An ambitious synthesis, Positive Theories of Congressional Institutions attempts to reconcile a number of rational choice viewpoints to produce a comprehensive look at congressional institutions. While most theorists have presented their work as exclusive alternatives for understanding Congress, this volume reconsiders that basic premise. If in fact these approaches are mutually exclusive, what evidence favors one over the other? Could it be that these views focus on different aspects of a more complex puzzle? Kenneth A. Shepsle and Barry R. Weingast have assembled leading proponents of rational choice approaches to debate these issues. Some emphasize the problems of legislative decisionmaking under uncertainty and the role institutions play in providing incentives for relevant actors to provide information. Other theorists focus on political parties and emphasize the conditions under which parties exercise institutional authority and monitor institutional practices (or fail to do so). Still others investigate legislative delegation, both within and without the legislature. In debating the relationships between these research strands, the contributors not only provide powerful evidence for the power of formal modelling but also invite those involved in other modes of research to join the discussion. Thus the volume suggests how a more satisfying and complete model might emerge. Positive Theories of Congressional Institutions is a timely volume that will provide the foundation for all future work in this area. Contributors include John H. Aldrich, David P. Baron, Gary W. Cox, John A. Ferejohn, Morris P. Fiorina, Thomas W. Gilligan, Keith Krehbiel, John Londregan, Arthur Lupia, Mathew D. McCubbins, Forrest Maltzman, David W. Rohde, Kenneth A. Shepsle, Barbara Sinclair, Steven S. Smith, James Snyder, and Barry R. Weingast. Kenneth A. Shepsle is Professor of Government, Harvard University. Barry R. Weingast is Professor of Political Science and Senior Fellow, Hoover Institution, Stanford University.