Parliamentarism versus presidentialism in the policy arena

The long-standing debate between advocates of parliamentary and presidential government has recently focused on questions of policy making and implementation. Does the policy process in systems with fused powers differ in systematic and important ways from separation of powers systems? This review essay evaluates six attributes of the policy process-the number of veto players, the site of policy negotiations, the provision of collective goods, accountability, interest group strategies, and delegation to bureaucrats-through three collections of case studies. Many, but not all, of the apparent regular differences between parliamentarism and presidentialism break down because of institutional variation within each governmental type.