The tragedy of the commons revisited

Abstract

The Malthus–Hardin tragedy of the commons is formulated as a dynamic game between “clans”. At each date a member of a clan desires more newborns of her/his type and more current consumption, harvested from the commons. Equilibrium in the dynamic game yields a steady state level of per capita consumption and a steady population level for each clan (births equal deaths). Four outcomes are obtained, depending on the assumptions about the discount rates of members of a clan and about the mode of competition for “large populations” for each clan. Lack of property rights for agricultural land in the commons leads to equilibrium with excessive populations and low per capita consumption.