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Major Rules in the Courts

An Empirical Study of Challenges to Federal Agencies’ Major Rules

This working paper summarizes the first empirical study of how major rules, as defined under the Congressional Review Act (CRA), fare in federal court. A summary of the study’s high-level findings can be found at

The authors chose major rules for several reasons, namely, the ability to conduct an apples-to-apples comparison across administrations while focusing attention on the most important agency actions. The study summarized in this article covers each of the 1,870 major rules issued from the CRA’s enactment in 1996 through the end of the Trump Administration. The roughly 24-year period covering four administrations (two from each party) is the longest continuous timespan of any empirical study of agency win rates.

The article’s title is perhaps ironic given that most major rules (78.8%) do not end up in court, which is itself notable because most previous studies of agency win rates focus only on the relatively small percentage of agency actions that end up in court. The study finds that the challenge rate has steadily increased over time, rising from 16.8% for the Clinton Administration to 28.1% for the Trump Administration. Courts are thus resolving more challenges to major rules than they once did.

The study also finds lower agency win rates than other studies, which typically report win rates of 60–70%. In contrast, the study finds win rates of 49.1% or 56.1%, depending on the unit of analysis (major rules or controlling opinions resolving challenges to major rules). It further finds that win rates declined over time: The Clinton Administration saw 63.0% of its major rules upheld and 63.3% of controlling opinions rule in favor of its major rules; the Trump Administration saw 31.2% of its major rules upheld and 41.5% of controlling opinions rule in favor of its major rules. The two intervening administrations were in between but closer to the range’s upper end. These results suggest that, while agency win rates declined over time, the Trump Administration’s win rates were unusually low. In addition to documenting these agency challenge and win rates, the article also covers data collected on other topics ranging from forum shopping, differences between independent and executive agencies, partisan trends, Chevron deference, and more.

The article concludes with observations on the Biden Administration’s major rules to date. Because the Biden Administration is still issuing rules and most challenges to its finalized rules remain ongoing, its major rules are analyzed separately from the primary dataset. Based on data collected in December 2023, agency win rates have ticked back up during the Biden Administration, but they have not returned to their earlier highs: The Biden Administration has seen 40.7% of its major rules upheld and 47.9% of controlling opinions rule in favor of its major rules.

All told, the study suggests that the conventional wisdom that agencies win two-thirds of the time no longer holds true, at least not for major rules. But the vast majority of major rules go unchallenged, revealing that most major rules survive, despite declining trends in agency win rates. Complete analysis of the Biden Administration’s major rules in a future study is necessary to clarify whether the Trump Administration’s win rate was aberrational or a dip in a longer downward trend.