Most people imagine that the explosion in the U.S. prison population during the past twenty-five years reflects changes in crime rates. Few would guess that our prison population leaped from approximately 350,000 to 2.3 million in such a short period of time due to changes in laws and policies, not changes in crime rates. Yet it has been changes in our laws—particularly the dramatic increases in the length of our prison sentences—that have been responsible for the growth of our prison system, not increases in crime. One study suggests that the entire increase in the prison population from 1980 to 2001 can be explained by sentencing policy changes.

Michelle Alexander