Professor Nielson teaches and writes in the areas of civil procedure, federal courts, antitrust, and administrative law.  His scholarship focuses on the relative competencies of courts, agencies, and legislatures to craft economic policy.  His publications have appeared in journals such as the Ohio State Law Review, Administrative Law Review, and the Harvard Journal of Law and Public Policy.

Before joining the faculty, Professor Nielson was a partner in the Washington, D.C. office of Kirkland & Ellis LLP, where he specialized in antitrust and appellate litigation.  He also served as a law clerk to 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. magna cum laude from Harvard Law School.  Following graduation, he was awarded a Harvard Law School Post-Graduate Research Fellowship.  Professor Nielson also received an LL.M with first class honors 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.