This Article presents findings from the most comprehensive empirical study to date on how the federal courts of appeals have applied Chevron deference--the doctrine under which courts defer to a federal agency's reasonable interpretation of an ambiguous statute that it administers. Based on 1,558 agency interpretations the circuit courts reviewed from 2003 through 2013 (where they cited Chevron), we found that the circuit courts overall upheld 71% of interpretations and applied Chevron deference 77% of the time. But there was nearly a twenty-five-percentage-point difference in agency-win rates when the circuit courts applied Chevron deference than when they did not. Among many other findings, our study reveals important differences across circuits, agencies, agency formats, and subject matters as to judicial review of agency statutory interpretations.
Based on prior empirical studies of judicial deference at the Supreme Court, however, our findings suggest that there may be a Chevron Supreme and a Chevron Regular: whereas Chevron may not have much of an effect on agency outcomes at the Supreme Court, Chevron deference seems to matter in the circuit courts. That there is a Chevron Supreme and a Chevron Regular may suggest that, in Chevron, the Supreme Court has an effective tool to supervise lower courts' review of agency statutory interpretations. To render Chevron more effective in creating uniformity throughout the circuit courts, the Supreme Court needs to send clearer signals on how courts should apply the deference standard.
INTRODUCTION I. CHEVRON'S EVER-CHANGING ROLE A. Discursive Deference to Agencies Before Chevron B. Chevron and Its Domain 1. The Role of Formality 2. Sensitive Questions C. Chevron for Thee, But Not for Me II. EMPIRICAL STUDY OF JUDICIAL DEFERENCE A. Prior Empirical Studies of Chevron 1. Key Studies Concerning the Supreme Court 2. Key Studies Concerning Circuit Courts B. Our Study Design and Methodology C. Overview of Our Dataset III. GENERAL FINDINGS ON CHEVRON IN THE CIRCUIT COURTS A. Agency-Win Rates and Deference Differences B. How Chevron Is Applied C. Rulemaking Versus Adjudication 1. Agency Procedure and Overall Agency-Win Rates 2. Agency Procedure and Chevron IV. FINDINGS ON CIRCUIT DISPARITIES V. FINDINGS ON AGENCY AND SUBJECT MATTER DIFFERENCES A. Subject Matter Differences B. Agency Deference Rankings C. Executive Versus Independent Agencies VI. ADDITIONAL FINDINGS: WHAT ELSE MATTERS? A. Sensitive Matters B. Interpretive Continuity C. Traditional Deference Factors or Theoretical Grounds CONCLUSION INTRODUCTION
It is a bedrock principle of administrative law that a reviewing court must defer to a federal agency's reasonable interpretation of an ambiguous statute it administers. (1) This Chevron deference doctrine is both untouchable and yet always under attack. Chevron deference has been a cornerstone of judicial review of agency action for more than thirty years, and the decision itself is one of the most cited Supreme Court decisions of all time. Indeed, as of this writing, Chevron has been cited in more than 80,000 sources available on Westlaw, including in roughly 15,000 judicial decisions and nearly 18,000 law review articles and other secondary sources. (2)
In these tens of thousands of sources, scholars, litigants, and judges have contested Chevron's theoretical grounding, (3) its provenance, (4) and its impact on case outcomes. (5) More recently, Supreme Court justices have questioned not only Chevron's reach (6) but also its very existence. (7) Congressional Republicans have followed suit by introducing legislation that would abolish Chevron deference and require courts to review agency statutory and regulatory interpretations de novo. (8)
Much scholarly attention focuses on the use or absence of Chevron deference at the Supreme Court. Some scholars have focused on Chevron's domain--that is, when Chevron applies in judicial review. (9) Others have considered empirically how consistently the Court applies Chevron. In their leading study concerning agency deference in the Supreme Court from 1984 to 2006, Bill Eskridge and Lauren Baer found that the Court applied Chevron deference only one quarter of the time that it would have seemed to apply. (10) When the Court applied the doctrine, agencies prevailed 76.2% of the time, a rate similar to those under other standards of review. (11)
In other words, the Court's choice to apply Chevron deference, as opposed to a less-deferential doctrine or no deference at all, does not seem to affect the outcome of the case. Chevron deference--at least at the Supreme Court--does not seem to matter. As Richard Pierce has concluded, "There is no empirical support for the widespread belief that choice of doctrine plays a major role in judicial review of agency actions." (12) Scholars and commenters, moreover, have noticed the Court's recent treatment of Chevron as a doctrine to ignore, disparage, or distinguish. (13)
But Chevron in the Supreme Court is not our focus. Instead, we are most concerned here with how Chevron works on the ground in the circuit courts. Prior empirical studies of Chevron in the circuit courts were limited to a particular court, (14) particular agencies, (15) particular subject matter, (16) or a short timeframe. (17) They have also largely concentrated on the rates at which agencies prevail under Chevron and the likelihood of judges' policy preferences affecting Chevron's application. (18) Our inquiry and scope are significantly broader.
This Article presents the findings of the largest empirical study of Chevron in the circuit courts to determine how Chevron works outside the marbled enclave of One First Street. Our database of 2,272 judicial decisions, collected with broad search parameters, attempts to cull all published decisions from the circuit courts over an eleven-year period (2003-2013) that refer to the Chevron doctrine. Within the relevant 1,327 of those collected opinions, we uncovered 1,558 instances of judicial review of an agency statutory interpretation (not merely any kind of agency action). Largely following Eskridge and Baer's methodology, we coded each agency statutory interpretation with respect to nearly forty different variables, including information about the decision (circuit, year, judges, and separate opinions); information about the agency interpretation (the agency, subject matter, final agency decisionmaker, agency procedure used, and ideological valence of agency's interpretation); and information about the judicial outcome (outcome as to agency, ideological valence of the decision, standard of review applied, and factors that influenced the court's decision). (19) This broad set of cases permitted us to consider all instances within our parameters in which the circuit courts applied the Chevron framework. This set also permitted us to review all instances in which the circuit courts, having referred to Chevron, reviewed agency interpretations de novo or under the Skidmore deference regime (under which courts defer to an agency's interpretation based on several factors, including the thoroughness of the agency's interpretation and its consistency with prior pronouncements). (20)
This treasure trove of data, albeit with methodological limitations that we discuss in Section II.B, provides a number of often-surprising insights regarding deference to agency statutory interpretations in the circuit courts. Many of these findings suggest, with some caveats, that there may be a Chevron Supreme and a Chevron Regular: whereas the choice to apply Chevron deference may not matter that much at the Supreme Court, it seems to matter in the circuit courts. Consider the following key findings from the study:
First, agency interpretations were significantly more likely to prevail under Chevron deference (77.4%) than Skidmore deference (56.0%) or, especially, de novo review (38.5%). In other words, agencies won significantly more in the circuit courts when Chevron deference applied, at least when the court expressly considered whether to apply Chevron. Indeed, there was nearly a twenty-five-percentage-point difference in agency-win rates with Chevron deference (77.4%) than without (53.6%). Because the agency-win rates in Eskridge and Baer's study of the Supreme Court were much more similar no matter whether Chevron (76.2%), Skidmore (73.5%), or de novo review (66.0%) applied, this was one of our first indications that Chevron Supreme differs from Chevron Regular. (21)
Second, when Chevron's well-known two-step approach applied, the circuit courts resolved the matter at step one (i.e., the step at which the courts ask whether Congress's intent was clear) 30.0% of the time, and, of those Chevron step-one decisions, agencies prevailed 39.0% of the time. Of the 70.0% of the interpretations that moved to Chevron step two (the step at which the courts defer to reasonable agency interpretations when Congress's intent was not clear at step one), the agency prevailed 93.8% of the time. Based on albeit-dated data from Tom Merrill, Chevron Supreme does not behave like Chevron Regular. Merrill found that the Supreme Court resolved matters in the agency's favor 59% of the time at step one. (22) (Merrill--and others after him--did not report comparable data about the Supreme Court's step-two practice.) This difference may suggest that, given the higher likelihood of circuit-court review than Supreme Court review, agencies should give closer attention to the statutory language but that their step-two explanations are largely sufficient. (23)
Third, as expected and as in the Supreme Court, formal agency interpretations prevailed at higher rates than informal ones, without regard to scope of review. But unlike in the Supreme Court, where the agency-win rate for formal adjudication (65.4%) was lower than notice-and-comment rulemaking (72.5%), (24) agency-win rates in formal adjudication were slightly...