The Tragedy of the Commons, Revisited

In 1968, the ecologist Garrett Hardin published an influential essay describing what he called the tragedy of the commons. He asked readers to imagine a pasture open to all herders. Each herder gains the full benefit of adding another animal, while the cost of overgrazing is shared by everyone. Acting rationally, each herder keeps adding animals until the pasture is destroyed.

Hardin's argument was widely used to explain problems such as overfishing, air pollution, and the depletion of groundwater. His conclusion was stark: shared resources would inevitably be ruined unless they were either privatized or strictly controlled by governments.

The political scientist Elinor Ostrom challenged this pessimistic view. Studying fisheries, forests, and irrigation systems around the world, she found many communities that had managed shared resources successfully for generations without either privatization or heavy state control. What these communities had in common were clear boundaries, rules adapted to local conditions, monitoring by members themselves, and fair ways of resolving disputes. Her work earned her the Nobel Prize in economics in 2009, making her the first woman to receive it.

Ostrom's findings do not mean that the tragedy of the commons is a myth. Rather, they suggest that it is a risk, not a destiny. The challenge for problems such as climate change, which involve billions of people rather than a small village, is whether similar principles of trust, cooperation, and accountability can be scaled up to a global level.