We look in this section at the detail of how estimates are made.
Three principal types of cost are identified in a review of Basic Principles for Costing Crime For each cost type we summarise here the relevant principles for estimation and some of the practical issues in collecting and analysing cost data:see
The methodology outlined is based on a ‘bottom-up’ approach which identifies the various types of costs crimes may trigger and adds them up. The alternative is to use a ‘top down’ approach which identifies the costs crime as a whole imposes and tries to establish how much people would be prepared to pay to reduce it. For more discussion see this excerpt from the Bibliography: Top-down versus bottom-up approaches. In an ideal world it would be possible to present a model in which users are prompted for bits of information (e.g. what was the average loss of earnings for victims injured in assaults?) and have a ‘black box’ produce a completed table of cost estimates by offence type. But wide variation across countries in data availability makes this impossible. The user of the model therefore has to use common sense in compiling the best possible estimates from what is available.
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