Markets for illicit drugs present an interesting case study for economics, combining non-standard characteristics such as addiction and product illegality. One response has been to argue the generality of economic principles by suggesting that they apply even in the extreme case of markets for...

The standard model of markets for illicit drugs predicts that tougher enforcement against sellers will raise prices; yet cocaine and heroin prices have fallen substantially during a period of massive increases in enforcement. We present a model in which the basic mechanisms at work in the...