According to the International Labor Organization, in 2000-2011 wages in American prisons ranged between $\$0.23$ and $\$1.15$ an hour. In California, prisoners earn between $\$0.30$ and $\$0.95$ an hour before deductions.
Q. What is the total number of prisoners who worked during 2016?
Q. What was the total amount payed to the prisoners?
Q. What was the total contribution to the USA GDP by penal labour?
Q. What is the total value per prisoner to US prisons?