The association between urban trees and crime: Evidence from the spread of the emerald ash borer in Cincinnati

The ecological impact of invasive tree pests is increasing worldwide. However, invasive tree pests may also have significant social costs. We investigated the association between the emerald ash borer (EAB)—an invasive tree pest first discovered in the US in 2002—and crime in Cincinnati, Ohio. We used a natural experimental approach, and compared crime (in 11 classes) on census block groups infested with EAB with crime on block groups not infested with EAB between 2005 and 2014. We accounted for demographic and biological differences between infested and un-infested block groups using propensity-score weighting. EAB infestation was significantly and positively associated with relative increases in crime in all but four crime categories. Our results suggest that invasive tree pests may be associated with social costs worth considering when managing invasive species. By extension, healthy trees may provide significant social benefits.