I beg to differ. US prisons are geared toward warehousing offenders and the punishment of them, not toward rehabilitation. I submit the following:
1) Rehabilitation is a *personal* decision. The offender has to actively decide to behave differently and has to do so on an on-going, moment-to-moment. The only thing a prison can do here is motivate a prisoner to make, and continue to make, choices that are consonant with good social behavior. Or, conversely, motivate the inmate to be a better criminal.
2) Our sentences are disproportionate to the offense(s) committed in that they are vastly longer than what is necessary to motivate a decision to rehabilitate. US sentences are some of the most vindictive in the world. 16 years for burglary: roughly what, 25% of the world's population were still in a crappy nappy 16 years ago? Contemporary society moves so fast that it takes an extraordinary person to catch up to anywhere near where the world has gone.
3) Most US prisons are *not* run by private contractors, they are run by the federal and state governments. Regardless of the operator, a prison is a business like any other. It has resources (prisoners), employees (guards / staff), infrastructure, etc. and a 'product' (a socially functional individual). Like any other business, it is motivated to continue to exist and to take actions to ensure that it does continue.
4) The entire premise of taking a person who does not know how to behave properly in society and isolating him with other people who also do not know how to behave well, for years at a time, and expecting all (or even a small minority) of them to learn to behave properly is ludicrous on its face. The concept of isolation (severe shunning) works fine if used in moderate doses and is supported by other measures. But 'time out' does not work in a vacuum; it must have other supportive actions around it. Nor does increasing the length of the shunning have a positive effect.
5) Prison is a brutal experience. On both the prisoner and the staff. Interactions between humans are two-way streets: You cannot brutalize another human being without yourself also being brutalized by your actions.
6) If the US truly believed in rehabilitation and the myth that a convicted person is restored to society made better we would see some actual support for felons leaving prison to help them reintegrate. Most long term US prisoners are released with whatever money they acquired in prison, a change of clothes, and a lift to the nearest town. (Think a moment... We have a guy who just finished 16 years for burglary. What resources does he have for shelter? For food? Entertainment? Progress toward a useful life? What is the most likely course of action for this person? Would you chose to starve or do without?)
DISCLAIMER: I AM an expert here. :) After 9 years in prison I managed to be that guy that got out and did okay. I did this *despite* the conditions in prison, not because of them. I am certain I succeeded only because I had enormous support to acquire a useful education after my release; because I was smart enough do that well (143 IQ --> high honors); and because I lied (by omission) about my time in prison whenever I sought employment. (I could not even get a job at McDonald's burning fries because I filled out their application truthfully!)