Partisanship models have received considerably more attention and empirical support than electoral cycle models. Leading scholars, such as Alberto Alesina and Douglas Hibbs, have argued that partisanship is the most fundamental basis for political influence over macroeconomic policy and outcomes. There are, indeed, systematic partisan differences, but economic movements are so fluid that party differences are often overwhelmed by larger tides of change. A limitation in most of the existing studies of macroeconomic partisanship is that they have assumed that party differences regarding goals have remained fixed or constant. That assumption has rarely been documented or tested, and I will argue that partisan goals are, in fact, variable. Even fixed goals may be relaxed under certain circumstances that make them unusually costly, but I contend that partisan goals are themselves variable, subject to conditions that are still only poorly understood.

Also, the institutional framework in which American parties operate is not constant. Changes in the institutions in which fiscal and monetary policies are made are likely to affect the implementation of alternative partisan goals, even if those goals were to remain constant (see Chapters 8 and 9). Most of the empirical demonstrations of partisan differences have focused on presumably fixed differences between the Democratic and Republican Parties regarding control of the presidency. But a growing literature has argued that other patterns of variations in the control of office are also consequential. Most prominently, divided partisan control of the presidency and Congress can affect policy outcomes. Outside the United States, partisan competition is made more complicated in many democratic countries by the continuing presence of more than two parties. A two-party system that offers only dual alternatives is, by comparison, a radical simplification of the actual possibilities.