 He was a Law Clerk to Judge Alex Kozinski of the United States Court of Appeals for the Ninth Circuit in 1986.Knoll is the Theodore K. Warner Professor of Law & Professor of Real Estate at the University of Pennsylvania Law School, Co-Director of the Center for Tax Law and Policy and the Deputy Dean.Among his many articles are "The Connection between Competitiveness and International Taxation," 65 "Tax Law Review" 349 (2012), “Reconsidering International Tax Neutrality,” 64 "Tax Law Review" 99 (2011), and “The Corporate Income Tax and the Competitiveness of U.S. Industries,” 63 "Tax Law Review" 771 (2010).