An old study that said that longer sentences would lead to more crime. I'm not really qualified to comment on the validity of the study. These kind of studies almost always have some kind of hole or another. I'm just going to use it as a springboard to make the observation that the idea of prison as being some kind of reformative experience seems to have almost vanished. In our society today the emphasis seems to have shifted to prison as punishment.
Prisoners are getting out of prison less and less equipped to deal with the realities they face in the communities they are released to. The main advantage of keeping people in prison longer is that if they get out when they are old they may be too tired to commit any violent crimes. This seems to be kind of a waste to me.
People with tinfoil hats talk about the prison industrial complex, but it seems to me that there may be a grain of truth in the idea that our current system of justice has an unseemly element of profit motive to it.
Not that I really have any idea what to do about it.