A model of endogenous political party platforms

We develop a model of endogenous party platform formation in a multidimensional policy space. Party platforms depend on the composition of the parties’ primary electorate. The overall social outcome is taken to be a weighted average of party platforms and individuals vote strategically. Equilibrium is defined to obtain when no group of voters can shift the social outcome in its favor by deviating and the party platforms are consistent with their electorate. We provide sufficient conditions for existence of equilibria.Ortuño-Ortín gratefully acknowledge financial support from the Spanish Ministry of Science and Technology Project BEC2001-1653 and Project BEC2001-0980, respectively; A. Gomberg gratefully acknowledges the financial support from the Asociación Mexicana de CulturaPublicad