Vera researchers found that contrary to the national narrative, the incarceration rate at large county jails are now lower than most other counties, thanks to concerted efforts by cities like New York and Los Angeles to curb their ballooning jail populations. Meanwhile, rural jail populations have spiked in recent years, even though crime rates have remained largely the same.

Digging deeper into the data revealed a few reasons why. For starters, pre-trial detention rates—that is, the percentage of people who serve time while awaiting trial—have tripled nationwide since 1970. Still, as urban pre-trial detention rates have dropped precipitously, they’ve risen the most in the country’s rural counties with fewer than 250,000 residents. Between 1970 and 2013, rural pre-trial detention rates grew some 436 percent.