Replaced with revised version of paper 02/27/08.

Consider a population of farmers who live around a lake. Each farmer engages in trade with his two adjacent neighbors. The trade is governed by a prisoner’s dilemma “rule of engagement.” A farmer’s payoff is the sum of the payoffs from the two prisoner’s dilemma games played with his...

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...