His research focuses on the causes and consequences of government regulation, with a specific focus on food and drug regulation, occupational licensing laws, and advertising regulation. Recent publications include “The Effects of Occupational Licensing Laws on Minorities: Evidence from the Progressive Era” (forthcoming in the Journal of Law and Economics, May 2009, co-authored with Mindy S. Marks); “The Political Economy of Truth-in-Advertising Regulation during the Progressive Era” (Journal of Law and Economics, May 2008, co-authored with Zeynep K. Hansen); and “How Do Regulators Regulate? Enforcement of the Pure Food and Drugs Act, 1907-38″ (Journal of Law, Economics, and Organization_, October 2006).