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....