This draft was previously titled “Measuring Preemptive Entry in Dynamic Oligopoly Games.” The authors thank Victor Aguirregabira, Panle Jia Barwick, Ron Borkovsky, Rob Clark, Adam Dearing, Alon Eizenberg, Paul Ellickson, Nagesh Gavirneni, Sachin Gupta, Brett Hollenbeck, Mitsuru Igami, Kenneth Judd, Vrinda Kadiyali, Jura Liaukonyte, Cynthia Lin Lawell, Yao Luo, Mathew Osborne, Arvind Magesan, Guillermo Marshall, Frank Mathewson, Sridhar Moorthy, Young-Hoon Park, Marcin Peski, Tiago Pires, Tom Ross, Mario Samano, David Soberman, Eduardo Souza-Rodrigues, Junichi Suzuki, Kosuke Uetake, and Ralph Winter for valuable suggestions; Dimitrios Dimitropoulos for sharing data; and the workshop and conference participants at University of Hawaii, Strategy Science Conference 2022, Summer Institute in Competitive Strategy (SICS), Industrial Organization Conference Canada, Queen’s University, European Association for Research in Industrial Economics (EARIE) Conference 2015, and International Industrial Organization Conference (IIOC) 2017 for helpful comments.