In recent years collective litigation procedures have spread across the globe, accompanied by hot controversy and normative debate. Yet virtually nothing is known about how these procedures operate in practice. Based on extensive documentary and interview research, this volume presents the results of the first comparative investigation of class actions and group litigation 'in action'. Produced by a multinational team of legal scholars, this book spans research from ten different countries in the Americas, Europe, Asia and the Middle East, including common law and civil law jurisdictions. The contributors conclude that to understand how class actions work in practice, one needs to know the cultural factors that shape claiming, the financial arrangements that enable or impede litigation and how political actors react when mass claims erupt. Substantive law and procedural rules matter, but culture, economics and politics matter at least as much. This book will be of interest to students and scholars of law, business and politics. It will also be of use to public policy makers looking to respond to mass claims; financial analysts looking to understand the potential impact of new legal instruments; and global lawyers who litigate transnationally.