Association for Public Policy Analysis & Management

Chicago experienced an unprecedented increase in gun violence in 2016. Homicides that year rose by almost 60 percent, the increase alone approaching the total number of homicide victims in New York City. In response, the Chicago Police Department (CPD) and the City implemented a new policing strategy that gives local commanders more complete information on crime in their districts. In addition to streamlining data access, this district-wide intervention, the Strategic Decision Support Center (SDSC), functions as a management tool to help commanders deploy and monitor their resources more effectively. The University of Chicago Crime Lab worked closely with CPD to implement SDSCs in the six districts that experienced the highest rates of gun violence in 2016. Crime Lab staff developed tools to summarize data, conducted trainings on the use of new technology, and worked alongside officers in the role of civilian crime analysts in the SDSCs. The homicide rate declined by 15 percent in 2017 relative to 2016, with some of the largest decreases occurring in SDSC districts. However, determining the SDSCs' role in those reductions is made difficult by the fact that the SDSC districts, which experienced some of the largest violence increases in 2016, lack a comparison group. To address this, we construct a comparison district for each SDSC district using synthetic controls methods, which we extend through the introduction of a geographic subsampling technique that improves the precision of our estimates. We find that the implementation of the SDSCs, particularly in the Englewood neighborhood of Chicago, resulted in substantial reductions in gun violence.