Ross says folks who'd like to see the US move to a more humane criminal justice system can't beat something with nothing, and had better propose an alternative means of getting the crime-control effects of mass incarceration. His idea: more cops on the beat:
One possible answer, I think - again, drawing a bit from The Wire as well as from public policy research - is more cops on the beat. This could be the twofer that (right-wing) prison reformers offer skeptical voters: Lighter sentences and more emphasis on rehabilitation on the one hand, and larger, more active police forces to pick up the slack (and ideally gain even more ground) on the other.
I think there's a lot to that. Even better in some ways, though not as good in political terms, would be to have more parole officers. A year on parole is obviously far more humane than a year in prison. And even a closely monitored parolee is less expensive than an additional prisoner. But a well-designed parole system can have almost as much crime control oomph as more prison beds. The trick is that it only works if you put enough money into hiring parole officers that they can really monitor their parolees. Right now, the system depends very heavily on infrequently enforced but very severe sanctions for, e.g., people who fail drug tests. With more resources you could switch that around to a much more effective system with less severe penalties but a higher cost of getting caught.