Party System Change in Legislatures Worldwide

Carol Mershon is an Associate Professor of Politics at the University of Virginia. She received her PhD in Political Science, with distinction, from Yale University. She has taught at the Institut d'Études Politiques de Lille, served as political science program director at the National Science Foundation, and is a former president of the American Political Science Association's Conference Group on Italian Politics and Society. Mershon's articles have appeared in journals such as the American Political Science Review, the American Journal of Political Science, Comparative Politics, Comparative Political Studies, Electoral Studies and the Journal of Politics, among others. She is the author of The Costs of Coalition (2002) and the co-editor of Political Parties and Legislative Party Switching (2009). The recipient of two awards from the National Science Foundation, Mershon has also held two Fulbright grants and a Social Science Research Council Fellowship. Olga Shvetsova is an Associate Professor of Political Science at Binghamton University. She received her PhD from the California Institute of Technology, and previously taught at Washington University, St Louis and Duke University. Shvetsova works in the fields of constitutional political economy and institutional design. Her work has been published in the American Journal of Political Science, Comparative Political Studies, Constitutional Political Economy, Electoral Studies, the Journal of Democracy, the Journal of Theoretical Politics, the Law and Society Review, Legislative Studies Quarterly, and other peer-reviewed journals. She has authored a number of chapters in edited volumes, and is the co-author of Designing Federalism (Cambridge, 2004).

'Future scholars will be much more careful to treat political parties as endogenous coalitions of legislators and party system dynamics as the evolution of these coalitions. Mershon and Shvetsova offer an excellent starting point for this discussion. It is also very welcome to find a well-crafted new book blending theory and empirics in the best traditions of modern comparative politics.' Michael Laver, New York University

• Part I. The Prospect of Party-System Change between Elections: 1. The phenomenon of party and party-system change; 2. How parliamentary party-system change matters for policy; 3. Why and how individual incumbents change legislative party systems; Part II. Discerning Mechanisms through Case Studies: 4. Legislators' pursuit of benefits and legislative party-system change; 5. Avoidance of electoral costs and stability in parliamentary parties; Part III. Generalizing in a Broader Empirical Setting: 6. Setting up the analysis of 110 parliaments; 7. Institutional inducements and preference-based deterrents to legislative party-system change; 8. Comparative statics: where our assumptions may not apply; 9. Conclusions.