The Police Response Effort Index: A New Method for Measuring Demand

The Police Response Effort Index (PREI) is a method for measuring demand for police service that involves weighting demand incidents by the average time it takes police to resolve them. A police organization can calculate its own PREI weight values using Computer Aided Dispatch data on the time police spend on scene during their initial response. Police can use a PREI to target resources to high effort people and places, test whether initiatives reduce effort, and track changes in demand that traditional counts may mask.