By David Pérez Esparza and Shane D. Johnson and Paul Gill

  Whilst most countries have experienced a crime drop in the last few decades, Mexico experienced a dramatic increase in violent crime since the mid-2000s. In this paper, we test whether the increase in violence observed in Mexico is consistent with theories of crime opportunity. In particular, we explore whether the rise in violence between 1999 and 2011 can be explained by an increase in the availability of illegal weapons (a situational explanation) that resulted from policy changes (and increases in firearms production) in the bordering U.S. Analyses are conducted to test whether changes to U.S. gun policy led to an increase in the production of guns in the U.S., particularly in southern states bordering Mexico. And, if this in turn, led to an increase in the illegal availability of weapons in Mexico, and consequently to an increase in homicide. In addition to examining country-wide trends, we test the theoretical expectation that there was a pattern of distance-decay from the U.S.-Mexican border. Our findings suggest that changes to gun policy in the U.S. did increase the supply of firearms at the Mexican border, which increased opportunities for the trafficking into Mexico. Moreover, that there was a clear association between firearm availability and homicide rates. The analyses are thus consistent with the hypothesis that variation (across space and time) in illegal firearm availability in Mexico provides a parsimonious explanation for the observed variation in state-level homicide rates. These findings are observed after accounting for factors associated with traditional explanations of violence.

London: University College London,  Department of Security and Crime Science , 2019.   55p.