I can tell you this on a stack of Bibles: prisons are archaic, brutal, unregenerative, overcrowded hell holes where the inmates are treated like animals with absolutely not one humane thought given to what they are going to do once they are released. You're an animal in a cage and you're treated like one.
The uneven impact of actual enforcement measures tends to mirror and reinforce more general patterns of discrimination (along socioeconomic, racial and ethnic, sexual, and perhaps generational lines) within the society. As a consequence, such enforcement (ineffective as it may be in producing conformity) almost certainly reinforces feelings of alienation already prevalent within major segments of the population.
The degree of civilization in a society can be judged by entering its prisons.
Crimes lead one into another; they who are capable of being forgers are capable of being incendiaries.