Objectives

To examine how the practice of daily proactivity affects and responds to changes in crime at micro geographic and temporal scales.

Methods

Police calls for service and automated vehicle location data from a large suburban jurisdiction were used to create comprehensive measures of police proactivity. Panel data and the generalized method of moments framework were applied to tease out the endogenous relationships between crime and police proactivity and understand the unique impact of proactive patrol and crime upon one another.

Results

Daily police proactivity in this locality was highly stable at micro places, although police did intensify their activities very briefly in response to recent changes in crime. In turn, increases in proactive patrol generated immediate increases in crime reporting, followed by fleeting residual deterrent effects that were weaker and less robust. The patterns remained relatively consistent when varying the units of analysis or focusing on hot spots with different profiles of proactivity, but the deterrent effects appeared more sensitive to model specification. Of all measures of proactivity, patrols of medium length and non-traffic enforcement activities were associated with stronger evidence of crime reduction effects.

Conclusions

Short-term adjustments in hot spot patrols appear to produce both reporting effects and temporary residual deterrent effects as measured through calls for service and police vehicle location data. Police could potentially enhance and prolong their deterrence by adopting more deliberate strategies with their daily proactive behaviors, including making their proactive activities more targeted and sustained.

中文翻译：

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衡量日常警察积极活动的影响：解决内生性问题

目标

在微观地理和时间尺度上研究日常主动行为如何影响和应对犯罪变化。

方法

来自大郊区的警察要求服务和自动车辆位置数据被用于制定全面的警察主动性措施。运用面板数据和通用的矩量法框架来梳理犯罪与警察主动性之间的内在关系，并了解主动巡逻与犯罪之间的独特影响。

结果

尽管在最近的犯罪变化中，警察确实非常短暂地加强了活动，但在微小的地方，该地区警察的日常活动非常稳定。反过来，主动巡逻的增加使犯罪报告立即增加，随后短暂的威慑力减弱而减弱。当改变分析单位或关注具有不同活动特征的热点时，模式保持相对一致，但是威慑作用似乎对模型规格更为敏感。在所有主动措施中，中等长度的巡逻和非交通执法活动与减少犯罪效果的更有力证据有关。

结论

热点巡逻的短期调整似乎同时产生了报告效应和暂时的剩余威慑效应，这是通过呼唤服务和警车位置数据来衡量的。警察可以通过采取更加谨慎的策略来应对日常的积极行为，从而增强和延长威慑力，包括使主动性活动更具针对性和持续性。