The authors gratefully acknowledge comments from editor Nicholas Argyres, two anonymous reviewers, Rajshree Agarwal, Alex Bitekhtine, Wilbur Chung, John de Figueiredo, Brent Goldfarb, Amy Hillman, Guy Holburn, Jean Lanjouw, Keith Maskus, Joe Mahoney, Lee Preston, Michael Ryall, Rick Vandenburgh, and seminar participants at the Academy of Management Conference, INSEAD, Melbourne Business School, the Strategic Management Society, the University of Illinois Urbana–Champaign, and the University of Maryland, College Park. Walter Park was particularly generous in sharing his international patent index data. Andras Ballard, Steve Hsu, Eric Koong, and Ken Liang provided valuable research assistance. The views expressed in this paper are those of the authors and should not be attributed to any U.S. department or agency. An early and abbreviated version of this work appears in the Academy of Management Best Paper Proceedings (2007).