The author thanks the department editor, associate editor, referee team, and Pierre Azoulay, Christian Catalini, Hong Luo, Fiona Murray, Timothy Simcoe, Olav Sorenson, Scott Stern, and Ezra Zuckerman for thoughtful and constructive comments and seminar participants at Boston University, Columbia University, Duke University, Harvard University, Massachusetts Institute of Technology, New York University, National Bureau of Economic Research, Stanford University, University College London, University of California Los Angeles, University of Pennsylvania, University of Southern California, and University of Toronto for feedback. All errors remain the author’s own.