First, one must think counterintuitively. Can one suppose that the overcrowding is functional? Can one suppose that the mandatory sentence laws operate exactly as intended and that the appropriate response now is to construct more prisons and add more juries? This may be similar to the effects of congestion costs on highways, according to economic theorists, in which drivers often react rationally and behave differently in response to major congestion, taking mass transit or driving at different hours. Following this analogy, at least one possible thesis is that fear of prison conditions will cause potential drug offenders to think twice before consuming and ending up in the criminal justice system. In short, suppose that the consequences are not unintentional but exactly as predicted? California officials make this argument in citing the 4.2% drop in violent crime and the 12% drop in the overall crime rate in a six-month period (The Economist 1998a). The rate of violent crime in the United States has fallen each year from 1991, dropped 7%in 1996, and is now at its lowest level in ten years (The Economist 1997b