Nudge Failures and Crime Indexes: Inside March–July 2018

Abstract

Research question. To what extent does citizen-reported crime in 500-metre square areas in Denmark, and arrests of individuals legally excluded from those areas for intimidating behavior, decline in the 3-month time periods in which their Exclusion Zone Orders (EZOs) are in effect, compared to the most recent 3-month period prior to the EZO?

Data Individual-level data on 2,441 arrests of the 161 offenders who were the subject of all 218 EZOs granted in Denmark from 2009 through 2016 were collected from the Danish Na-tional Police Database, as well as place-based reported crime data for the location of each of the busiest 7 (out of 41) of the Exclusion Zones (EZs) and matched control areas.

Methods The two units of analysis are individuals targeted by the EZOs and location of the EZs. A descriptive time series analysis compared offending before and individuals received EZOs. Standardized mean differences were calculated between seven locations which re-ceived a high rate of EZOs and their matched control sites, all distinguishing police-reported crimes from those reported by victims or witnesses.

Findings Using a difference-in-difference analysis in comparisons to the respective matched control areas, a moderate decrease in the number of citizen-reported offences was observed in six out of seven targeted zones when the EZOs were in effect. There was no indication of a displacement effect to offences outside the EZ.

Conclusions. The positive results of this tracking study suggest that more rigorous testing the use of EZOs across Denmark could demonstrate that EZOs can cause reductions in crime and harm.