A theory of divided government

This paper extends the spatial theory of voting to an institutional structure in which policy choices depend upon not only the executive but also the composition of the legislature. Voters have incentives to be strategic since policy reflects the outcome of a simultaneous election of the legislature and the executive and since the legislature's impact on policy depends upon relative plurality. To analyze equilibrium in this game between voters, we apply ''coalition proof' type refinements. The model has several testable implications which are consistent with voting behavior in the United States. For instance, the model predicts: (a) split-tickets where some voters vote for one party for president and the other for congress; (b) for some parameter values, a divided government with different parties controlling the executive and the majority of the legislature; and (c) the midterm electoral cycle with the party holding the presidency always losing votes in midterm congressional elections.