Youth curfews are also logical. If youngsters are getting into trouble, it makes sense to get them off the streets.
There's only one problem with youth curfews: They don't work. And we shouldn't kid ourselves that they do.
Yet that's what we're doing in Philadelphia, where Mayor Nutter recently extended a 9 p.m. curfew on Friday and Saturday nights for all unaccompanied minors in Center City and University City. The measure came on the heels of this summer's violent flash-mob episodes, which seem to have quieted down since then.
But the city already had a youth curfew in place, long before the flash-mob mayhem began. On weekdays, it's 9 p.m. for children under 13 and 10:30 p.m. for children 13 to 17; on the weekends, everyone has to be home by midnight.
And that hasn't done anything to stem the tide of youth violence in Philadelphia. Insofar as the downtown curfew has "worked," it probably just displaced crime from one part of the city - and one time of the day - to another.
That's what happened in Detroit, after it adopted a youth curfew in 1976. Juvenile crime dropped 6 percent during the curfew hours, but it increased 13 percent in the midafternoon. Nationwide, more than 80 percent of juvenile offenses take place between 9 a.m. and 10 p.m. - outside most curfews.
Nor do we have any solid evidence that youth curfews lower the overall rate of juvenile crime. In a close study of Monrovia, Calif., in the 1990s, for example, sociologist Michael Males found that juvenile arrests for non-curfew crimes increased 53 percent during the school months when the town's curfew was enforced. In July and August, when the curfew was not enforced, non-curfew youth crime went down 12 percent.
So why are we so wedded to youth curfews? The answer has less to with youth than with adults. Whenever we get worried that the youth are