We are frequently told that America should be ashamed of having sent so many people to prison. We are compared unfavorably to most of Europe. But these complaints rarely ask what benefits flow from prison.
The best scholars have estimated that between 25 and 30 percent of the recent decline in crime rates is the result of imprisonment. A comparison with England is helpful. At one time it imprisoned a higher fraction of offenders than did the US, but in the 1980s it changed by imprisoning fewer people. As a result (I think), the British crime rate soared while ours fell.
Between 1980 and 1985 the American prison population increased by more than half and between 1985 and 1990 it again increased by half. But from 1987 to 1992, the British prison population dropped by about five thousand inmates despite a sharp rise in the crime rate.
These different responses did not happen by accident. Americans, voting for district attorneys, mayors, and governors, chose people who would take crime seriously. In England hardly any of these offices are filled by local election; instead, the Parliament and the Home Office decide on crime policies.
Those decisions included a bill that urged judges not to send offenders to prison unless the crime was very serious, and in determining seriousness the judges were asked to ignore the prior record of the offenders.
In short, American policies were driven by public opinion while British ones were shaped by elite preferences. As a result, victim surveys show that by the late 1990s the British robbery rate was one-quarter higher and the burglary and assault rates twice as high as those in this country.
This raises the interesting question of why elite views should be so different from popular ones. Some possible explanations: Elites can more easily protect themselves from criminal attacks; elites tend to have a therapeutic rather than punitive view of crime; elites in parliamentary regimes are protected against sharp swings in public moods.
There are a lot of criticisms one can make of prisons, but sending offenders there, provided it is done correctly and without abuse, is an eminently democratic strategy: We deprive guilty people of liberty to make innocent people safer.