Various states have or recently had chain gangs, in which groups of prisoners perform physical or menial work in public while wearing chains/shackles. Supporters claim that it acts as a deterrent - either to the individual workers as a deterrent to recidivism, or to members of the community who see the chain gang at work.
For example, in Alabama in 1995:
The state's Prison Commissioner, Ron Jones, who believes prison should be hard, said there were a lot of reasons why he decided to revive chain gangs, but the big one was "deterrence." He said the sight of a man in chains would leave a lasting impression on young people.
In Illinois in 1996:
This year, 20,000 inmates will be released from Illinois prisons; however, within three years, 9,000 of those released will again commit serious crimes and be sent back to the state penitentiary. These numbers signify that our current system is not working and that prisoners have no fear of going to prison or going back to prison. This is where we believe chain gangs can serve a useful purpose as a deterrent to crime.
In Arizona in 2003:
Arpaio, who was elected sheriff in 1992 promising to be tough on crime and intends to seek a fourth term next year, said he wanted to start a chain gang for juveniles soon too.
"I use it for deterrence to fight crime. I put them right on the street where everyone can see them. If a kid asks his mother, she can tell them this is what happens to people who break the law," he said.
In Florida in 2013:
"I remember growing up as a small kid, looking out the window of our home at members of the chain gang working in a ditch and thinking to myself: That's not a place I would ever want to be," Ivey said. "I've said from the very beginning that I'm going to put emphasis on crime prevention, and this is a component of that. Not wanting to go to jail is a form of crime prevention."
Is there any recent empirical evidence one way or the other on whether chain gangs are effective at deterring crime?