How do changes in society that increase the heterogeneity of the citizenry shape democratic party systems? This book seeks to answer this question. It focuses on the key mechanism by which social heterogeneity shapes the number of political parties: new social groups successfully forming new, sectarian parties. Why are some groups successful at this while others fail? Drawing on cross-national statistical analyses and case studies of Sephardi and Russian immigration to Israel and African American enfranchisement in the United States, this book demonstrates that social heterogeneity does matter. However, it makes the case that to understand when and how social heterogeneity matters, factors besides the electoral system - most importantly, the regime type, the strategies played by existing parties, and the size and politicization of new social groups - must be taken into account. It also demonstrates that sectarian parties play an important role in securing descriptive representation for new groups.
Heather Stoll is Associate Professor of Political Science at the University of California, Santa Barbara. She holds an MPhil in politics from the University of Oxford and an MS in statistics and PhD in political science from Stanford University. She is a 1996 Harry S. Truman Scholar and a 1997 British Marshall Scholar. Her Stanford dissertation, on which this book is loosely based, was the co-recipient of the Seymour Martin Lipset Award for the best comparative politics dissertation in 2005. She has published a number of articles in a variety of journals, including the Journal of Politics, Comparative Political Studies, Party Politics and West European Politics.