The scaling of crime concentration in cities
Though the growth of a city implies an increase in crime rates, the spatial concentration of offenses seems to be independent of the population size of the city. To test this, we employed Hoeffding’s independence test from which we could not reject the hypothesis that population size and the exponent of the power-law fit of the crime distribution are independent. In the case of thefts, the well-behaved α exponent suggests scale invariance, while robberies and burglaries seem to be more sensible to the cities, albeit uncorrelated with city size. In the double-y-axes plots, squares indicate the total number of offenses in a city during a year; while diamonds represent the average power-law exponent for a city.