The expansion of the U.S. criminal justice system is often justified in the name of public safety. While incarceration does have crime-reducing capabilities, it also has numerous negative effects, such as decreased likelihood of employment and other “collateral consequences” for those incarcerated. Thus, it’s hard to say whether incarceration does more good than harm. This is a tricky question to answer, as the outcomes of incarceration are often hard to compare. However, Michael Light and Joey Marshall use a bevy of administrative panel data to compare whether incarceration saves more lives through reducing homicides than it costs lives through increases in infant mortality.

Overall, they find that the incarceration rate both decreases the homicide rate and also increases the infant mortality rate. The authors estimate that the “net benefit” of incarceration is much smaller when the mortality costs are taken into account. In other words, there seems to be a very weak or even non-existent return on incarceration when considering mortality. Thus, while it appears that incarceration does indeed “save lives,” incarceration also causes deaths, muddying the picture of the benefits of imprisonment. This research challenges claims that increased imprisonment will greatly enhance public safety and human well-being, and gives a glimpse into the varying effects the criminal justice system can have.The incarceration rate both decreases the homicide rate and also increases the infant mortality rate.