The Tragedy of the Commons

In 1968, the ecologist Garrett Hardin published an essay describing what he called “the tragedy of the commons.” He asked readers to imagine a pasture that is open to all the herders in a village. Each herder receives the full benefit of adding another animal to the field, while the cost of overgrazing is shared by everyone. As a result, every individual has a reason to add more animals, and the pasture is eventually destroyed.

Hardin argued that shared resources such as fisheries, forests, and clean air are vulnerable to the same pattern, and that the only solutions were government regulation or private ownership. His essay became extremely influential, but later research challenged its pessimism. The political scientist Elinor Ostrom studied communities that had managed common resources successfully for centuries, from mountain pastures in Switzerland to irrigation systems in Nepal.

Ostrom found that such communities typically shared several features. Users helped create the rules, could observe one another's behavior, and applied gradually increasing penalties to those who broke the rules. Her work, which earned her the Nobel Prize in economics in 2009, suggested that the tragedy Hardin described is not inevitable. Under the right conditions, people can cooperate to protect resources that no single person owns.