Elections and Durable Governments in Parliamentary Democracies

This paper provides a theory of a parliamentary government system with proportional representation elections and policy-motivated parties and voters. In a symmetric, spatial model governments are majoritarian, they and their policies are durable, and voters elect minority parliaments in every period. A continuum of (Markov) political equilibria exist with policies that represent concessions to centrist voters. In these equilibria the government parties have equal representation and are equal partners. The greater the concession the more politically patient the parties must be for an equilibrium to exist. If one party is more centrally-located in the space of voter preferences, it can receive a majority and choose its ideal policy. If reallocable officeholding benefits are available, the policy of a durable government favors the leader of government and changes when the leader changes. In the elections the out party loses half its vote share to one of the government parties. If crises can occur, governments can fall, but a new government forms after the next election. If crises are sufficiently likely, no political equilibrium exists. The theory provides explanations for three empirical findings: a Gamson’s law for a spatial model, an analogue of Duverger’s law for proportional representation electoral systems, and compensational voting where voters give the out party additional votes. ∗655 Knight Way, Stanford CA 94305. [email protected]. (650)723-3757 (P), (650) 724-9649 (F).