"General Political Equilibrium in Parliamentary Democracies"

Kalandrakis, Anastassios

akalandr@ucla.edu

 Prepared for delivery at the 1999 Annual meeting of the American 
Political Science Association, Atlanta Marriott Marquis and Atlanta 
Hilton and Towers, September 2-5, 1999.

Abstract:

I propose a model of parliamentary democracy in which voters are 
motivated by policy outcomes while individual representatives' 
utility also depends on elective office. The number and policy 
preferences of parties are determined endogenously by the 
equilibrium distribution of individual representatives across 
parties. I study symmetric cutoff-point Nash equilibria of this game 
and show that the distribution of policy outcomes is more centrally 
concentrated under a Three-Party than under a Two-Party equilibrium. 
Three-Party equilibria only emerge when there is positive 
probability of a Minority government, and only centrally located 
parties form such governments. A Two-Party equilibrium always exists 
(Duverger's Hypothesis). So does a Dominant Party equilibrium, where 
the centrist party receives a majority of legislative seats. The 
existence of a Three-party equilibrium depends -- apart from the 
Electoral rule -- on the Selection process at the government 
formation stage, and the magnitude of the overall utility from 
control of cabinet positions relative to the policy space. Along 
with Duverger's mechanical and psychological effects, electoral 
disproportionality induces an indirect representative adjustment 
effect, whereby voting behavior is altered due to changes in the 
composition of political parties.