87.4

I wish to thank Professors Douglas Baird and Anthony Casey, as well as The University of Chicago Law Review editors, for their guidance and advice throughout the writing process.

We thank Shyam Balganesh, Norman Bishara, Michael Burstein, Richard Castanon, Bryan Choi, Victor Fleischer, Lee Fleming, Ronald Gilson, John Goldberg, RobertGomulkiewicz, Charles Tait Graves, Michael Guttentag, Ryan Holte, Justin Hughes,David Levine, Orly Lobel, Greg Mandel, Karl Mannheim, Matt Marx, Adam Mossoff,Natasha Nayak, Ruth Okediji, David Orozco, Eric Posner, Greg Reilly, Michael Risch, Ben Sachs, David Schwartz, Joseph Singer, Henry Smith, Kathy Spier, Matt Stephenson, James Stern, Olav Sorenson, Evan Starr, David Taylor, Saurabh Vishnubhakat, PolkWagner, and Stephen Yelderman, as well as attendees at the 2015 Works in Progress in Intellectual Property Conference, the 2017 Conference of the American Law and Economics Association, and workshops at Harvard Law School, University of Pennsylvania Law School, Loyola Law School, Los Angeles, the Center for Law and the Social Sciences at the University of Southern California School of Law, and the University of San Diego School of Law for their helpful discussions and comments on prior versions of this paper. We also thank Carolyn Ginno, Matthew Arnold, Anna Ayar, Vanand Baroni, Haley Dumas, Ryan Foley, David Javidzad, Rachel Stariha, and Millicent Whitemore for their valuable research assistance.

We are grateful for comments from Bob Bone, Alon Klement, Shay Lavie, Jay Tidmarsh, Diego Zambrano, and participants at the Law Faculty Workshops at the University of Chicago, the University of Notre Dame, Tel Aviv University, and the University of Texas School of Law, as well as the 2018 ALEA Annual Meetings. We thank Ramon Feldbrin, Kathryn Garcia, Sakina Haji, Deanna Hall, Adam Picker, Jill Rogowski, and Kelly Yin for valuable research assistance. William Hubbard thanks the Paul H. Leffmann Fund and the Jerome F. Kutak Faculty Fund for research support.