In “Eldred and Fair Use,” Posner comments that awarding a monopoly over Mickey Mouse avoids the congestion problem that occurs with open access highways. Is the public domain a commons like an open access highway? No, it is not.

In this paper I consider an OLG model with production and a single commodity. I show that in such an environment unbounded growth of income per capita is not possible if the aggregate technology is of the usual constant returns to scale type. This is not due to lack of productivity of the...