A Difference-In-Differences Study of the Effects of a New Abandoned Building Remediation Strategy on Safety

Abstract

Vacant and abandoned buildings pose significant challenges to the health and safety of communities. In 2011 the City of Philadelphia began enforcing a Doors and Windows Ordinance that required property owners of abandoned buildings to install working doors and windows in all structural openings or face significant fines. We tested the effects of the new ordinance on the occurrence of crime surrounding abandoned buildings from January 2011 to April 2013 using a difference-in-differences approach. We used Poisson regression models to compare differences in pre- and post-treatment measures of crime for buildings that were remediated as a result of the ordinance (n = 676) or permitted for renovation (n = 241), and randomly-matched control buildings that were not remediated (n = 676) or permitted for renovation (n = 964), while also controlling for sociodemographic and other confounders measured around each building. Building remediations were significantly associated with citywide reductions in overall crimes, total assaults, gun assaults and nuisance crimes (p < 0.001). Building remediations were also significantly associated with reductions in violent gun crimes in one city section (p < 0.01). At the same time, some significant increases were seen in narcotics sales and possession and property crimes around remediated buildings (p < 0.001). Building renovation permits were significantly associated with reductions in all crime classifications across multiple city sections (p < 0.001). We found no significant spatial displacement effects. Doors and windows remediation offers a relatively low-cost method of reducing certain crimes in and around abandoned buildings. Cities with an abundance of decaying and abandoned housing stock might consider some form of this structural change to their built environments as one strategy to enhance public safety.

Conflict of interest statement

Competing Interests: The authors have declared that no competing interests exist.

Figures

Fig 1. Before and After Photos of Renovated Vacant Properties.

This figure shows four properties that received doors-and-windows remediation. Pink posters on doors of properties shown in the upper left- and lower right-hand quadrants notify the owner of a date by which the structure must be in compliance or face penalty.

Fig 2. Monthly Frequencies of Violation Citations (A), Violation Compliances (B) and Renovation Permits (C) between January 2011 and May 2013.

Fig 3. Map of Doors and Windows Ordinance violations, and treatment and control locations for violation compliance and renovation permits in Philadelphia, PA.

Data source: Philadelphia Department of Licensing and Inspection (2013) North (N), Northwest (NW), South (S) and West (W) sections are indicated.