The volunteer programme ‘Night Ravens’: a difference-in-difference analysis of the effects on crime rates

The volunteer programme ‘Night Ravens’ (NR) was founded in Sweden in 1987 and has, over the years, developed into a Scandinavian concept covering large areas of Sweden, Denmark, Norway, Greenland and the Faroe Islands. The NR programme is a crime prevention initiative with adults walking the streets at night in identifiable ‘uniforms’ in areas with high activity. The purpose of this study is to evaluate the effects of the NR programme in Denmark based on a volunteer set-up with a less intrusive approach to situational crime prevention than, for instance, hot spot policing. The analyses are based on a longitudinal data set containing socio-demographic information on all 585 postcode districts in Denmark and quarterly records of six different categories of reported crimes in the years 2001–2010.We apply a difference-in-difference design and compare development in crime rates in districts with NR organizations to districts without NR organizations. The results show no difference in the crime rates between Danish postcode districts with and without the NR programme. Hence, we cannot identify positive effects of situational crime prevention when evaluating this Scandinavian volunteer programme with a more informal guardianship.