That's true, but 8% of anything in the US is a lot. There's roughly 2.2 million prisoners so maybe 200k of them are held in private prisons. And as someone points out upthread, when you add in all that prison-building, the firms that deliver services tot he corrections market and so on, it adds up to a lot of economic activity.
About 133,000 as of 2013. And two companies (CCA and GEO Group), both of whom are aggressively fighting for tougher laws as a matter of course have about 129,000 bed capacity.
