Spillover effects on homicides across mexican municipalities: A spatial regime model approach

abstract

© Southern Regional Science Association 2015. This paper investigates the existence of spatial regimes of high violence levels across Mexican municipalities. Our approach consists of providing a framework to explicitly address spatial heterogeneity, which might suggest instability in the structural determinants of homicides. In this context, a distinction is made in relation to the regimes in municipalities within states with long-standing trafficking activities by comparing those municipalities that have been exposed to joint operations (operativos conjuntos) and those that were not exposed to the operations. Spatial econometric models were estimated for each regime to investigate possible spillover effects arising from the covariates. The results point to differences in regard to the significance, magnitude, and sign of the effects related to some variables according to each spatial regime¿s specification. While the direct effects show that socioeconomic variables tend to play an important role in explaining the variation of homicides not in the joint operation regime, the historical level of homicides and closeness to the U.S. border operate in a more significant way for those municipalities in the joint operation regime. In regard to the estimates of indirect effects, a positive and significant spillover effect upon homicide rates is attributed to our law enforcement variable as well as to the proxy variable of informality. These spillover effects are found to be greater in magnitude especially in those municipalities exposed to joint operations.