Pareto optimality in spatial voting models

Abstract

This paper studies the Pareto optimality properties of policy proposals that are made byk(k≧2) strategic candidates that face uncertainty about the choices that the voters will make. Our first theorem shows that, under very general conditions, any proposal that is a best reply for a candidate is necessarily Pareto optimal. This theorem, in turn, implies that, under slightly stronger conditions, all candidate proposals that are made in a Nash equilibrium or sequentially are necessarily Pareto optimal. Our second theorem shows that, when these conditions are themselves slightly strengthened, any proposal outside of the Pareto set is strictly dominated by at least one proposal inside the Pareto set.