Marijuana enforcement is intended to reduce consumption. By adding to the costs of trafficking in marijuana, enforcement increases its price. Some users will continue to buy as much marijuana as before, but others will cut back on their use in the face of higher prices or even stop use entirely. For those who continue to use marijuana, its higher cost creates financial problems and may lead to other criminal behaviors in an effort to support marijuana use. For those pressured to stop marijuana use because of the risk of arrest, other more dangerous drugs may be substituted. The criminalization of marijuana and the enforcement of proscriptive laws also creates an illicit marijuana market that brings certain consequences. These include violence and crime, the corruption of public officials, the demoralization of law enforcement and law-abiding citizens, an increase in the revenues of criminal organizations whose activities are not confined to handling marijuana, and complications in relations with foreign governments of source countries. 4 graphs.