Abstract:
It is proved for two-player normal form games that if a totally mixed Nash equilibrium exists then the entire set of Nash equilibria is (trembling-hand) perfect. More generally, it is proved that if there is a (trembling-hand) perfect equilibrium, then all Nash equilibria whose supports are contained in the perfect equilibrium's support are also perfect. The possibility of similar relationships in three or more player games and proper equilibria of two-player games is discussed.