The effectiveness of burglary security devices

This study measures the effectiveness of anti-burglary security devices, both individually and in combination. Data for 2008–2012 from the Crime Survey of England and Wales are analysed via the Security Impact Assessment Tool to estimate Security Protection Factors (SPFs). SPFs indicate the level of security conferred relative to the absence of security devices. It finds that, for individual devices, external lights and door double locks or deadlocks, are most effective but, counter-intuitively, burglar alarms and dummy alarms confer less protection than no security. Combinations of devices generate positive interaction effects that increase protection more than additively. In particular, combinations with door and window locks plus external lights or security chains confer at least 20 times greater protection against burglary with entry than no security. Although further research is needed, the findings are consistent with improved security playing an important role in long-term declines in burglary rates.