Location quotients, ambient populations, and the spatial analysis of crime in Vancouver, Canada Paper by Anderson, M.K Environment and Planning. 39: Yong Min Ho, Geography, GEOG th February 2008

Role of location quotient and ambient population in crime analysis Problem / background: Crime count and crime rate are potentially useful measure of criminal activity in identifying ‘hot spots’ of crime, but it does not do much for understanding why crime is so prevalent in those areas. Little research on alternative crime rate calculations has been done. Research objective: How is location quotient related to the specialization of criminal activity, and what are the possible explanations for it?

Definitions Location quotient measures the percentage of a particular type of crime in a region of Vancouver relative to the percentage of that same crime in all of Vancouver. Ambient population measures how many people are expected to be in a given square kilometer at any time.

Location quotient vs Crime rate Certain regions within the city may have a low rate of a certain crime (e.g. Automobile theft), but have a disproportionate share of that crime when compared to the whole city, vice versa.

Methods, data & test: Overlaying Location Quotient and Ambient Population with socioeconomic/demographic data 1. Crime activity data are geocoded as point locations, after which location quotients are calculated and made into a choropleth map. 2. The socioeconomic and sociodemographic variables used to represent area characteristics come from Statistics Canada’s 1996 Census data. 3. Crime rate, location quotients and their relationship with socioeconomic/demographic variables observed. 4. These are then further tested using ambient population, social disorganization and routine activity theory as a theoretical framework.

Results The spatial pattern of the location quotient for automobile theft has little resemblance to the automobile crime rate. Areas with high location quotient are largely represented in downtown areas. The results for break and enter are quite different, with the spatial pattern of the break and enter location quotient being almost the opposite of the automobile theft location quotient. High location quotients are found outside of the downtown area.

Conclusions Their conclusion Areas with high degrees of population change have increased levels of automobile theft specialization, most probably due to a lack of guardianship. Increases in average income also increases this specialization, most likely places with high valued vehicles to steal. Increases in percentage of university graduates and average income decrease the specialization of places for breaking and entering. Unemployment rate has the largest magnitude impact on the location quotient for breaking and entering, due to the non-availability of vacant rooms.

My evaluation of the research I feel that this research has attempted to give a broader and clearer picture of the spatial distribution of crime by using location quotient to seek areas of crime specialization, which differs from simply using crime rates to mark out hot spots. Most arguments and inferences were coherent, largely due to the fact that many variables were used, such as ambient population, to provide more convincing inferences by considering time-space variables. These all add up to give a well-rounded argument and conclusion, which I feel should be considered in our future researches.