Comment: we have a large prison population because

(See in situ)

In reply to comment: But crime didnt go down in the 90's (see in situ)

we have a large prison population because

there is a lot of $$ in it and because if you don't lock up all the non-violent criminals then we would need jobs for all of them and the unemployment rate would skyrocket.

Crime DID go down in the 90's. It's a fact.

And it wasn't just because cops were doing a good job at locking people up.