We demonstrate how altruism can surge in a population of nonaltruists. We assume that each individual plays a one-shot prisoner's dilemma game with his or her sibling, or with a stranger, and that the probability that an individual survives to reproduce is proportional to his or her payoff in...

Recent research shows that the merger of economies increases aggregate stress. This paper shows that there is no income distribution policy which will ensure that the wellbeing of the individuals belonging to merging economies does not fall below their pre-merger level.

We relate to others in two important ways: we care about others, and we care about how we fare in comparison to others. In some contexts, these two forms of relatedness interact. Caring about others can conveniently be labeled altruism. Caring about how we fare in comparison with others who fare...

We provide an analytical-behavioral explanation for the observed positive relationship between income inequality, as measured by the Gini coefficient, and the incentive to migrate. We show that a higher total relative deprivation of a population leads to a stronger incentive to engage in...

Illegal migrants supply a valuable productive input: effort. But their status as illegals means that these migrants face a strictly positive probability of expulsion. A return to their country of origin entails reduced earnings when the wage at origin is lower than the wage at destination. This...