Can increasing preventive patrol in large geographic areas reduce crime? A systematic review and meta‐analysis

Research summary We conducted a systematic review and meta‐analysis examining whether increasing preventive patrol in large areas reduces crime. Our review included experimental and quasi‐experimental studies that focused on areas such as beats, precincts, or entire jurisdictions and that measured a crime outcome either through official data or surveys. We identified 17 studies to include in our review. We used two methods for assessing study impacts: an approach which identified a primary/general outcome measure and a second approach which used robust variance estimation (RVE) and included all effect sizes across each study. Both approaches showed small crime prevention benefits (RVE: 9% decline; primary/general: 6% decline), but only the RVE model was significant at conventional levels (p