Assessing geospatial models to explain the occurrence of clandestine graves in Mexico.

We present an assessment of several geospatial layers proposed as models for detecting clandestine graves in Mexico. The analyses were based on adapting the classical ROC curves to geospatial data (gROC) using the fraction of the predicted area instead of the false positive rate. Grave locations were obtained for ten Mexican states that represent the most conflicting regions in Mexico, and 30 layers were computed to represent geospatial models for grave detection. The gROC analysis confirmed that the travel time from urban streets to grave locations was the most critical variable for detecting graves, followed by nighttime light brightness and population density, whereas, contrary to the rationale, a previously proposed visibility index is less correlated with grave locations. We were also able to deduce which variables are most relevant in each state and to determine optimal thresholds for the selected variables.

The perfect storm. An analysis of the processes that increase lethal violence in Mexico after 2006.

Research on 'the War on Drugs' in Mexico finds that military interventions increase lethal violence in the country. However, these studies fail to account for other processes that may be driving the behavior of lethal violence in the Mexican municipalities. We find confirmation that these rival processes influence the relative impact that military interventions have on lethal violence. In particular, we find that seasonality in violence, competition for scarce resources and PAN's governance in the municipalities are associated with higher levels of lethal violence, as measured by the young male homicide rate. We argue that the literature may have overestimated the effect that military interventions have in lethal violence in municipalities and that other drivers of violence should be taken into account to accurately measure the impact that military interventions have on lethal violence.