur almost entirely or predominantly in those areas, in which case the Guidelines may already account for any deterrence issues raised by New York’s strict gun laws. If so, defendant-appellant’s sentence would have been needlessly increased.
The majority states that firearms trafficking is more profitable in areas with strict gun laws because more regulation increases the costs of obtaining a gun. And “[wjhere the profits to be made from violating a law are higher, the penalty needs to be correspondingly higher to achieve the same amount of deterrence.” Maj. Op. at 196.7 The majority commits a *223fundamental error by attempting to bolster the sentencing judge’s argument by relying upon articles and economic theories never referenced by the district court. This shifts the appellate court’s role from reviewing the lower court’s sentencing rationale to crafting it. Even assuming that the majority’s general deterrence rationale were correct, defendant-appellant’s case is a particularly poor application. Defendant-appellant sold his guns in Florida, and nothing in the record indicates that he profited more on his sales to New York than on his sales to other destinations.
There are additional reasons to be skeptical and wary of the district court’s theory of general deterrence. First, it is unrealistic to believe that gun traffickers willing to risk up to twenty-five years under New York law (N.Y. Penal Law §§ 70.02, 265.13 (McKinney 2008)) will now be more deterred by the possibility that, if they are charged in federal court, a federal sentencing judge in New York may increase their sentence based on the gun destination. Second, determinations regarding general deterrence may be highly subjective, and we must be careful that the individual defendant is not lost in a stereotype. If we accept the unsubstantiated general deterrence theory here, then we open the door to sentencing increases or decreases based on a litany of socio-economic factors that some study shows are linked with an increased or decreased likelihood of committing a particular crime. Finally, deterrence assumes that potential violators can anticipate what punishment they might receive. To the extent that consequences for the same federal offense vary widely from one judge to the next, deterrence is undermined because “a defendant who comes up for sentencing has no way of knowing or reliably predicting whether he will walk out of the courtroom on probation, or be locked up for a term of years that may consume the rest of his life, or something in between.” Marvin E. Frankel, Criminal Sentences: Law Without Order 6 (1973); see U.S. Sentencing Guidelines Manual Ch. 1 Part A.1.3 (“A sentencing system tailored to fit every conceivable wrinkle of each case would quickly become unworkable and seriously compromise the certainty of punishment and its deterrent effect.”).
Even if I were to find adequate the district court’s deterrence-based rationale for varying from the Guidelines, I still would not affirm the district court’s judgment. The majority held that it need not consider the district court’s argument that firearms create a greater risk of harm in more densely populated areas because the sentencing judge’s deterrence rationale provided “an independently sufficient justification for its variation from the Guidelines.” Maj. Op. at 195-96. But nothing in the record demonstrates that the district court would have increased the sentence to the same extent based solely on the deterrence rationale. We should not encourage district courts to compile catalogs of possible justifications for their sentences in the hope that appellate courts will sift the wheat from the chaff in pursuit of a valid reason to affirm.
*224I believe that district courts should be extremely careful, if not reticent, about imposing generic policy preferences on individual defendants. I do not, however, exclude the possibility that there may exist local conditions that may warrant a variance from the Guidelines if the conditions are significant and have not already been factored into the Guidelines. Our criminal justice system benefits when district courts and the Sentencing Commission engage in an “iterative process” whose outcome minimizes unwarranted sentencing disparities while appreciating individual nuances. See Tr. of Oral Arg. at 39, Gall v. United States, — U.S.-, 128 S.Ct. 586, 169 L.Ed.2d 445 (Breyer, J.) (“What we want ... is to interpret that word ‘reasonable’ so that we get back to a situation where judges do depart when they have something unusual and maybe occasionally when they think the guideline wasn’t considered properly, and then the iterative process takes over, going back to the commission. Now, how do we get there?”). But the majority’s approach risks easting aside the Guidelines instead of enhancing their value.
Appellate courts must not abdicate their responsibility to ensure that sentences are based on sound judgment, lest we return to the “shameful” lack of parity, S.Rep. No. 98-225, at 65 (1983), as reprinted in 1984 U.S.C.C.A.N. 3182, 3248, which the Guidelines sought to remedy. Gut feelings about regional differences can be subjective in dangerous ways. Empirical data should be scrutinized because they make subjective feelings appear plausible, even when the analysis suffers from significant flaws. We should therefore have vacated the sentence and' remanded this case to the district court for reconsideration.
. The result of these failures was evident in a Second-Circuit study conducted prior to the Guidelines, in which trial judges were asked to sentence hypothetical offenders using identical presentence reports. Anthony Partridge & William B. Eldridge, The Second Circuit Sentencing Study: A Report to the Judges of the Second Circuit 1-3 (1974). The disparities were vast. Punishments for a bank robber ranged from five to eighteen years in prison. Id. at A-9. A seller of heroin was incarcerated from one to ten years depending on the judge. Id. at A-ll. The study concluded that the sentencing pattern displayed in this Circuit was "not one of substantial consensus with a few sentences falling outside the area of agreement. Rather, it would appear that absence of consensus is the norm.” Id. at 9.
. See, e.g., U.S. Sentencing Guidelines Manual § 2H4.1(b)(4) & cmt. n. 2 (defining "any other felony offense” with reference to "federal, state, or local law”); id. § 2K2.1(b)(2) & cmt. n. 6 (allowing for reduction in offense level if firearms were possessed solely for lawful sporting or collecting purposes, depending upon, inter alia, "the extent to which possession was restricted by local law”); of. U.S.S.C. Public Hearing Panel V, United States Sentencing Commission (Mar. 15, 2006) (Statement of John Rhodes, Federal Defenders of Montana), available at http://www.ussc. gov/hearmgs/03_15_06/0315USSC.pdf (opposing proposed Guidelines enhancement for firearms trafficking based on existence of "unlawful scheme” because "what’s an unlawful scheme in the District of Columbia may not be an unlawful scheme in Montana. So [under the proposed enhancement] ... you're going to run into the problem of reading regional disparity”).
. Likewise, in this case, when the district court varied from the Guidelines because of defendant-appellant’s advanced age and the “inverse relationship between age and recidivism,” the district court cited numerous cases, many of which, in turn, relied upon a recidivism study of over 6,000 individuals that was conducted in 2004 by the Sentencing Commission. Lucania, 379 F.Supp.2d at 297-98 (citing, inter alia, United States v. Eberhard, 2005 WL 1384038, at *10 (S.D.N.Y. June 9, 2005)) (citing United States Sentencing Commission, Measuring Recidivism: The Criminal History Computation of the Federal Sentencing Guidelines (2004)).
. The statistics cited by the district court indicate that, in 2005 (when defendant-appellant was sentenced (Maj. Op. at 185)), the homicide rates per 100,000 people were as follows:
Population: One Million + 500K-999K 250K-499K 100K-249K
*221 Homicide Rate: 13.0 14.8 15.2 10.1
DOJ Homicide Statistics. These data indicate that, in 2005, the homicide rate for cities with populations of 250K-499K was approximately 17% greater than the homicide rate of the largest cities. Furthermore, it is noteworthy that New Orleans and Gary, Indiana, which did not even rank among the 30 most densely populated American cities (based on population per square mile) according to the resource relied upon by the district court, have had the highest homicide rates in the country. See National League of Cities, 30 Most Densely Populated Cities, http://www.nlc.org/abouL.cities/cities_101/187.aspx (last visited November 8, 2008); Rick Jervis, “New Orleans Homicides up 30% Over 2006 Level: City on Track to Retain Most-Murderous Label,” USA Today, Jan. 3, 2008. Yet, following Judge Raggi's reasoning (Concurring Op. at 208-09), a sentencing judge would be correct to infer a heightened risk of harm from firearms trafficking in a more densely populated but safer American city. But see Hanna Rosin, "American Murder Mystery,” The Atlantic, July/Aug.2008, available at http://www.theatlantic.com/doc/200807/memphis-crime (exploring why "America’s most dangerous spots” now include cities such as "Florence, South Carolina; Charlotte-Mecklenburg, North Carolina; Kansas City, Missouri; Reading, Pennsylvania; Orlando, Florida; [and] Memphis, Tennessee").
. In her concurrence, Judge Raggi cites several newspaper articles not relied upon by the district court as evidence of "the significant number of New Yorkers, many of them children, who are regularly injured by random gunfire.” Concurring Op. at 207. This parade of horribles is not limited to New York City. See, e.g., Jon Gambrell, "Curfew Widened in Crime-Ridden Arkansas Town,” Houston Chronicle, Aug. 17, 2008, at A8 (describing residents of Helena-West Helena sleeping on floors of their houses out of fear of stray bullets). In addition, a brief review of headlines from the city of New Orleans during the last eighteen months uncovered numerous articles describing victims of stray bullets, including the following:
— "New Orleans Police Blotter,” New Orleans Times-Picayune, Oct. 9, 2008, at 3 (“A 17-year-old girl was hit in the leg by one or more stray bullets fired by a stranger.”).
— Katy Reckdahl, "Woman with Gun Terrorizes Children,” New Orleans Times-Picayune, July 17, 2008, at 1.
— Maty Sparacello, "Housing Authority Reining in Parties: Kenner Shooting Leads to Regulations,” New Orleans Times-Picayune, Oct. 11, 2007, at 1 ("Three children, 7, 8 and 13, were struck by stray bullets” at birthday party for five-year-old twins.).
— Walt Philbin, "Man Carrying Baby Hit by Stray Bullets in Drive-By,” New Orleans Times-Picayune, July 14, 2007, at 1.
. The majority oversimplifies the economic incentives faced by firearms traffickers. In discussing deterrence, the majority focuses only on the severity of the penalty. But the expected cost of firearms trafficking is a function of both the sanction's magnitude and the probability of getting caught. See Richard A. Posner, Economic Analysis of the Law, § 7.2 (7th ed. 2007) ("An expected punishment cost of $1,000 can be imposed by combining a fine of $1,000 with a probability of apprehension and conviction of 1....”). In areas with strict local gun laws, firearms traffickers may face a greater risk of apprehension than in *223more lax regimes. The majority seems to acknowledge this point when it later asserts that "stringent local gun regulations create a higher barrier to entry” for firearms traffickers. Maj. Op. at 196 n. 14; see Concurring Op. of J. Raggi at 209 (noting New York City’s "decade-long commitment of increased police resources to removing illegal guns from the street”). Accordingly, even without increasing the sanctions on gun trafficking, the expected cost for this offense may be sufficiently elevated in more tightly regulated markets so as to achieve the same amount of deterrence present in more lax regimes. Regardless, the speculative nature of these arguments only emphasizes the need for data, an ounce of which would be worth a ton of theory.