Price controls could have a substantial negative effect on pharmaceutical research and development. Extensive research is required before the development costs of a new drug or its benefits are known; most new drug development projects fail, sometimes after substantial financial and time costs. These conditions pose intractable practical problems for the operation of price controls, which cannot rest on objective, predictable standards such as the benefits or costs of individual drugs. In the absence of objective standards, pressure from health care providers and others would create powerful incentives for price regulators to decrease drug prices toward marginal costs of production and distribution, well below levels sufficient to reward innovative research. This downwardly biased price-setting mechanism would apply with particular force to the few successful projects that yield innovative drugs, whose prices would not be set by regulatory authorities until after research expenditures have been incurred and the new drugs are ready to enter the market. Manufacturers will expect price controls to reduce the potential payoffs from breakthrough drugs. This expectation would substantially reduce the incentives to pursue innovative research, as is evident in advanced economies in which price controls are now in force. Once established, price controls for pharmaceuticals, like those for medical services in the Medicare system, would also tend toward complexity and entrenchment of vested interests and could easily become permanent regardless of the harm they cause to patients.