At the center of contemporary debates over public law lies administrative agencies’ discretion to impose rules. Yet for every one of these rules, there are also unrules nearby. Often overlooked and sometimes barely visible, unrules are the decisions that regulators make to lift or limit the scope of a regulatory obligation through, for instance, waivers, exemptions, or exceptions. In some cases, unrules enable regulators to reduce burdens on regulated entities or to conserve valuable government resources in ways that make law more efficient. However, too much discretion to create unrules can facilitate undue business influence over the law, weaken regulatory schemes, and even undermine the rule of law. In this Article, we conduct the first systematic empirical investigation of the hidden world of unrules. Using a computational-linguistic approach to identify unrules across the Federal Register, the Code of Federal Regulations, and the United States Code, we show that unrules are an integral and substantial feature of the federal regulatory system. Our analysis shows that, by several conservative measures, there exists one obligation-alleviating word for approximately every five to six obligation-imposing words in federal law. We also show that unrules are surprisingly unrestrained by administrative law. In stark contrast to administrative law’s treatment of obligation-imposing rules, regulators enjoy greater discretion when deploying unrules to alleviate regulatory obligations. As a result, a major form of agency power remains hidden from view and relatively unencumbered by law. Recognizing the central role that unrules play in our regulatory system reveals the need to reorient administrative law and incorporate unrules more explicitly into its assumptions, doctrines, and procedures.

* Cary Coglianese is the Edward B. Shils Professor of Law, Professor of Political Science, and Director of the Penn Program on Regulation, University of Pennsylvania Law School. Gabriel Scheffler is an Associate Professor of Law, University of Miami School of Law. Daniel E. Walters is an Assistant Professor of Law, Pennsylvania State University Law School.