But the purpose of the prison system isn't to improve society and economics.
Improving society in a way that helps anyone who hasn’t earned it is contrary to the goals way too many voters.
Kant:
> [Punishment] can never be inflicted merely as a means to promote some other good for the criminal himself or for civil society. It must always be inflicted upon him only because he has committed a crime. For a human being can never be treated merely as a means to the purposes of another or be put among the objects of rights to things
The basic point is simple. If a person commits a crime, they should be punished in proportion to the crime. Full stop. Within that simple framework, efficiency is fine, but it shouldn't be the goal.
Easy mistake to make, I know.
Make take a reflecting break.