George Tsebelis’ veto players approach has become a prominent theory to analyze various research questions in political science. Studies that apply veto player theory deal with the impact of institutions and partisan preferences of legislative activity and policy outcomes. It is used to measure the degree of policy change and, thus, reform capacity in national and international political systems. This volume contains the analysis of leading scholars in the field on these topics and more recent developments regarding theoretical and empirical progress in the area of political reform-making. The contributions come from research areas of political science where veto player theory plays a significant role, including, positive political theory, legislative behavior and legislative decision-making in national and supra-national political systems, policy making and government formation. The contributors to this book add to the current scholarly and public debate on the role of veto players, making it of interest to scholars in political science and policy studies as well as policymakers worldwide.

Political scientists have long classified systems of government as parliamentary or presidential, two-party or multiparty, and so on. But such distinctions often fail to provide useful insights. For example, how are we to compare the United States, a presidential bicameral regime with two weak parties, to Denmark, a parliamentary unicameral regime with many strong parties? Veto Players advances an important, new understanding of how governments are structured. The real distinctions between political systems, contends George Tsebelis, are to be found in the extent to which they afford political actors veto power over policy choices. Drawing richly on game theory, he develops a scheme by which governments can thus be classified. He shows why an increase in the number of "veto players," or an increase in their ideological distance from each other, increases policy stability, impeding significant departures from the status quo. Policy stability affects a series of other key characteristics of polities, argues the author. For example, it leads to high judicial and bureaucratic independence, as well as high government instability (in parliamentary systems). The propositions derived from the theoretical framework Tsebelis develops in the first part of the book are tested in the second part with various data sets from advanced industrialized countries, as well as analysis of legislation in the European Union. Representing the first consistent and consequential theory of comparative politics, Veto Players will be welcomed by students and scholars as a defining text of the discipline. From the preface to the Italian edition: ? "Tsebelis has produced what is today the most original theory for the understanding of the dynamics of contemporary regimes. . . . This book promises to remain a lasting contribution to political analysis."--Gianfranco Pasquino, Professor of Political Science, University of Bologna

Combining game theory with unprecedented data, this book analyzes how divided party Presidents use threats and vetoes to wrest policy concessions from a hostile congress.