A huge literature contemplates the theoretical relationship between judicial deference and agency rulemaking. But relatively little empirical work has studied the actual effect of deference on how agencies draft regulations. As a result, some of the most important questions surrounding deference—whether it encourages agencies to focus on policy analysis instead of legal analysis, its relationship to procedures like notice and comment—have so far been dominated by conjecture and anecdote.
Because Chevron, U.S.A., Inc. v. Natural Resources Defense Council, Inc. applied simultaneously across agencies, it has been difficult to separate its specific causal effect from other contemporaneous events in the 1980s, like the rise of cost-benefit analysis and the new textualism. This Article contends with this problem by exploiting a unique event in administrative law: the Supreme Court’s 2011 decision in Mayo Foundation v. United States, which required that courts apply Chevron deference to interpretative tax regulations. By altering the deference regime applicable to one specific category of regulation, Mayo created a natural experiment with a treatment group (interpretative tax regulations) and a control group (all other regulations).

Included in

Law Commons