Modeling the response of illicit drug markets to local enforcement

Local-level enforcement has been cited as an effective drug enforcement strategy by some policy makers and experts. A more intensive tactic, with focus on a specific target area and referred to as "crackdowns", has been implemented in some cities. In this paper, we analyze a mathematical model due to Caulkins, to study the effect of focussed enforcement on drug markets. Specifically, we consider both fixed and dynamic enforcement policies. Our analysis suggests that drug dealing can be effectively controlled only if enforcement resources exceed a certain threshold level, and that the success of a crackdown operation may be lost fairly quickly if care is not taken to prevent the market from returning. This should provide enforcement officials with analytically derived "rules of thumb" to help make improved policy decisions.