In the United States over the past 20 years, crime rates have fluctuated but have done so around a fairly stable mean. During the same period, the incarceration rate grew exponentially. Crime control theory suggests that, if punishment levels increase, deterrence and incapacitation should show themselves in a corresponding reduction in crime rates. One explanation for the apparent discordance between the crime and incarceration trends is the incarceration worked; it prevented an increase in crime that otherwise would have occurred. In addition, it is important to consider the effect of drug arrests on prison populations. Drug offenses increased tenfold during the period 1980-1995. If drug offenders engaged in a variety of other crimes, one might anticipate a drop in the rates of those crimes while the drug offenders are in prison. The article suggests the need for further research into the crimes averted through the growth in incarceration and of the counterproductive consequences of incarceration. Figures, references