Lloyd has published scholarship on a variety of applications of economics to law, including a market in transplant organs, marriage and divorce, wrongful death, tender offers, and free riders and holdouts. Before joining the faculty of George Mason in 1993, he taught law at Chicago-Kent College of Law and was a John M. Olin Research Fellow at the University of Chicago. Cohen has served as a special counsel to the U.S. International Trade Commission and as a law clerk to Judge Gerald B. Tjoflat of the U.S. Court of Appeals for the Eleventh Circuit. Before attending law school, he was an economics professor.