https://www.scientificamerican.com/article/do-prisons-make-us-safer/

One person is sentenced to state or federal prison every 90 seconds in the United States, amounting to almost 420,000 per year.   The U.S. has the highest incarceration rate in the world. We incarcerate for multiple reasons, including justice and punishment, but one of the main justifications is public safety. Putting individuals convicted of crimes, especially violent crimes, in prison is thought to make the rest of us safer.

But how much safety does all this imprisonment actually buy us? A study I recently published with colleagues shows the answer is very little, especially in the long-term.