A substantial body of research suggests that the United States has a distinctive legal style characterized by detailed rules, extensive transparency requirements, adversarial procedures for dispute resolution, costly legal contestation involving many lawyers, and frequent judicial intervention in administrative affairs. Recently, scholars of comparative law and public policy have asked whether this American legal style is spreading around the world. Some scholars have argued that legal styles are converging on an American model, while others have argued that distinctive national legal styles will persist. This article addresses this emerging debate. We argue that American legal style is spreading to other jurisdictions. However, we depart from predominant explanations, which attribute convergence to international regulatory competition or emulation. Instead, we argue that economic liberalization and political fragmentation have undermined traditional approaches to regulation and have generated functional pressures and political incentives to shift toward American legal style.The authors thank Kenneth Abbott, Ward Bower, Kent Calder, Robert G. DeLaMater, Tom Ginsburg, Jack Goldsmith, Milton Heumann, Mark D. Hunsaker, Nicolas Jabko, Robert Kagan, Susan Lawrence, Kathleen McNamara, Michael Paris, Mark Ramseyer, Amy Searight, Anne-Marie Slaughter, Tatsushi Terada, David Vogel, Albert Yoon, and participants in presentations at the 2001 International Studies Association Convention, the 2001 American Political Science Association Convention, Northwestern University's Center for International and Comparative Studies, the University of Chicago Law School, and Princeton University's Center of International Studies for their comments on earlier versions of the article. The authors thank Rachael Snyder, Fatima Khan, Hisako Yamamoto, Masako Ishiwata, and Kei Yamaguchi for their research assistance and Akiko Tsuda, Akemi Ideuchi, and Mio Kato for secretarial assistance. Kelemen thanks the Frank Kneller Fund at Rutgers University and the Center of International Studies at Princeton University for financial support. Views expressed herein are those of the authors alone and are not necessarily those of any institutions with which they are affiliated.