This Article provides the first empirical study of the Roberts Court’s use of substantive canons in statutory interpretation cases. Based on data from 296 cases, the Article argues that much of the conventional wisdom about substantive canons of statutory construction is wrong, or at least overstated with respect to the modern Supreme Court. Substantive canons—for example, the rule of lenity, the avoidance canon, and the presumption against extraterritorial application of domestic laws—have long been criticized as undemocratic judge-made rules that defeat congressional intent, enable interpreters to massage different meanings out of the same text, and make statutory interpretation unpredictable. Scholars have bemoaned the amount of work that substantive canons perform in statutory interpretation cases, and several have charged that textualist judges in particular overuse such canons. But virtually all of these critiques have occurred in the absence of empirical evidence about how judges invoke substantive canons in practice.

This Article reconsiders the substantive canons in light of new data collected from the Roberts Court. The data show that, contrary to the conventional wisdom, substantive canons are infrequently invoked on the modern Court—and even when invoked, they rarely play an outcome-determinative role in the Court’s statutory constructions. Perhaps most surprisingly, textualist justices—including Justice Antonin Scalia—rarely invoke substantive canons in the opinions they author, and do so less often than most of their purposivist counterparts. Moreover, contrary to the conventional view that substantive canons empower judges to read their personal policy preferences into statutes, the Court’s conservative justices have employed substantive canons to support liberal case outcomes as often, or nearly as often, as they have employed such canons to support conservative outcomes. Further, doctrinal analysis shows that the Roberts Court repeatedly has used substantive canons to honor, rather than frustrate, congressional intent.

The Article also challenges scholars’ gloomy warnings that justices in the modern, textualism-influenced era have replaced legislative history with substantive canons as the go-to resource for deciphering ambiguous statutory text. Rather, the data from the Roberts Court show that most of the justices referenced legislative history at higher rates than they referenced substantive canons. More­over, the Court’s own precedents—rather than substantive canons or legislative history—seem to be the unsung gap-filling mechanism that the justices turn to when confronted with unclear statutory text. After reporting the data, the Article discusses the implications of its findings for current debates in statutory interpretation, arguing that statutory interpretation theory needs to pay less attention to substantive canons and more attention to how the Court employs precedents when construing statutes.


There is a popular belief among statutory interpretation scholars that substantive canons of statutory construction—that is, policy-based background norms or presumptions such as the rule of lenity and the canon of constitutional avoidance—act as an “escape valve” that helps textualist judges eschew, or “mitigate,” the rigors of textualism.1 As Professor William Eskridge has noted, “[T]he textualist who refuses to consider legislative history will be sorely tempted to rely on [substantive canons] to provide necessary context and analysis for deciding issues of interpretation.”2 The conventional wisdom is that substantive canons operate as an interpretive trump card, allowing judges to reject statutory readings dictated by other tools of construction in favor of readings based on external policy considerations.3 In the conventional telling, substantive canons are thought to wield significant power—indeed, too much power—over interpretive outcomes.

Scholars on both sides of the textualist-purposivist divide have criticized substantive canons, although textualists also have defended some substantive canons as entrenched background conventions that Congress is aware of when it legislates.4 Justice Antonin Scalia, notably, decried substantive canons as “dice-loading” devices;5 but he, in turn, has been accused of employing such canons generously when it suited his ends.6 Scholars have pointed out that substantive canons are countermajoritarian, subject to judicial invention and reinvention, and difficult for Congress to overcome.7 Recent work has characterized substantive canons as the equivalent of federal common law, explored the theoretical tension between textualism and the substantive canons, and concluded that the constitutionally based canons, at least, are defensible on a “faithful agent” theory of statutory interpretation.8

Virtually all of this theorizing has occurred in the absence of empirical evidence about how often judges invoke substantive canons or how much work such canons perform in statutory cases when invoked. There is a general consensus that the avoidance canon has been much abused9 and that the rule of lenity has fallen into disuse,10 but no one has examined the federal courts’ use of substantive canons systematically. Instead, based on anecdote and speculation, much of it fueled by the Rehnquist Court’s creation of several federalism clear statement rules in the 1980s and 1990s or the Roberts Court’s use of the avoidance canon in recent high-profile cases,11 scholars have taken for granted that substantive canons play a regular, decisive role in the judicial interpretation of statutes—and that textualism needs to articulate a justification for its subscribers’ frequent use of such canons. But what if it turns out that these scholarly assumptions are wrong—or at least overstated—in several important respects?

This Article provides the first empirical study of the Roberts Court’s use of substantive canons in its statutory interpretation cases. Based on data from 296 statutory interpretation cases decided by the Roberts Court during its first six and a half terms, the Article reports several surprising findings that call into doubt the conventional account of substantive canons and, particularly, their relationship to textualism. Five points stand out: (1) contrary to popular claims that textualist judges rely on substantive canons frequently, the Court’s textualist justices rarely invoked substantive canons in the opinions they authored (11.0 percent and 11.7 percent for Scalia and Justice Clarence Thomas, respectively), and did so no more often than their nontextualist counterparts;12 (2) despite the ubiquity of substantive canons and charges that judges regularly invent new ones, only a handful of substantive canons appear to be doing meaningful work on the modern Court;13 (3) a majority of the Roberts Court’s references to substantive canons have been in passing, as makeweight or secondary arguments, with only a small number of cases relying significantly on such canons; (4) when the Court did rely significantly on substantive canons, it often exhibited more attentiveness to Congress’s intent than the conventional view of substantive canons accounts for; and (5) contrary to the popular belief that substantive canons empower judges to decide cases based on their personal policy preferences, the Court’s conservative justices invoked substantive canons to support liberal outcomes nearly as often, and in some cases more often, than they invoked such canons to support conservative outcomes.

These findings have important theoretical implications. For example, they raise the question: If textualist judges are not relying on substantive canons to mitigate the rigors of textualism, then what interpretive tools are they using to serve that function? Data from textualist-authored opinions in which substantive canons were not used suggest that the answer to this question is Supreme Court precedent and, to some extent, practical-consequences-based reasoning.14 The findings also suggest that some of the criticisms leveled against substantive canons may be overstated—for example, substantive canons may be less prone to invention and reinvention than previously thought. Indeed, in six and a half terms, I counted only four instances in which the members of the Roberts Court invoked an arguably “new” substantive canon—and over half of the Court’s substantive canon references involved one of just six well-established canons.15 This means that despite the wide array of substantive canons created over the past two centuries, the Roberts Court was remarkably constrained, and somewhat predictable, in the canons it tended to invoke. The data also suggest that substantive canons may be applied in a manner that is more supportive of congressional intent than the conventional account recognizes.16 Doctrinal analy­sis of the handful of cases in the data set in which the Court did rely significantly on substantive canons reveals that, in several instances, the Court used the avoidance canon to read a statute in a manner that honored a recent congressional override, or to preserve a long-standing statute against constitutional challenge.17 In other cases, the Court employed substantive canons in tandem with, or as an approximation of, congressional intent.18 These cases stand in marked contrast to the conventional wisdom—including recent commentary about the Roberts Court19—arguing that the Court uses substantive canons to displace legislative preferences with judicial ones.

Further, the data from this study suggest that, in practice, there may not be the stark textualist-purposivist divide that scholars have described regarding whether to consult substantive canons or legislative history to provide contextual clues about statutory meaning.20 As Part II describes in detail, eight of the eleven justices who have served on the Roberts Court for a significant amount of time have referenced legislative history at higher rates—sometimes much higher rates—than they have referenced substantive canons. Even archtextualist Scalia invoked substantive canons at almost the same rate as he invoked legislative history—an interpretive resource he considered illegitimate—and Thomas referenced both of these tools at quite low rates, suggesting a miserly view of both.21 In addition, the data on levels of reliance provide some support for pragmatists’ contentions that the canons of construction do not play much of a role in the judicial interpretation of statutes, and that judges use them as mere “window-dressing” to shore up interpretations reached primarily through other tools.22

Finally, taken as a whole, the data suggest that the Roberts Court’s treatment of substantive canons correlates surprisingly well with the methodological stare decisis employed by several state courts—which place substantive canons last in the hierarchy of statutory construction tools23—and with the rules of statutory construction codified by many state legislatures, which list only a handful of substantive canons among the rules they instruct state courts to follow.24 The Roberts Court’s limited use of substantive canons also seems to accord with the preferences of congressional staffers in charge of drafting legislation, who rank substantive canons behind legislative history and rules on agency deference when asked about the usefulness of particular interpretive aids.25

This Article proceeds in three parts. Part I describes the conventional understanding of substantive canons. Part II reports the findings from my study of the Roberts Court’s substantive canon use from January 2006, when Justice Samuel Alito joined the Court, to the end of the Court’s 2011 term. It also provides doctrinal analysis of several cases in which the Court relied significantly on substantive canons, and examines the tools the Court invoked when it did not reference substantive canons. Part III explores the theoretical implications of the data and doctrinal observations.

  • 1. John F. Manning, Textualism and the Equity of the Statute, 101 Colum L Rev 1, 125 (2001). See also William N. Eskridge Jr, et al, Cases and Materials on Legislation and Regulation: Statutes and the Creation of Public Policy 743 (West Academic 5th ed 2014) (“Critics could suggest that . . . every human interpretive technique, including textualism, needs a ‘safety valve’ of some sort.”).
  • 2. William N. Eskridge Jr, Book Review, Textualism, the Unknown Ideal?, 96 Mich L Rev 1509, 1542 (1998), reviewing Antonin Scalia, A Matter of Interpretation: Federal Courts and the Law (Princeton 1997) (Amy Gutmann, ed).
  • 3. See, for example, Amy Coney Barrett, Substantive Canons and Faithful Agency, 90 BU L Rev 109, 109–10 (2010); Eskridge, Book Review, 96 Mich L Rev at 1545–46 (cited in note 2).
  • 4. See Manning, 101 Colum L Rev at 125 (cited in note 1); Scalia, A Matter of Interpretation at 29 (cited in note 2) (defending the rule of lenity and rules requiring a clear statement to eliminate state sovereignty or to waive the federal government’s sovereign immunity).
  • 5. Scalia, A Matter of Interpretation at 28 (cited in note 2).
  • 6. See, for example, Eskridge, Book Review, 96 Mich L Rev at 1512 n 9 (cited in note 2) (“Scalia warns that ‘to the honest textualist, all of these preferential rules and presumptions are a lot of trouble,’ and criticizes the substantive canons. Yet Scalia himself not only cites but heavily relies on these ‘substantive’ canons.”) (brackets and citations omitted); id at 1543–46 (discussing Scalia’s use of a substantive canon in BFP v Resolution Trust Corp, 511 US 531 (1994)); Bradford C. Mank, Textualism’s Selective Canons of Statutory Construction: Reinvigorating Individual Liberties, Legislative Authority, and Deference to Executive Agencies, 86 Ky L J 527, 551 (1997–98) (“Justice Scalia and other modern textualists often use ‘clear-statement canons’ that require express congressional authorization for a particular type of government regulatory action.”).
  • 7. See, for example, Neal Kumar Katyal and Thomas P. Schmidt, Active Avoidance: The Modern Supreme Court and Legal Change, 128 Harv L Rev 2109, 2119 (2015); William N. Eskridge Jr and Philip P. Frickey, Quasi-Constitutional Law: Clear Statement Rules as Constitutional Lawmaking, 45 Vand L Rev 593, 636–40 (1992); Eskridge, Book Review, 96 Mich L Rev at 1542–43 (cited in note 2); William N. Eskridge Jr, The New Textualism, 37 UCLA L Rev 621, 683–84 (1990).
  • 8. See Abbe R. Gluck, The Federal Common Law of Statutory Interpretation: Erie for the Age of Statutes, 54 Wm & Mary L Rev 753, 778–79 (2013) (theorizing that at least some of the canons might be viewed as a kind of federal common law); Barrett, 90 BU L Rev at 169 (cited in note 3) (suggesting that judges act as “faithful agents of the Constitution” when they apply constitutionally based substantive canons).
  • 9. See, for example, Katyal and Schmidt, 128 Harv L Rev at 2129–53 (cited in note 7) (discussing and critiquing the use of the avoidance canon in several recent Supreme Court cases); Jerry L. Mashaw, Greed, Chaos, and Governance: Using Public Choice to Improve Public Law 105 (Yale 1997) (describing the avoidance canon as suboptimal given game theory analysis); William K. Kelley, Avoiding Constitutional Questions as a Three-Branch Problem, 86 Cornell L Rev 831, 834–35 (2001) (calling for the abandonment of the avoidance canon on separation-of-powers grounds); John F. Manning, The Nondelegation Doctrine as a Canon of Avoidance, 2000 S Ct Rev 223, 228 (criticizing the enforcement of the nondelegation doctrine through the use of the avoidance canon); Frederick Schauer, Ashwander Revisited, 1995 S Ct Rev 71, 94–95 (criticizing the avoidance canon as being disguised judicial activism); Harry H. Wellington, Machinists v. Street: Statutory Interpretation and the Avoidance of Constitutional Issues, 1961 S Ct Rev 49, 49–50, 73 (criticizing a specific application of the avoidance canon); Clay v Sun Insurance Office Ltd, 363 US 207, 213–14 (1960) (Black dissenting) (accusing the Court of “carrying the doctrine of avoiding constitutional questions to a wholly unjustifiable extreme,” and arguing that “there are times when a constitutional question is so important that it should be decided even though judicial ingenuity would find a way to escape it”); Henry J. Friendly, Mr. Justice Frankfurter and the Reading of Statutes, in Wallace Mendelson, ed, Felix Frankfurter: The Judge 30, 45 (Reynal 1964) (warning that the avoidance canon risks judicial rewriting of statutes); Richard A. Posner, The Federal Courts: Crisis and Reform 284–86 (Harvard 1985) (similar); Reno v Flores, 507 US 292, 314 n 9 (1993) (calling the avoidance canon “the last refuge of many an interpretive lost cause”).
  • 10. See, for example, Zachary Price, The Rule of Lenity as a Rule of Structure, 72 Fordham L Rev 885, 885 (2004) (arguing that the rule “has lately fallen out of favor with both courts and commentators”); The Supreme Court 2007 Term: Leading Cases, 122 Harv L Rev 276, 475 (2008) (“Though lenity was a robust doctrine for much of this country’s legal development, in recent decades lenity has been disfavored, a deciding factor in only a limited subset of cases if at all.”). See also Note, The New Rule of Lenity, 119 Harv L Rev 2420, 2420 (2006).
  • 11. See, for example, Northwest Austin Municipal Utility District Number One v Holder, 557 US 193, 205 (2009); National Federation of Independent Business v Sebelius, 132 S Ct 2566, 2594 (2012).
  • 12. See Table 1. Note also that two of the Court’s textualist-leaning justices, Justices Samuel Alito and Anthony Kennedy, likewise referenced substantive canons at decidedly low rates (< 20.0 percent), as did most of the nontextualist justices. See id. For characterizations of Alito and Kennedy as textualist judges, see Peter J. Smith, Textualism and Jurisdiction, 108 Colum L Rev 1883, 1887 & n 14 (2008) (“[I]t appears that several Justices—clearly Justices Scalia and Thomas, and perhaps Chief Justice Roberts and Justices Alito and Kennedy—on the Supreme Court now consider themselves textualists.”); John F. Duffy, In re Nuijten: Patentable Subject Matter, Textualism and the Supreme Court (Patently-O, Feb 5, 2007), archived at (“[T]here is now likely a majority of current Justices (including the Chief Justice and Justices Scalia, Kennedy, Thomas and Alito) who adhere to some form of fairly rigorous textualism in statutory interpretation.”); Manning, 101 Colum L Rev at 125 & n 505 (cited in note 1) (calling Kennedy a textualist’s “fellow traveler[ ]”).
  • 13. See Appendix (listing cases and substantive canons invoked).
  • 14. See Part III.B.
  • 15. See Appendix; text accompanying notes 140–41.
  • 16. See Part II.C.
  • 17. See Parts II.C.1–2.
  • 18. See Part II.C.3.
  • 19. See Katyal and Schmidt, 128 Harv L Rev at 2112 (cited in note 7) (arguing that the Roberts Court employs “[a]ctive avoidance” that emboldens judicial activism and “leads to tortured constructions of statutes that bear little resemblance to laws actually passed by the elected branches”); Richard M. Re, The Doctrine of One Last Chance, 17 Green Bag 2d 173, 182–84 (2014).
  • 20. See, for example, Abbe R. Gluck, The States as Laboratories of Statutory Interpretation: Methodological Consensus and the New Modified Textualism, 119 Yale L J 1750, 1842 (2010) (asserting that the Supreme Court currently is grappling with the question of “how ambiguity is discerned and, once found, whether legislative history or canons come next,” and that “at least part of what divides textualists from purposivists on the modern U.S. Supreme Court seems to be that textualists put canons second, whereas purposivists choose legislative history most of the time”).
  • 21. See Table 1 (reporting that Scalia referenced substantive canons in 11.0 percent (nine of eighty-two) of the cases he authored and legislative history in 9.8 percent (eight of eighty-two), and that Thomas invoked substantive canons in 11.7 percent (nine of seventy-seven) of the cases he authored and legislative history in 7.8 percent (six of seventy-seven)).
  • 22. William N. Eskridge Jr, Norms, Empiricism, and Canons in Statutory Interpretation, 66 U Chi L Rev 671, 679 (1999). See also Karl N. Llewellyn, Remarks on the Theory of Appellate Decision and the Rules or Canons about How Statutes Are to Be Construed, 3 Vand L Rev 395, 401 (1950) (“[T]o make any canon take hold in a particular instance, the construction contended for must be sold, essentially, by means other than the use of the canon.”).
  • 23. See Gluck, 119 Yale L J at 1778, 1805–06 (cited in note 20) (describing approaches adopted by several state supreme courts).
  • 24. See Jacob Scott, Codified Canons and the Common Law of Interpretation, 98 Georgetown L J 341, 382–401 (2010).
  • 25. See Abbe R. Gluck and Lisa Schultz Bressman, Statutory Interpretation from the Inside—an Empirical Study of Congressional Drafting, Delegation, and the Canons: Part I, 65 Stan L Rev 901, 966 (2013) (showing legislative drafters’ perceptions of which interpretive tools are most useful to courts in determining congressional intent).