The authors thank Colleen Carey, Sachin Gupta, Amalia Miller, Richard Mortimer, Sebastian Tello-Trillo, David Wierz, and seminar participants at the American Society of Health Economists Annual Conference, the Annual Conference of the European Association for Research in Industrial Economics, Johns Hopkins University, Johns Hopkins Carey School of Business, New York University Stern School of Business, the University of Virginia, and the Wharton School at the University of Pennsylvania for helpful comments. Kevin Wang provided excellent research assistance.