Interesting thought experiment over at the Volokh Conspiracy, “What would the world look like if, instead of assigning prisoners to particular prisons bureaucratically, we gave them vouchers, good for one incarceration, that they were required to redeem at a participating prison?”

The idea patterns itself after school vouchers.  Different students have different educational needs, and different prisoners may have different security and rehabilitation needs.

Prisons could adapt to different kinds of rehabilitation, including drug rehabilitation, religious emphasis, etc.