Between selfishness and altruism: Fuzzy Nash-Berge-Zhukovskii equilibrium

Abstract

Nash equilibrium in many cases is not the best choice for human players. In case of trust games the Nash equilibrium is often mutual defection which is the worst possible outcome for all players. The Berge-Zhukovskii equilibrium models a more cooperative behavior, so in case of trust games, when players gain by cooperating, it is usually a better choice than Nash equilibrium. Real life results show that players rarely follow the theoretical predictions. Our aim is to find new equilibria types that offer a more realistic modeling of human players. The fuzzy Nash-Berge-Zhukovskii equilibrium is proposed which is a fuzzy combination of the Nash and Berge-Zhukovskii equilibrium. Several continuous trust games are investigated. Numerical results indicate that fuzzy Nash-Berge-Zhukovskii equilibrium is suitable to model real-life situations. © 2012 Springer-Verlag.