The Tragedy of the Commons and Socialization: Theory and Policy

We revisit the Tragedy of the Commons in an dynamic overlapping generations economy peopled of shepherds who decide how many sheep they let graze on a common parcel of land, while relying on di fferent forms of rationality (Nash players, Pure or Impure Kantian players). We examine the dynamics of heterogeneity and land congestion when the prevalance of those di fferent forms of rationality evolves over time follow- ing a vertical/oblique socialization process a la Bisin and Verdier (2001). We study the impacts of a quota and of a tax on the congestion of land, and we show that introducing a quota may, in some cases, reduce the proportion of Kantians (Pure and Impure), and worsen the Tragedy of Commons with respect to the laissez-faire. Finally, we examine whether a government should promote either a Pure or an Impure Kantian morality, by comparing the relative fi tness of Pure/Impure Kantians, and their interactions with the congestion of land.