What is the population at risk?
The typical approach to calculating crime rates is to look at the distribution of incidents per residential population in a given area. While this approach works well at a city, provincial or national level, difficulty arises when the spatial areas of interest are small, for example neighbourhoods, with correspondingly small residential populations. The distribution of criminal incidents across urban areas is often concentrated in or near the city centre, where residential populations are relatively low, but where there are otherwise high concentrations of people either working or spending time in other ways. Rates based on residential population alone will artificially inflate the crime rates in these urban core neighbourhoods since the total population at risk in these areas has not been taken into account (see for example, Oberwittler and Wiesenhütter 2002). While information about the true population at risk does not currently exist in any precise form, alternative approaches to ca
