The number of people held in U.S. jails has increased from 157,000 in 1970 to 690,000 in 2014, spurring the costly construction or expansion of new or existing jails, especially in small and midsize counties, a report from the Vera Institute of Justice finds. According to the report, In Our Own Backyard: Confronting Growth and Disparities in American Jails (20 pages, PDF), the jail incarceration rate for African Americans averaged 841 per 100,000 county residents and was 50 percent higher in small counties, while the female jail population soared to 109,000 in 2014 from 7,739 in 1970, with many of the highest incarceration rates in small and midsize counties. The report attributes the increases to policy choices embedded in state and federal criminal laws that affect jail admissions and length of stay without reducing crime, and concludes that sustainable jail reform requires jurisdictions to not only understand their own jail's history but also to track whether intended outcomes are being achieved. To that end, the authors highlight the Vera Institute's Incarceration Trends, an interactive tool that help counties examine how their use of incarceration has changed over time, how that use compares with similar counties, and how to plan for and evaluate reform efforts.