Cooperating behavior may be fostered by personality traits re ecting either favorable inclination to others or willingness to comply with norms and rules. We test the relative importance of these two factors in an experiment where subjects provide real mental effort in two treatments with...

Cooperating and trusting behavior may be explained by preferences over social outcomes (people care about others, are unselfish and help- ful), or attitudes to work and social responsibilities (plans have to be carried out, norms have to be followed). If the first hypothesis is true, Agreeable-...

Informal, kin-based groups play an important role in developing country economies. I point out two facts: communities are divided into smaller groups, and many groups prohibit interactions with outsiders. These facts are rationalized in a model in which division of the community into...

This research advances the hypothesis that reversal of fortunes in the process of economic development can be traced to the effect of natural land productivity on the desirable level of cooperation in the agricultural sector. In early stages of development, unfavorable land endowment enhanced...

Cooperating behavior may be fostered by personality traits reflecting either favorable inclination to others or willingness to comply with norms and rules. We test the relative importance of these two factors in an experiment where subjects provide real mental effort in two treatments with...

Many societies are divided into multiple smaller groups. The defining feature of these groups is that certain kinds of interaction are more likely to take place within a group than across groups. I build a model in which group divisions are enforced through a reputational penalty for interacting...

We present a dynamic model of jurisdiction formation in a society of identical people. The process is described by a Markov chain that is defined by myopic optimization on the part of the players. We show that the process will converge to a Nash equilibrium club structure. Next, we allow for...