The American incarceration rate is not only the highest it has ever been, but it is arguably the highest in the world-and not just by comparison to developed G8-type countries. With the possible exception of China, where “administrative detention” is the large, mysterious factor that makes published imprisonment numbers suspect, the United States stands alone in the world.

The sheer numbers-two-thirds of 1 percent of Americans are now serving jail or prison sentences-are embarrassing enough, especially because of their racial disproportion. But things are worse than the sheer numbers. We do not have enough space for the prisoners we incarcerate, and we mismanage their time and their transition back into society so badly that the potential crime-reducing effects of prison are blunted. True, the crime rate has dropped significantly in the last decade, but statistical experts observe that the huge jump in incarceration in recent years gets only fractional credit for that success-even before we account for other costs it may impose.