Last week, the Supreme Court ordered California to release at least 30,000 prisoners due to poor prison conditions caused by overcrowding.
This is what economists call a “natural experiment,” or what I prefer to call an “accidental experiment.” The Supreme Court order will be a “shock” to the California prison system, leading to roughly a 10 percent reduction in the prison population there. I used this sort of accidental experiment in a paper I published back in 1996, finding a large impact of mandated prison releases on state crime rates. If my estimates remain relevant to the current time period, I predict that California violent crime rates should rise about 4 percent relative to the rest of the U.S. over the next few years. That adds up to about 80 extra homicides a year.
Five years from now, no doubt, an economics graduate student will analyze the data and tell us what the actual numbers look like. Unless, of course, I beat them to the punch!