Scott Mainwaring is Chair and Professor of Government at the University of Notre Dame. He is author or co-editor of Building Democratic Institutions: Party Systems in Latin America (Stanford University Press, 1995), Issues in Democratic Consolidation: The New South American Democracies in Comparative Perspective (University of Notre Dame Press, 1992), The Progressive Church in Latin America (University of Notre Dame Press, 1989), and The Catholic Church and Politics in Brazil, 1916-1985 (Stanford University Press, 1986). Matthew S. Shugart is Professor at the Department of Political Science and the School of International Relations and Pacific Studies, University of California, San Diego. Among his books are Seats and Votes (with Rein Taagepera, 1989), Presidents and Assemblies (with John Carey, Cambridge University Press, 1992), Presidentialism and Democracy in Latin America (co-edited with Scott Mainwaring, Cambridge University Press, 1997), Executive Decree Authority (co-edited with John Carey, Cambridge University Press, 1998), and Mixed-Member Electoral Systems (co-edited with Martin Wattenberg, 2001). His articles have appeared in numerous journals, including the American Journal of Political Science, the American Political Science Review, the British Journal of Political Science, and Electoral Studies.