The United States has the highest reported incarceration rate in the world, and the debate has raged for decades: does prison reform the bad guys, or simply make them better at committing crimes?
Theories abound, but it's worth considering one study that argues spending time in prison actually helps a person increase their earnings power from criminal activity.
A criminal who continues to engage in illegal activity after serving time will make roughly $6,300 more a year than a person who's served no time in prison, according Ohio University Sociologist Donald Hutcherson.
"I wanted to see if spending time in prison actually led towards failure in the conventional labor market; and once you fail there, does it lead to success in the underground economy," he said. "And I found that's the case."
The author of "Street Dreams: The Effect of Incarceration on Illegal Earnings," Hutcherson based his findings on analyzing eight years of data from the National Longitudinal Survey of Youth.
Hear the "American Greed" story of a repeat offender who graduated from state prison to two stints in federal pens for running multiple multi-million-dollar schemes.
Some argue that prisons act as a"finishing school" for criminals, but Hutcherson does not completely agree. He argues that while prison can boost a person's knowledge of illicit activity, having a prison record is a major factor behind what forces them to make money through crime once they're released.
"You can make the argument that guys are struggling when they get out of prison because they lack skills and [they] have a prison record," he said.
As the overwhelming amount of research shows, it is very difficult for the ex-incarcerated to get a normal job once they return to the "real world." Rates of recidivism — the pattern of ex-cons falling back into crime after leaving jail — exceed 60 percent, according to Department of Justice data.
"Most able-bodied men will not sit around doing nothing when they fail in conventional labor market," Ohio University's Hutcherson said. "They're going to go out and make money somehow; and they do so in the illegal underground economy."
(Read More: "From Pimping and Street Crime to White Collar Scheming")