Most societies rely on competitive markets to handle the allocation of scarce resources to their highest and best uses. Yet markets are not without their shortcomings. For this reason, governments sometime institute regulatory control. In 1887, the first regulatory agency, the Interstate Commerce Commission, was created to regulate monopolistic pricing policies of railroads.

When private firms gain monopoly power, usually because of economies of scale, they are in a position to restrict production and raise price with little worry of competition; these are known as natural monopolies. The government may permit a single producer (e.g., of natural gas or electricity) to exist in order to gain lower production costs but simultaneously empower a regulatory agency to set the firm's prices.

A second reason for regulation stems from the fact that society declares certain activities illegal. Prostitution, gambling, and certain drugs are either not permitted or allowed only under...