Party System Change in Legislatures Worldwide

In this book, Carol Mershon and Olga Shvetsova explore one of the central questions in democratic politics: how much autonomy do elected politicians have to shape and reshape the party system on their own, without the direct involvement of voters in elections? Mershon and Shvetsova's theory focuses on the choices of party membership made by legislators while serving in office. It identifies the inducements and impediments to legislators' changes of partisan affiliation, and integrates strategic and institutional approaches to the study of parties and party systems. With empirical analyses comparing nine countries that differ in electoral laws, territorial governance and executive-legislative relations, Mershon and Shvetsova find that strategic incumbents have the capacity to reconfigure the party system as established in elections. Representatives are motivated to bring about change by opportunities arising during the parliamentary term, and are deterred from doing so by the elemental democratic practice of elections.

'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, 'What happens between elections during the life of a parliament when politicians engage in career calculations with potential policy implications? Party switching may only occasionally have broad impact in congressional-style legislatures, but in multiparty parliaments, as Mershon and Shvetsova so compellingly show in this new book, such machinations can shift policy, undo governments, and realign coalitions. The authors provide a compelling theoretical argument, rich case studies, and systematic quantitative evidence, shining a bright light on this important topic.' Kenneth A. Shepsle, George Markham Professor of Government, Harvard University

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).