Drug warsMexican drug war may have increased homicide rates

Published 8 April 2015

The Mexican government has been fighting an internal war against drug traffickers. A 2013 report by Human Rights Watch estimates 60,000 people were killed between 2006 and 2012 as a result of the military interventions and drug cartels fighting each other for control of territory. A new statistical analysis suggests that, in the short term, the Mexican government’s war against drugs increased the average murder rate in regions subjected to military-style interventions.

A new statistical analysis suggests that, in the short term, the Mexican government’s war against drugs increased the average murder rate in regions subjected to military-style interventions.

The study was conducted by Valeria Espinosa, a quantitative analyst at Google and a 2014 doctoral graduate of Harvard University’s statistics department, and Donald B. Rubin, Harvard University John L. Loeb Professor of Statistics.

The paper is published in the American Statistician, a journal of the American Statistical Association (ASA).

The Mexican government — beginning in December 2006 during former President Felipe Calderón’s term and continuing through current President Enrique Peña Nieto’s administration — has been fighting an internal war against drug traffickers. A 2013 report by Human Rights Watch estimates 60,000 people were killed between 2006 and 2012 as a result of the military interventions and drug cartels fighting each other for control of territory.

An ASA release reports that to determine the drug war’s effect on the homicide rate in the affected areas, the study compares the homicide rate in the first year after the military intervention in each affected region to the expected homicide rate for that same year had there not been an intervention.

Espinosa and Rubin conducted statistical analyses of eighteen regions affected by military interventions. Those regions — designated by the name of their major city — are Tijuana, Nogales, Madera, Juárez, Pánuco, Reynosa, Bustamante, Guadalupe, Villa de Cos, Teúl, Rincón de Romos, Sinaloa, Tepic, La Piedad, Celaya, Apatzingán, Coahuyana, and Acapulco.

Espinosa and Rubin used public data compiled by three well-respected sources in Mexico for their analysis:

  • National Institute of Statistics and Geography, the country’s national statistical agency
  • Center of Research for Development, a nonprofit think tank that conducts research and proposes policy options for Mexico’s economic and democratic development
  • Official website of Mexican President Felipe Calderón (2006-12) (note: This data, no longer publicly available, was publicly accessible until the end of Calderón’s term in December 2012)

The duo analyzed the data to determine whether military interventions in the country’s regions increased the homicide rates beyond what the expected homicide rate would have been without the interventions. For the purposes of the study, an intervention is defined as a confrontation between government forces and organized crime that resulted in three or more civilian deaths; in addition to its normal definition, civilians also could refer to drug cartel members.