THE PURPOSE OF PRISONS

The number of adults in the correctional system reached a record 6.47
million last year, more than 3 percent of the adult population. Whether you
consider this cause for alarm or encouragement depends on whether you
understand that while a criminal is behind bars he isn't committing crimes.

The fact that the proportion of adults incarcerated, on probation or on
parole has tripled since 1980 has the root-causers fretting.

"It's just overwhelming," said Kara Gotsch of the American Civil Liberties
Union. "It just shows we need to put much more into prevention," by which
she probably means the usual social programs.

But only those blinded by dogma could fail to see the correlation between
the increase of the prison population and the dramatic decline in crime
rates over the past decade. The murder rate, for instance, fell 50 percent
in the 1990s.

Career criminals commit dozens of crimes in the course of a year. By simply
keeping them out of circulation, there will be fewer robberies, rapes and
assaults. The Justice Department's Bureau of Justice Statistics found that
among those released from supervision in 2000, 42 percent of parolees were
back in prison for a new offense within a year. If parolees who committed
crimes but weren't caught were included, the total likely would exceed 50
percent. This confirms the wisdom of jailing them in the first place.