If there's a single way to spur the economy it would be to close down many of these prisons, and reprogram the law enforcement goal of populating them.
The government of the US does not even remotely work for her people. They serve themselves.
Edit: This is a slightly complex relationship but it holds. Once you start down a path of mass incarceration, there's pressure to find a profitable use for prisoners. Once you have a profit-making use, there's a demand for more prisoners. So while it is chicken and egg, it's pretty clear that the demand is a factor today. It is also worth noting that the the 13th Amendment specifically allows slavery as punishment for a crime.