Again we come to the key word APPROACH, with the present approach being the negative of sending people to jail or prison as a form of PUNISHMENT.
With Imp and the positive approach would be to send people to jail and prison with the thought of being given a real and genuine opportunity to become a productive member of SOCIETY. After all it just may have been the case of a lack of money, and even the lack of opportunity that led to them committing the crime in the first place. You already have them in some what of a controlled environment. Why not help them to develop their minds to the benefit of the whole.