Is crime worse in larger cities? Many people think it is, but what do the data say? Of course there are many types of crime, with some worse than others. A large city might have more traffic offences and fewer assault cases. We need a way of combining all types of crime, weighted according to how severe the crime is. That’s what Statistics Canada’s “Crime Severity Index” does. Each type of offence is assigned a weight derived from actual sentences handed down by courts. More serious crimes are assigned higher weights, less serious offences lower weights. As a result, the index ref lects the overall severity of crime in a given city. For a full explanation of the index and how it’s calculated, refer to the 2008 report “Measuring Crime in Canada: Introducing the Crime Severity Index and Improvements to the Uniform Crime Reporting Survey” (Statistics Canada, Catalogue No. 85-004-X).

The data file ch06_MCSP_Crime_in_Canada contains the crime severity index and the population of certain Canadian cities. Draw scatterplots and calculate the correlation coefficients for the whole of Canada and then separately for each region of Canada. (Ottawa-Gatineau should be included in both the Ontario and the Quebec regions.) Comment on whether you think your correlation coefficients are representative of those regions, giving reasons for any doubts you may have. Finally, tackle the question: Is crime worse in larger cities?