Norman Schofield is Taussig Professor in Political Economy at Washington University in St Louis. He has served as Fulbright Distinguished Professor of American Studies at Humboldt University Berlin in 2003-04, and held a Fellowship at the Center for Advanced Study in the Behavioral Sciences at Stanford in 1988-89. Professor Schofield is the author of Architects of Political Change (Cambridge University Press, 2006), Mathematical Methods in Economics and Social Choice (2003), Multiparty Government (coauthored with Michael Laver, 1990), and Social Choice and Democracy (1985). He received the William Riker Prize in 2002 for contributions to political theory and is corecipient with Gary Miller of the Jack L. Walker Prize for the best article on political organizations and parties in the American Political Science Review for 2002-04. Itai Sened is Professor and Chair of the Department of Political Science at Washington University in St Louis. He has also served as Director of the Center for New Institutional Social Sciences there since 2000, and formerly taught at Tel Aviv University. Professor Sened is coauthor (with Gideon Doron) of Political Bargaining: Theory, Practice, and Process (2001), author of The Political Institution of Private Property (Cambridge University Press, 1997), and coauthor (with Jack Knight) of Explaining Social Institutions (1995). His research has been published in leading journals such as the American Political Science Review, American Journal of Political Science, Journal of Politics, Journal of Theoretical Politics, British Journal of Political Science, and the European Journal of Political Research.