Electronic copy available at: http://ssrn.com/abstract=975102 Electronic copy available at: http://ssrn.com/abstract=975102 Atlantic Divide or Gulf Stream Convergence: Merger Policies in the European Union and the United States by Mats A. Bergman, Malcolm B. Coate, Maria Jakobsson, and Shawn W. Ulrick April 2010 Abstract: We collect a sample of EU and US in-depth merger investigation, estimate models of the regulatory decisions and use the models to compare merger policies in the two jurisdictions. The approach used allows us to decompose observed differences between merger decisions into regime effects and case-mix effects. Focusing on dominant-firm mergers, we find that EU is tougher than the US on average and on mergers resulting in low market shares. We also find that US policy is more affected than EU policy by a range of market considerations. JEL codes: L44, K21 Coate and Ulrick, Bureau of Economics, Federal Trade Commission. Bergman, Södertörn University of South Stockholm. Jakobsson, Stockholm University. The analyses and conclusions set forth in this paper are those of the authors and do not necessarily represent the views of the Federal Trade Commission or any other institution linked to the authors. We would like to thank Denis Breen, Luke Froeb, Paul Pautler, Arthur Del Buono, and Steve Tenn for helpful comments on the project. Thanks also to Johan Stennek, Jerker Holm, Lars Sørgard, Pehr-Johan Norbäck, and other seminar participants at the Norwegian Competition Authority, Lund University, and the Research Institute of Industrial Economics. Moreover, research assistants Anthony Alcorn, Brian Cross, Fulvio Cajina, Paul Golaszewski, Wendy Hanson, Karl Kindler, Michael Madigan, Madeleine McChesney, Brian Murphy, Elisabeth Murphy, Joseph Remy, Adam Schwarz, and Matthew Tschetter played a role in assembling the US data and Johan Gars and Erik Sandgren assisted in assembling the EU data. 1