Comparing Measures of the Concentration of Crime at Places and Times

Since place-based crime has been studied, scholars have employed a variety of ways to describe the concentration of crime at places. Most usefully, they sometimes provide a full distribution of crime across street segments, or among addresses, or other small geographic areas of interest. This is feasible if the researcher is showing the distribution of crime at places throughout one or two larger areas, such as a city. In such circumstances, a few tables or graphs will be sufficient. But once researchers started looking at spatial areas numbering in the hundreds and thousands, like street segments, then describing the internal distribution of crime within each becomes cumbersome. We need summary measures of crime concentration. The mean, median, and mode are not appropriate for this task: the first two because of the highly skewed nature of crime distributions, and while the mode is better, it does not provide enough information