The median and the competitive equilibrium in one dimension

Two alternative models of legislative outcomes are the minimum winning coalition and the competitive equilibrium (Koford, 1982). In a unidimensional setting, the outcome under the former is the median, while the outcome under the latter is the highest net demand location.This paper describes the competitive equilibrium in a unidimensional model, and shows that under some common conditions it coincides with the median, in particular for pure redistributive issues. However, for distributive issues, the two equilibria will differ. Finally, the comparative statics of the two models are examined; while the winning coalition is sensitive only to changes in the location of the median, for distributive issues the competitive equilibrium has the standard economic comparative statics that the outcome adjusts in the direction of the change in preferences.