Efficient property rights systems have four characteristics:
1. Universality: All resources are privately owned.
2. Exclusivity: Benefits and costs of resources accrue only to their owners.
3. Transferability: Property rights must be freely transferable between people.
4. Enforceability: Property rights should be protected from seizure or encroachment.
Private property rights are fundamental preconditions for the existence of market economies.
Resources generate Ricardian scarcity rents which can also be viewed as opportunity costs: allocation of a unit of resource to any one use precludes other uses of it; use of a unit of resource at any one time period precludes using it in any other time period. These opportunity costs are sometimes referred to as "marginal user costs."
Mainstream microeconomic theory assumes perfect markets (many buyers and sellers, full information precluding price discrimination, etc.) that achieve Pareto-optimal outcomes. However economists have identified various categories of market failure, where violations of one or more key assumptions of the perfect market model prevent markets from achieving a Pareto-optimal outcome. Market failures arise in cases of...
• externalities
• common property resources
• public goods
• imperfect markets
• diverging social and private rates of discount
• government failure
Externalities
An externality occurs when one party generates costs or benefits for some other party but doesn't account for those costs or benefits. A positive externality generates an inadvertent benefit for someone else: for example, in the process of making honey for himself, a bee-keeper's bees pollinate neighboring crops, improving crop yields on neighboring farms, although the farmers don't share the benefits of the higher yields with the bee-keeper. A negative externality generates an inadvertant cost for other people: for example, a paper mill dumps pollutants upstream from a trout hatchery and reduces the hatchery's productivity, but doesn't account for the damages to the hatchery in its own accounting.
An pollution externality increases the social costs of production beyond the private costs borne by the firm. In the graph below, a firm's output generates a pollution by-product. Without controls, this firm produces to the point where its marginal private cost equals its marginal revenue (Demand). The firm enjoys free use of the environment for waste disposal; the environmental costs are borne by society. Thesocial optimum is where the marginal social cost (marginal private cost plus marginal pollution damage cost) equals marginal revenue (Demand). The social optimum level of the firm's output Q* is less than the private optimum level Q'. The social optimum price per unit P* is higher than the private optimum price P'.