Are they contributing to GDP as much as they would if free? I really doubt it. I think most of this is busy-work, or work the prison system can sell easily to a

Are they contributing to GDP as much as they would if free? I really doubt it. I think most of this is busy-work, or work the prison system can sell easily to a private company for extra profit. But I'm sure (having done no research and having no supporting data, so I know it's true) that productivity inside can't be more than a tiny fraction of what it would be on the outside.