Forty years ago, Pennsylvania had 7 prisons.  Today we have 25. Incarceration has increased by 500% while the crime rate has gone down. The impact of mass incarceration on safety in Pennsylvania has been modest, at best.  Crime rates have gone up and down. They are largely independent of the number of people in prison. Violent crime rates in Pennsylvania are now same as in the mid-1970s, before mass incarceration began.