I think the root of the matter is this:

Will a convicted criminal use his newfound knowledge to pull himself up by the bootstraps and engage in contributing to society afterwards?

Or will he dedicate his time to learn how to become a better criminal?

Because when it comes right down to it. People who waste their time in jail, spending all day being Bubba's new girlfriend, and playing poker for smokes, will most definitely have a 95% recidivism rate.

I honestly believe that our only option is to educate society. Some of guys in prison are there because they lack the mental capacity to move forward with their lives beyond 15 year old thuggery. I also, don't see any problem with charging them tuition for the education they receive.