Tragedy of the commons
A resource that everyone may draw on and nobody may exclude others from is used past the point that would suit the users collectively, because each one bears only a share of the damage they do.
Often misread asConcluding that the only remedies are private ownership or state control, which is the version of the argument Ostrom spent a career documenting counterexamples to.
How to see it
Whole gain to you, a fraction of the cost
A resource anyone may use and nobody may be kept out of gets used well past the point that would suit the users as a group. Each extra unit taken is a full gain to the taker and only a fraction of a loss, because the depletion is spread over everyone. Each person's arithmetic is correct and the total is a disaster.
The checkCommunities have repeatedly managed shared resources with their own monitoring and sanctions. What is needed is some way to exclude or to punish overuse, and ownership is one option among several.
Try itTwenty boats share a fishery. Work out what one boat gains from one extra day out, and what share of the resulting depletion it bears. Then ask what would have to change for that comparison to flip, and notice that a binding local agreement would do it without anybody owning the sea.
Games that show it
Know these first
Easily confused with
Sources
- Hardin, G. (1968). Science 162(3859), 1243-1248.
- Ostrom, E. (1990). Cambridge University Press.