A utilitarian social planner who maximizes social welfare assigns the available income to those who are most efficient in converting income into utility. However, when individuals are concerned about their income falling behind the incomes of others, the optimal income distribution under...

This paper considers a setting in which the acquisition of human capital entails a change of location in social space that causes individuals to revise their comparison groups. Skill levels are viewed as occupational groups, and moving up the skill ladder by acquiring additional human capital,...

This paper develops a one sector, two-input model with endogenous human capital formation. The two inputs are two types of skilled labor: engineering, which exerts a positive externality on total factor productivity, and law, which does not. The paper shows that a marginal prospect of migration...

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...

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...

A migration network is modeled as a mutually beneficial cooperative agreement between financially-constrained individuals who seek to finance and expedite their migration. The cooperation agreement creates a network: established migrants contract to support the subsequent migration of others in...

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 dilemma...

Recent analyses of the evolution and structure of trade in virtual water revealed that the number of trade connections and volume of virtual water trade have more than doubled over the past two decades, and that developed countries increasingly draw on the rest of the world to alleviate the...

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 identifies the migration policies that emerge when both the sending country and the receiving country wield power to set migration quotas, when controlling migration is costly, and when the decision how much human capital to acquire depends, among other things, on the migration...