In 1968, the American ecologist Garrett Hardin wrote “The Tragedy of the Commons” which must be the most cited article ever to appear in Science Magazine. In this article, Hardin described the “tragedy” associated with common pool resources—those that are claimed or used by many with little effective restriction. With a common resource, each party is motivated by private self-interest in deciding how much of and when to use the resource. But the costs of these private decisions are spread across to everyone. This mismatch between private and social benefits and costs in decision-making results in the outcomes we are all familiar with—waste, plundering, and extensive and rapid use of the resource with little consideration of the future.
Hardin made his point by describing a pasture that was “open to all” and, hence, subject to overgrazing. Although each herder privately benefits from grazing his or her own animals, the costs of overstocking are shared by all herders. Under these circumstances, each herder is motivated to add more animals than would be optimal for the range resource. Hardin concluded: “Therein is the tragedy. Each man is locked into a system that compels him to increase his heard without limit—in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons.”