In a haystack-type representation of a heterogeneous population that is evolving according to a payoff structure of a prisoner’s dilemma game, migration is modeled as a process of “swapping” individuals between heterogeneous groups of constant size after a random allocation fills the...

Quite often, migrants appear to exert little effort to absorb the mainstream culture and to learn the language of their host society, even though the economic returns (increased productivity and enhanced earnings) to assimilation are high. We show that when interpersonal comparisons affect...

Consider a population of farmers who live around a lake. Each farmer engages in trade with his m adjacent neighbors, where m is termed the “span of interaction.” Trade is governed by a prisoner's dilemma “rule of engagement.” A farmer's payoff is the sum of the payoffs from the m...