A program of “swift-certain-not-severe” sanctions can work, by giving each offender a clear and explicit warning of exactly what’s going to happen every time he gets caught breaking a rule, Mark Kleiman of the UCLA School of Public Affairs writes in the Washington Monthly. The best-publicized program built on these principles is HOPE in Honolulu, which requires random drug tests of probationers and, for those who fail, an immediate short stint in jail, with no exceptions. The SWIFT program in Texas, WISP in Seattle, the Swift and Sure program in Michigan, and Sobriety 24/7 in South Dakota all work the same way, and all have the same results: drastic reduction in illicit-drug use (in the case of 24/7, alcohol abuse), reoffending, revocation, and time behind bars.

There’s nothing surprising about the fact that this approach works—it’s the application of well-known behavioral principles to a fairly straightforward problem, Kleiman says. What is surprising is how well it works. In Hawaii, HOPE clients are mostly longtime criminally active drug users with a mean of seventeen prior arrests. A drug treatment program would be delighted if it could get 20 percent of such a population into recovery—and most would quickly drop out and go back to drug use. In a carefully done randomized controlled trial with 500 subjects, eight out of ten assigned to the HOPE program finished the first year of the program in compliance and drug free for at least three months, with no rearrest.