RIEB, Kobe University

On Coalitional Stability and Single-peakedness

We study a one-dimensional voting game in which voters choose a policy from a one-dimensional policy set over which voters have single-peaked preferences. The purpose of this paper is to analyze coalitional behaviors under any given voting mechanism. We employ the notion of strong Nash equilibrium and identify a necessary and sufficient condition for a voting mechanism to possess a strong Nash equilibrium by using the minimax theorem. We moreover show that any strong Nash outcome, if it exists, results in an outcome recommended by a particular augmented median voter rule.