Fundamentals of Social Choice Theory

This paper offers a short introduction to some of the fundamental results of social choice theory. Topics include Nash implementability, monotonic social choice correspondences, the Muller-Satterthwaite impossibility theorem, anonymous and neutral social choice correspondences, sophisticated solutions of binary agendas, the top cycle of a tournament, the bipartisan set for two-party competition, and median voter theorems. The paper begins with a simple example to illustrate the importance of multiple equilibria in game-theoretic models of political institutions.