Trust,assurance, and inequality: A rational choice model of mutual trust 1

The rational choice approach to trust has three problems: it has not explicitly explained findings verified in social psychological study of trust; it stands on a limited assumption of asymmetric relationship between a truster and a trustee; and it has not dealt with situations in which a rich person encounters a poor person. We build a game theoretic model of mutual trust to solve these problems. Then we analyze an equilibrium of the model and derive some implications from it. That is, the ratio between the transaction costs and the opportunity costs affects actor' trustfulness; a more trustworthy actors finds it easier to leave his/her group in search of higher returns; and a rich actor is more willing to trust his/her counterpart than a poor actor.