By Rebecca Tublitz

After four decades of explosive growth in the number of people arrested, jailed, and imprisoned in the United States, a growing consensus about the overreach of mass incarceration and unjust systems of punishment has emerged in the 21st century. Seeking to raise national attention to the problem of overuse and misuse of incarceration in local jail systems and to catalyze innovation and reform at the local level, in 2015, the John D. and Catherine T. MacArthur Foundation (MacArthur Foundation) launched the Safety and Justice Challenge (SJC). In its eighth year, the SJC now supports a diverse network of more than 57 cities, counties, and states across the country in developing and implementing decarceration strategies and represents an ambitious effort to generate transformative change in how localities conceive of and use jail incarceration.

Data, measurement, and evaluation has been pivotal in guiding this initiative—for identifying drivers of the jail population, designing innovative decarceration strategies, monitoring progress, and evaluating and understanding performance. CUNY ISLG plays a leading role in these data collection and analysis activities across the SJC, serving as a central liaison between local jurisdictions, external researchers, technical assistance providers, and the MacArthur Foundation.

This report focuses on the role that local data has played in the SJC initiative and CUNY ISLG’s work to develop and support the SJC model of data-driven reform. The report details:

• The collection of data and how data were used by many stakeholders across the initiative;

• The build-out of CUNY ISLG’s data repository;

The development and use of standardized performance measures for reporting site progress towards reducing

• Jail populations and eliminating racial and ethnic disparities; and

• Lessons learned from working with cross-agency administrative data to drive reform and evaluate policy change.

New York: CUNY Institute for State & Local Governance —————— Safety and Justice Challenge. 2024. 36p.