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Vacant lot to community garden conversion and crime in Milwaukee: a difference-in-differences analysis
  1. David R Beam1,
  2. Aniko Szabo2,
  3. Jared Olson1,
  4. Lawrence Hoffman3,
  5. Kirsten M M Beyer1
  1. 1Division of Epidemiology, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
  2. 2Division of Biostatistics, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
  3. 3Groundwork Milwaukee, Milwaukee, Wisconsin, USA
  1. Correspondence to Dr David R Beam, Division of Epidemiology, Institute for Health and Equity, Medical College of Wisconsin, Milwaukee, WI 53226, USA; dbeam2{at}


Background Vacant lots generate the perception of neglect and are often opportunistic locations for crime. Evidence is building to suggest that greening vacant lots, especially through community engaged approaches, is associated with reductions in some types of crime.

Methods Using a retrospective quasi-experimental approach, we compared the conversion of vacant lots into community gardens (n=53) with a group of matched control lots (n=159) to examine the effect of this intervention on police reported theft, violent and nuisance crime in Milwaukee, Wisconsin. Conversions often involved the addition of planter boxes to create a garden, and sometimes included benches, paths, works of art or other landscaping features. Public crime data were used to generate crime rates within 100 m and 250 m around each lot.

Results Violent and nuisance crime rates are lower near treatment lots based on an unadjusted difference-in-differences analysis of means and two Poisson regression models. While no substantial effects were observed among theft crimes, the most consistent crime rate reductions were found among violent crime within 250 m, ranging between 3.7% and 6.4% across analyses.

Conclusions Despite the small number of interventions, community-driven vacant lot to garden conversions were associated with slight reductions in crime. Urban greening initiatives may be a promising strategy to reduce urban crime and warrant further study.

  • geographical / spatial analysis
  • environmental modification
  • violence
  • community

Statistics from


  • Contributors DRB led the project, including conceptualisation, data analysis and writing of the manuscript. KMMB guided the process of study design based on the available data, recommendations regarding data analysis methods, and provided input with revisions of the manuscript. LH was responsible for the acquisition of garden records and provided additional assistance with interpretation of collected garden data as well as insight into how various garden spaces are used. JO provided assistance with obtaining background information for the work, ensured the appropriate characterization of garden and vacant lots and provided input with writing of the manuscript. AS was primarily involved with the determination of appropriate data analysis methods based on available data and guided the team’s interpretation of the results based on limitations of the data and analyses applied. All authors were in agreement with the publishing of the article.

  • Funding This study was partially funded through the Advancing a Healthier Wisconsin Endowment.

  • Map disclaimer The depiction of boundaries on this map does not imply the expression of any opinion whatsoever on the part of BMJ (or any member of its group) concerning the legal status of any country, territory, jurisdiction or area or of its authorities. This map is provided without any warranty of any kind, either express or implied.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting, or dissemination plans of this research.

  • Patient consent for publication Not required.

  • Ethics approval This study was approved by the Institutional Review Board at the Medical College of Wisconsin.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available on reasonable request. Datasets generated and analysed during the study may be available from the corresponding author, DRB, on reasonable request and with permission granted by Groundwork Milwaukee.

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