Transboundary Environmental Problems with Mobile but Heterogeneous Populations

Most of the literature on transboundaryenvironmental problems treats population ineach country or region as constant, ignoringpopulation mobility. We showed previously thatif there is perfect population mobility betweenregions, and populations are homogeneous, asocially efficient outcome can be supported asa Nash equilibrium of the game of uncoordinatedpolicy setting, even without any internationalenvironmental agreement. In the present paperwe introduce heterogeneous population, and showthat when people differ, a non-cooperativeoutcome is generally inefficient. We alsodemonstrate that for a particular set ofobjective functions for the regionalgovernments, there is an equilibrium of thegame of uncoordinated policy setting that isefficient. Finally, we give an example wherethe decentralized outcome is efficient whenthere is no population mobility, butinefficient when there is population mobility.