A Police Response Effort Index to complement counts and harm indices in understanding crime and policing demand

Abstract

Responding to crime and non-crime policing demand in the increasingly complex policing environment calls for increasingly nuanced means of measuring demand. Complementing traditional crime counts, the recent development of crime harm indices provides one such means, whereby crimes are weighted by estimates of their harm or severity. Analysis using crime harm indices has shown that high harm victims, offenders, locations and times differ from the people and places that unweighted crime counts would highlight as a priority for police resource. However, crime harm indices apply only to crime, so they cannot be used to analyse both crime and non-crime demand, and harm is but one way of differentiating demand types. We therefore present an additional, complementary tool: the Police Response Effort Index (PREI). The PREI provides values for weighting crime and non-crime demand types by the amount of effort (time) typically involved during police’s initial response. It enables police to make decisions and target interventions with a more nuanced understanding of when, where and on whom police effort concentrates. This paper describes the development of the New Zealand PREI, providing a potential template for other jurisdictions.