A Model for ``The Tragedy of the Commons´´

A formal dynamic model which represents the assumptions in Hardin´s paper, ``The Tragedy of the Commons,´´ exhibits his conclusions explicitly. The calculus serves as an adequate language for the model, but its conclusions are exhibited graphically with the aid of a simulation language and computation. Technological solutions to the ``tragedy´´ necessarily fail; coercive solutions admit a range of possibilities. Limitation of the use of the ``commons´´ may prove more successful than taxation for the use of the ``commons.´´ The model lays both assumptions and conclusions open to critical examination, and serves as a useful teaching tool.