We present a model which ties together rational drug consumption, taxation, crime and other drug-related externalities. Drug control policy is addressed using an optimal tax framework. Consumption, possession and production of a drug may be prohibited, legalized or decriminalized. In all regimes illicit production of a drug may take place and drug-related crime occurs. We show that illicit drug production, the price elasticity of demand for a drug, the addictive nature of a drug, the effectiveness of drug enforcement strategies, and income distribution all influence optimal (second best) policy. Prohibition is contrasted with decriminalization and legalization, and where legalization yields a higher welfare than prohibition we show that this can be associated with greater drug-related crime and more drug addiction. The model is discussed in the context of US National Drug Control Strategy
