Aaron Nielson

Professor of Law

Professor Nielson lectures and writes in the areas of administrative law, civil procedure, and federal courts. His publications have appeared in journals such as the University of Pennsylvania Law Review, Duke Law Journal, University of Chicago Law Review, Northwestern University Law Review, and Georgetown Law Journal. He recently served as Chair of the Administration and Management Committee of the Administrative Conference of the United States, a federal agency that studies the administrative process and makes recommendations on ways to improve it. He also recently served on the Council of the American Bar Association’s Section of Administrative Law & Regulatory Practice. He currently co-chairs the Section's Antitrust & Trade Regulation Committees. Professor Nielson is a permanent commentator at the Yale Journal on Regulation's Notice & Comment blog where he focuses on the U.S. Court of Appeals for the District of Columbia Circuit. He has been quoted regarding the D.C. Circuit in the Wall Street Journal, the Washington Post, Bloomberg BNA, the National Law Journal, and Law360.

Professor Nielson was appointed by the U.S. Supreme Court to brief and argue Collins v. Yellen, a separation-of-powers case about the Federal Housing Finance Agency.

Before joining the faculty, Professor Nielson was a partner in the Washington, D.C. office of Kirkland & Ellis LLP. He also has served as a law clerk to Justice Samuel A. Alito, Jr. of the U.S. Supreme Court, Judge Janice Rogers Brown of the U.S. Court of Appeals for the D.C. Circuit, and Judge Jerry E. Smith of the U.S. Court of Appeals for the Fifth Circuit.

Professor Nielson received his J.D. from Harvard Law School. Following graduation, he was awarded a Harvard Law School Post-Graduate Research Fellowship. Professor Nielson also received an LL.M from the University of Cambridge, where he focused his studies on the institutions that regulate global competition and commerce. He received his undergraduate degree from the University of Pennsylvania, majoring in economics and political science.

Courses Taught

  • Administrative Law
  • Civil Procedure
  • Federal Courts
  • Washington Law Seminar


  • J.D., Harvard Law School
  • LL.M, University of Cambridge
  • B.A., University of Pennsylvania
  • Congress’s Anti-Removal Power, 76 Vanderbilt Law Review  1 (2023) (with Christopher Walker).
  • Gaming Certiorari, 170 University of Pennsylvania Law Review 1329 (2022) (with Paul Stancil).
  • Qualified Immunity’s 51 Imperfect Solutions, Duke Journal of Constitutional Law & Public Policy 321 (2022) (with  Christopher J. Walker).
  • The Minor Questions Doctrine, 169 University of Pennsylvania Law Review 1181 (2021). [SSRN]
  • Deconstruction, Not Destruction, 150(3) Daedalus: The Journal of the American Academy of Arts & Sciences (Spring 2021). [SSRN]
  • Three Views of the Administrative State: Lessons from Collins v. Yellen, 2020-2021 Cato Supreme Court Review 141 (2021).  [SSRN]
  • Three Wrong Turns in Agency Adjudication, 28 George Mason Law Review 657 (2021). [SSRN]
  • Narrowing Chevron’s Domain, 70 Duke Law Journal 931 (2021) (with Kristin E. Hickman). [SSRN]
  • Foreword: The Future of Chevron Deference, 70 Duke Law Journal 1015 (2021) (with Kristin E. Hickman). [SSRN]
  • Qualified Immunity and Federalism, 109 Georgetown Law Journal 229 (2020) (with Christopher J. Walker). [SSRN]
  • Sticky Regulations and Net Neutrality Restoring Internet Freedom, 71 Hastings Law Journal 1208 (2020). [SSRN]
  • The Policing of Prosecutors: More Lessons from Administrative Law?, 123 Dickinson Law Review 713 (2019). [SSRN]
  • Sticky Regulations, 85 University of Chicago Law Review 85 (2018). [SSRN]
  • How Agencies Choose Whether to Enforce the Law: A Preliminary Investigation, 93 Notre Dame Law Review 1517 (2018). [SSRN]
  • A Qualified Defense of Qualified Immunity, 93 Notre Dame Law Review 1853 (2018) (with Christopher J. Walker). [SSRN]
  • Optimal Ossification, 86 George Washington Law Review 1209 (2018). [SSRN]
  • A(nother) New Plan for Clerkship Hiring, 102 Judicature, no. 2, Summer 2018, at 70 (debate with Judge Diane P. Wood). [SSRN]
  • Chevron Step One-and-a-Half, 84 University of Chicago Law Journal 757 (2017) (with Daniel Hemel). [SSRN]
  • Clarence Thomas the Questioner, 111 Northwestern University Law Review 1185 (2017) (with RonNell Andersen Jones). [SSRN]
  • Confessions of an “Anti-Administrativist”, 131 Harvard Law Review Forum 1 (2017). [SSRN]
  • Beyond Seminole Rock, 105 Georgetown Law Journal 943 (2017). [SSRN]
  • Strategic Immunity, 66 Emory Law Journal 55 (2016) (with Christopher Walker). [SSRN]
  • The New Qualified Immunity, 89 Southern California Law Review 1 (2015) (with Christopher Walker). [SSRN]
  • Visualizing Change in Administrative Law, 49 Georgia Law Review 757 (2015). [SSRN]
  • The Future of Federal Law Clerk Hiring, 98 Marquette Law Review 181 (2014). [SSRN]
  • In Defense of Formal Rulemaking, 75 Ohio State Law Journal 237 (2014). [SSRN]
  • Reflections on the End of the Federal Law Clerk Hiring Plan, 112 Michigan Law Review First Impressions 22 (2013). [SSRN]
  • Erie as Nondelegation, 72 Ohio State Law Journal 239 (2011). [SSRN]
  • Hiding Nondelegation in Mouseholes, 62 Administrative Law Review 19 (2010) (with Jacob Loshin). [SSRN]
  • The Death of the Supreme Court’s Certified Question Jurisdiction, 59 Catholic University Law Review 483 (2010). [SSRN]
  • U.S. Supreme Court, Law Clerk to Justice Samuel A. Alito, Jr. (2014-15).
  • Kirkland & Ellis LLP, Washington, D.C. (2007, 2009-12).
  • U.S. Court of Appeals for the D.C. Circuit, Law Clerk to Judge Janice Rogers Brown (2008-09).
  • U.S. Court of Appeals for the Fifth Circuit, Law Clerk to Judge Jerry E. Smith (2007-08).
  • U.S. Senate Judiciary Committee, Constitutional Law Unit (Summer 2006).
  • U.S. Department of Justice, Office of Legal Policy (Winter 2005).
  • Office of Counsel to the President (Summer 2005).
  • Federal Trade Commission, Office of Policy Planning (Summer 2004).
  • The Better Business Bureau of Central, Northern & Western Arizona (Summer 2003)