Cost benefit analysis for crime science: making cost-benefit analysis useful through a portfolio of outcomes

Cost-benefit analysis is used increasingly in crime reduction and criminal justice evaluations yet remains a frustrating exercise that is easy to criticise and dismiss. Should the intangible costs of crime be included? Should local or national cost estimates be used? Are ‘saved’ police and criminal justice costs a benefit of prevented crime? Should anticipatory and diffused benefits plus displacement costs be included? Which benefit-cost ratios should be presented for which of a range of diverse audiences? How long does crime prevention last, and so how many years of benefit-returns should be assessed? In theory, such questions could lead to a frustratingly large, perhaps infinite, number of benefit-cost ratio outcomes. Yet most studies present a single benefit-cost ratio measure. This study proposes a limited portfolio of benefit-cost ratios to convey information to a range of audiences and promote transparency. The argument is illustrated by a case study of a burglary reduction scheme