Heroin and Cocaine Price Changes and Polydrug Use

This paper studies polydrug use patterns in heroin and cocaine addicts. We use data on two experiments to measure the elasticity of several addictive drugs with respect to heroin and cocaine prices. Own and cross price elasticities are estimated while controlling for non-price related sources of variance. The results indicate that heroin addicts have an inelastic demand for heroin, complement heroin consumption with cocaine, marijuana, and alcohol, and substitute Valium and cigarettes for heroin. Additionally, heroin addicts have an inelastic demand for cocaine, and they complement cocaine with heroin and alcohol, and substitute it for marijuana, Valium and cigarettes. Cocaine addicts have an elastic demand for cocaine, they complement cocaine with heroin and they substitute it for marijuana, alcohol and cigarettes. Cocaine addicts’ demand for heroin is negatively affected by heroin prices; in this group, cocaine and cigarettes are a complement to heroin, and marijuana, alcohol, and Valium are substitutes 1 London School of Economics and King’s College. 2 Alcohol Research Center, Department of Psychiatry University of Connecticut Health Center, Farmington, CT, USA.