Fluctuating input prices are shown to cause greater variability in the profits of monopolies than of competitive firms. Hence monopolies have greater incentives to hold input stocks and participate in futures markets than do competitive firms.

Costs must be incurred if an owner is to enforce private property rights effectively. We show that, in a perfectly competitive economy, private decisions to enforce rights may result in either more or less enforcement than is socially efficient. Cases of multiple stable equilibria occur, and an equilibrium may be locally, but not globally, efficient. Resources may not be employed in their socially most valuable uses, and enforcement may be accompanied by inefficient investment in resource productivity.

Costs must be incurred if an owner is to enforce private property rights effectively. We show that, in a perfectly competitive economy, private decisions to enforce rights may result in either more or less enforcement than is socially efficient. Cases of multiple stable equilibria occur, and an equilibrium may be locally, but not globally, efficient. Resources may not be employed in their socially most valuable uses, and enforcement may be accompanied by inefficient investment in resource productivity.

Distributions of income are compared under the alternative regimes of free access to, and private property in, a resource. It is shown that, in several analytically distinct cases, all those deprived of free access on conversion of a resource to private property can be better off, even though no compensating transfers are made. This resu lt can hold even if the granting of private property rights also conf ers monopoly or monopsony power.

Fluctuating input prices are shown to cause greater variability in the profits of monopolies than of competitive firms. Hence monopolies have greater incentives to hold input stocks and participate in futures markets than do competitive firms.