By Lawrence B. Solum
Introduction
Because the first-year curriculum emphasizes common-law courses (property, contracts, torts), law students may not encounter the concept of “deference” early on. Nonetheless, understanding deference is important in a wide variety of contexts, including standards of appellate review and judicial review of both legislation and administrative action. This entry in the Legal Theory Lexicon provides a short introduction to the idea of deference.
As always, the Lexicon is aimed at law students with an interest in legal theory.
The Concept of Deference
What does “deference” mean? The standard dictionary definitions define deference as “respect and esteem due a superior or an elder,” but that is not the technical legal meaning of deference. Pinning the concept of “deference” down in a precise way is tricky, but deference seems to involve a relationship between two legal actors or institutions, for example a court and a legislature. Deference usually involves situations in which the deferring institution has some power over the institution to which it might defer. Examples include (1) an appellate court reviewing the decision of a trial court, (2) a court reviewing the constitutionality of legislation, and (3) a court reviewing the legality of action by an administrative agency.
What does it mean to defer to a trial court, legislature, or administrative agency? One approach to that question is to consider the opposite of deference. Nondeferential appellate review of a trial court decision is “de novo”: de novo review requires the appellate court to resolve the issue without regard to the action taken by the trial court. Thus, de novo review of a trial court’s conclusions of law gives no weight to the fact that the trial court has taken a position on the legal question. But when it comes to a trial court judge’s findings of fact, the appellate court does defer. Findings of fact made by a trial court judge are reviewed under the deferential “clearly erroneous” standard. The appellate court will only reverse the trial court if the appellate judges are convinced that the error is “clear.” The finding of fact may be wrong, but not clearly erroneous. The clearly erroneous standard does give weight to the factual determination made by the trial court.
Degrees of Deference
The conventional wisdom is that deference is a matter of degree and not an off-on switch. That is, deference is a scalar and not a binary. For example, the standards of appellate review of trial court decisions are usually ranked as follows:
Most deferential: Abuse of discretion, applies to discretionary decisions by the trial court.
Intermediate deference: Clearly erroneous, applies to factual determinations by trial judges.
Least deferential: De novo, applies to issues of law.
There are interesting questions about the spectrum of deference. One interpretation of the spectrum would assign probability values to degrees of deference. For example, the de novo standard might be interpreted as requiring reversal of a trial court decision if the likelihood that it is incorrect is greater than 0.5. The clearly erroneous standard might be assigned a value of 0.7 and the abuse of discretion standard could be 0.1. But the probability interpretation might not be correct: it could be argued that the different standards of appellate review are qualitatively different.
Deference in the Context of Judicial Review of Legislation
Another important context in which the concept of deference operates is judicial review of legislation for constitutionality. For example, in the context of the Equal Protection Clause, the Supreme Court sometimes applies tiers of scrutiny. Rational basis review is highly deferential. In the most deferential form of rational basis review, legislation is upheld so long as the legislature could conceivably have had a legitimate aim in enacting the legislation and conceivably could have believed that the legislation was a rational means of pursuing that aim. Intermediate scrutiny (which applies to gender) requires more, an important aim and a reasonable relationship between the means and end of the legislation. Strict scrutiny (which applies to race) involves the lowest level of deference: legislation will be upheld only if there is a compelling state interest and the legislative means are actually necessary to achieve this compelling end.
Rational basis scrutiny provides one of the paradigm cases of deference. Even within this category, there seem to be different approaches. The conceivable basis variant of rational basis review is so deferential that it is hard to imagine any legislation that would fail to satisfy the test. But if the government is required to show that the legitimate state interest was the actual purpose of the legislation and that there is evidence supporting the means-ends relationship, then even a deferential standard of review might result in the invalidation of legislation.
Deference and Judicial Review of Agency Action
For many years, the term “deference” arose most frequently in connection with the “Chevron doctrine,” which involved judicial deference to agency interpretations of regulatory statutes. The basic idea of Chevron deference was that courts should defer to the agency’s interpretation of the statute, if the statute was unclear (“ambiguous”) and the agency’s interpretation was reasonable. This form of deference was controversial, because it is in tension with the traditional conception of the judicial role that assigns to courts the primary and ultimate authority for the interpretation and construction of legal texts. Chevron was overruled by the Supreme Court in Loper Bright Enterprises v. Raimondo, 603 U.S. 369 (2024), which held that courts must exercise independent judgment in deciding whether an agency has acted within its statutory authority. The overruling of Chevron has shifted discussion of deference to other doctrines, including what is sometimes called Auer deference—established in Auer v. Robbins, 519 U.S. 452 (1997)—which involves judicial deference to an agency’s interpretation of its own regulations.
Conclusion
There is much more to be said about the idea of deference, but I hope that this brief discussion is sufficient to convey the basic idea of deference and to illustrate its application in a variety of contexts. Additional reading is provided in the bibliography.
Related Lexicon Entries
- Legal Theory Lexicon 054: Standards of Review
- Legal Theory Lexicon 074: Restraint and Constraint in Constitutional Theory
- Legal Theory Lexicon 091: Discretion
Bibliography
- Lisa Schultz Bressman, The Jurisprudence of ‘Degree and Difference’: Justice Breyer and Judicial Deference, 132 Yale L.J.F. (2022).
- Stephen Breyer, Judicial Review of Questions of Law and Policy, 38 Admin. L. Rev. 363 (1986).
- Evan H. Caminker, Thayerian Deference to Congress and Supreme Court Supermajority Rule: Lessons from the Past, 78 Ind. L.J. 73 (2003).
- Paul Daly, Understanding Administrative Law in the Common Law World (Oxford Univ. Press 2021).
- William N. Eskridge, Jr. & Lauren E. Baer, The Continuum of Deference: Supreme Court Treatment of Agency Statutory Interpretations from Chevron to Hamdan, 96 Geo. L.J. 1083 (2008).
- Jacob E. Gersen & Adrian Vermeule, Chevron As A Voting Rule, 116 Yale L.J. 676 (2007).
- Kevin O. Leske, Between Seminole Rock and a Hard(er) Place: A New(er) Approach to Agency Deference, 75 Cath. U. L. Rev. 195 (2025).
- Thomas W. Merrill, The Demise of Deference — And the Rise of Delegation to Interpret?, 138 Harv. L. Rev. 227 (2024).
- Jonathan T. Molot, The Judicial Perspective in the Administrative State: Reconciling Modern Doctrines of Deference with the Judiciary’s Structural Role, 53 Stan. L. Rev. 1 (2000).
- Jeffrey A. Pojanowski, Neoclassical Administrative Law, 133 Harv. L. Rev. 852 (2020).
- Antonin Scalia, Judicial Deference to Administrative Interpretations of Law, 1989 Duke L.J. 511.
- Cass R. Sunstein & Lawrence B. Solum, Chevron as Construction, 105 Cornell L. Rev. 1465 (2020).
Link to the Most Recent Version of this Lexicon Entry
Legal Theory Lexicon 092: Deference
(Last revised on August 25, 2024.)
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