Wow, those are big numbers. Having 25% of the world’s incarcerated people is a heavy toll on the budget and tells something about the criminal system itself.
It seems that USA has the highest imprisonment rate per 1000 people in the world and that the convicts, once they get out of the prisons, are not allowed to receive student well fare or get hired in some places. Some convicts turn to suicide, become homeless or turn back to crime.
Costs for each prisoner? $100k/year/prisoner. It seems that the total cost of prisons in USA is about $75 billions per year.
UPDATE: some cities consider using public humiliation instead of incarceration for certain crimes.