The analysis particularly emphasizes the relationship between drug expenditures and earnings from crimes other than drug trafficking offenses. The model consists of four structural equations and four endogenous or jointly determined variables, which include income from selling drugs, income from all other criminal activity, income from legal activities, and dollar size of drug consumption. The evidence vis-a-vis the impact of drug abuse on criminal activity is considerably more subtle than suggested by previous research. In fact, the most significant relationship shows that criminal earnings being spent on drugs of abuse dominates the interdependency between drug use and crime. The impact of drug use on criminal activity is even less when other sources of income are considered. 4 tables, 9 notes, and 18 references