In the tragedy of the commons game, students act as fishermen and simultaneously decide how many hours to fish. A fisherman’s catch depends on the number of hours he fishes and the total number of hours fished by all. The more the group fishes, the more the available stock of fish diminishes and the fewer fish one can catch each hour.
Teach students about common pool resources and how self-interested use can cause harm to others (by creating negative externalities) and result in a tragedy of the commons. Explore how regulations, such as taxes or subsidies, can mitigate the over-use of natural resources.
In this game, the fishery returns to full health after each period, so the societal cost of overfishing is borne in the current period: the overall level of fishing this period determines the returns from an hour fishing. For a game where over-exploitation of a common-pool resource this period reduces future ability to benefit from a common-pool resource, see MobLab&rsqup;s Commons: Fishery game.