Research summaryWe 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 < 0.05). There was no significant evidence of displacement. Moderator analyses suggest that as dosage increases so do the crime prevention impacts. In RVE models, preventive patrol was associated with significant reductions in property and violent crime, but nonsignificant increases in drug and disorder offenses.Policy implicationsIncreasing preventive patrol activities has the potential to reduce crime in large administrative areas. At the same time, existing studies offer little guidance as to how such preventive patrol should be carried out. Deterrence theory, as well as evidence from studies of hot spots policing, suggests that the greatest benefits will be gained from informing patrol efforts about where and when crime occurs. Although more research is needed regarding patrol allocations in large areas, present knowledge suggests that the more such patrols can be targeted at specific places at specific times, the greater will be the crime control benefits. In this context, we argue that police agencies may want to apply a hybrid approach to police patrol, which would include a combination of hot spots policing units and general patrol units informed by data on where crime is concentrated.

中文翻译：

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在大片地理区域增加预防性巡逻可以减少犯罪吗？：系统回顾和荟萃分析

研究总结我们进行了系统回顾和荟萃分析，探讨在大面积地区增加预防性巡逻是否可以减少犯罪。我们的审查包括实验性和准实验性研究，这些研究重点关注街区、辖区或整个司法管辖区等领域，并通过官方数据或调查来衡量犯罪结果。我们确定了 17 项研究纳入我们的审查。我们使用两种方法来评估研究影响：一种方法确定主要/一般结果指标，另一种方法使用稳健方差估计 (RVE) 并包括每项研究的所有效应大小。两种方法都显示出较小的预防犯罪效益（RVE：下降 9%；主要/一般：下降 6%），但只有 RVE 模型在传统水平上显着（p< 0.05）。没有明显的位移证据。主持人分析表明，随着剂量的增加，预防犯罪的影响也会增加。在 RVE 模型中，预防性巡逻与财产和暴力犯罪的显着减少有关，但与毒品和骚乱犯罪的增加无关。政策影响 增加预防性巡逻活动有可能减少大行政区域的犯罪。与此同时，现有的研究对于如何进行这种预防性巡逻几乎没有提供指导。威慑理论以及热点警务研究的证据表明，告知巡逻人员犯罪发生的地点和时间将获得最大的好处。尽管需要对大区域的巡逻分配进行更多研究，但目前的知识表明，在特定时间针对特定地点进行的巡逻越多，控制犯罪的好处就越大。在这种情况下，我们认为警察机构可能希望对警察巡逻采用混合方法，其中包括热点警务单位和根据犯罪集中地点数据提供信息的一般巡逻单位的组合。