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 swappingʺ individuals between heterogeneous groups of constant size after a random allocation fills the haystacks,...

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 prisoner's...

Let a society’s unhappiness be measured by the aggregate of the levels of relative deprivation of its members. When two societies of equal size, F and M, merge, unhappiness in the merged society is shown to be higher than the sum of the levels of unhappiness in the constituent societies when...

This paper asks whether population growth is conducive to the sustainability of cooperation. A simple model is developed in which farmers who live around a circular lake engage in trade with their adjacent neighbors. The payoffs from this activity are governed by a prisoner's dilemma "rule of...

I study the integration of regions in the form of a merger of populations, which I interpret as a revision of people's social space and their comparison set; I illustrate the way in which a merger can aggravate social distress; and I consider policy responses. Specifically, I view the merger of...

In this paper I study policy responses to an increase in post-merger distress. I consider the integration of regions and nations as a merger of populations which I view as a revision of social space, and I identify the effect of the merger on aggregate distress. The paper is based on the premise...

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 two...

We calculate the equilibrium fraction of cooperators in a population in which payoffs accrue from playing a single-shot prisoner's dilemma game. Individuals who are hardwired as cooperators or defectors are randomly matched into pairs, and cooperators are able to perfectly find out the type of a...

The merger of populations expands the comparison space of incomes. As a result, measures of the income-based social stress and of the income inequality of the constituent populations need to be replaced by new measures. To this end, we develop a procedure for calculating the aggregate social...