Economics focus: Commons sense

摘要

In 1968 Garrett Hardin, a professor of biology, published an article in the journal Science that was to have a profound impact on the social sciences, including economics. In it, he explained "The Tragedy of the Commons". "Picture a pasture open to all," he wrote. A herdsman grazing his animals on the land will have an incentive "to add another animal to his herd. And another; and another.. .But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy." Each herdsman captures all the benefit from an extra animal but the cost of overgrazing is borne by all.