Melissa Dell on trafficking networks and the Mexican drug war

This is the abstract, from a very smart and brave woman:

Drug trade-related violence has escalated dramatically in Mexico during the past five years, claiming 40,000 lives and raising concerns about the capacity of the Mexican state to monopolize violence. This study examines how drug traffickers’ economic objectives influence the direct and spillover effects of Mexican policy towards the drug trade. By exploiting variation from close mayoral elections and a network model of drug trafficking, the study develops three sets of results. First, regression discontinuity estimates show that drug trade-related violence in a municipality increases substantially after the close election of a mayor from the conservative National Action Party (PAN), which has spearheaded the war on drug trafficking. This violence consists primarily of individuals involved in the drug trade killing each other. The empirical evidence suggests that the violence reflects rival traffickers’ attempts to wrest control of territories after crackdowns initiated by PAN mayors have challenged the incumbent criminals. Second, the study accurately predicts diversion of drug traffic following close PAN victories. It does this by estimating a model of optimal routes for trafficking drugs across the Mexican road network to the U.S. When drug traffic is diverted to other municipalities, drug trade-related violence in these municipalities increases. Moreover, female labor force participation and informal sector wages fall, corroborating qualitative evidence that traffickers extort informal sector producers. Finally, the study uses the trafficking model and estimated spillover effects to examine the allocation of law enforcement resources. Overall, the results demonstrate how traffickers’ economic objectives and constraints imposed by the routes network affect the policy outcomes of the Mexican Drug War.

The link to her papers — all of which look interesting — is here.  She is currently on the job market from MIT, and I will be serving up some further posts on a few of the more interesting job market papers this year.  The original pointer is from Chris Blattman.

Here is a good summary and discussion from Ray Fisman:

Dell conjectures—based on anecdotal evidence about the drug war—that police efforts tend to weaken a cartel’s grip on a town just enough that competing traffickers see an opening to come in and fight for control of the town. Indeed, when a rival cartel controls a neighboring town, the effect of a PAN win on the drug-related homicide rate is several times higher.


Drug confiscations in the communities where Dell predicts traffickers will relocate to following a crackdown increase by about 20 percent in the months following close PAN victories. It’s a reminder that crime fighting is a bit like Whac-A-Mole—smothering traffickers’ activities in one locale merely causes them to shift their operations elsewhere. Dell finds that drug-related homicides also go up in places that her model predicts will lie on traffickers’ new paths from Mexican drug labs to the U.S. border.


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