Violence and the U.S. Prohibition of Drugs and Alcohol

Among the many unresolved questions regarding the determinants of violence is the role of prohibitions against drugs and alcohol. Conventional wisdom holds that consumption of these goods encourages violence and that prohibitions discourage such consumption; thus, prohibitions reduce violence. An alternative view, however, is that prohibitions create black markets, and in black markets participants use violence to resolve commercial disputes. Thus, prohibitions potentially increase violence. This paper examines the relation between prohibitions and violence using the historical behavior of the homicide rate in the United States. The results document that increases in enforcement of drug and alcohol prohibition have been associated with increases in the homicide rate, and auxiliary evidence suggests this positive correlation reflects a causal effect of prohibition enforcement on homicide. Controlling for other potential determinants of the homicide rate -- the age composition of the population, the incarceration rate, economic conditions, gun availability, and the death penalty -- does not alter the conclusion that drug and alcohol prohibition have substantially raised the homicide rate in the United States over much of the past 100 years.