Suppose that fishermen have unlimited access to a pond of fish. The market for fish is competitive, so fishermen take the price as given.

Suppose that fishermen have unlimited access to a pond of fish. The market for fish is competitive, so fishermen take the price as given. The fishermen face a private marginal cost, but do not consider the additional cost of depleting the stock of fish in the pond. Graph the demand, private cost, and marginal social cost for fish from this pond, showing the efficient quantity, the actual quantity, and the social cost of common access.