Objective

Place-based blight remediation programs have gained popularity in recent years as a crime reduction approach. This study estimated the impact of a citywide vacant lot greening program in Philadelphia on changes in crime over multiple years, and whether the effects were moderated by nearby land uses.

Methods

The vacant lot greening program was assessed using quasi-experimental and experimental designs. Entropy distance weighting was used in the quasi-experimental analysis to match control lots to be comparable to greened lots on pre-existing crime trends. Fixed-effects difference-in-differences models were used to estimate the impact of the vacant lot greening program in quasi-experimental and experimental analyses.

Results

Vacant lot greening was estimated to reduce total crime and multiple subcategories in both the quasi-experimental and experimental evaluations. Remediating vacant lots had a smaller effect on reducing crime when they were located nearby train stations and alcohol outlets. The crime reductions from vacant lot remediations were larger when they were located near areas of active businesses. There is some suggestive evidence that the effects of vacant lot greening are larger when located in neighborhoods with higher pre-intervention levels of social cohesion.

Conclusions

The findings suggest that vacant lot greening provides a sustainable approach to reducing crime in disadvantaged neighborhoods, and the effects may vary by different surrounding land uses. To better understand the mechanisms through which place-based blight remediation interventions reduce crime, future research should measure human activities and neighborly socialization in and around places before and after remediation efforts are implemented.

中文翻译：

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通过修复空地减少犯罪：附近土地利用的调节作用

 客观的

近年来，基于地点的枯萎病补救计划作为一种减少犯罪的方法越来越受欢迎。这项研究估计了费城全市范围内的空地绿化计划对多年来犯罪变化的影响，以及附近土地利用是否会缓和这种影响。

 方法

空地绿化计划采用准实验和实验设计进行评估。准实验分析中使用了熵距离加权，以将控制地块与预先存在的犯罪趋势上的绿色地块进行匹配。固定效应双重差分模型用于估计空地绿化计划在准实验和实验分析中的影响。

 结果

在准实验和实验评估中，空地绿化估计可以减少总犯罪和多个子类别。当空地位于火车站和酒馆附近时，修复空地对减少犯罪的效果较小。当空地整治位于商业活跃区域附近时，犯罪率减少幅度更大。有一些暗示性证据表明，当位于干预前社会凝聚力水平较高的社区时，空地绿化的效果更大。

 结论

研究结果表明，空地绿化为减少弱势社区的犯罪提供了一种可持续的方法，其效果可能因周围土地用途的不同而有所不同。为了更好地了解基于地方的枯萎病修复干预措施减少犯罪的机制，未来的研究应该在实施修复工作之前和之后测量地方及其周围的人类活动和邻里社会化。