Applying Time-series Cross Correlation Analysis to Examine the Nexus between Firearms and Homicide in Hong Kong

Abstract

This paper applied time series analysis to examine the nexus between firearm robberies and homicide in Hong Kong Special Administrative Region (HK). Recent years have seen a reduction in firearm related offences in HK compared to Britain. For instance, only three cases of firearm robbery in 2004 in HK (0.1% of all robbery; 2,237 incidents) involved genuine firearms, compared to 4,117 firearm robbery incidents (4% of all robbery) in Britain in the same year. This paper established a cross-correlation coefficient of 0.50 at lag 0 for the annual rate of two serious crimes, genuine firearm robbery and homicide, after identifying an ARMA(1,0) model from each time series (1972–2002). The results suggest that the prevalence of firearm robbery is moderately associated with the prevalence of homicide in HK.