The Association between Anti-cartel Military Intervention and Municipal Homicide Rates in Mexico, 2000–2022

Abstract Objectives Our objective was to examine the association between anti-cartel military interventions and homicide rates in Mexico. Nearly half a million people became homicide victims in Mexico in the sixteen years following President Calderón’s declaration of war against the cartels in 2007. Mexico possesses persistently high but geographically varying homicide rates, and the military is central to these anti-cartel interventions. This context presents a unique opportunity to analyze the heterogeneous violence patterns associated with intervention exposure in a quasi-experimental framework. Methods We examined the association between anti-cartel military interventions and total and gun (as a proxy for cartel-related) homicide rates in a sample of 2,429 Mexican municipalities from 2000 to 2022. We tested for multiple types of associations, specifying interventions as both “permanent” and “alternating.” We used Two-Way Fixed Effect Difference-in-Difference models to estimate the average treatment on the treated. Results We found no evidence that anti-cartel military interventions were associated with a reduction in lethal violence as intended. Instead, on average treated municipalities had higher total and cartel-related homicide rates than comparable municipalities that did not experience intervention. The results were consistent across a wide array of sensitivity tests. Conclusions We interpret our findings in the context of illegal enterprise theory, which suggests that military intervention may be associated with destabilizing criminal organizations and thus can lead to heightened competition, fragmentation, and increased violence.