Shawn P. Swanson - Research

JOB MARKET PAPER

Declining Deadly Demand? The Impact of US Marijuana Liberalization on Violence in Mexico [PDF]

Abstract

Abstract: Marijuana demand in the United States historically provided drug cartels with a thriving export market, fueling marijuana cultivation and violence in Mexico. However, the liberalization of marijuana laws in the US led to an explosion of marijuana production in the US, lowering demand for marijuana imports from Mexico, ceteris paribus. Using a sample of over 2,300 rural municipalities from 1996-2018, I compare the impacts of US liberalization on Mexican municipalities more suitable to marijuana cultivation relative to those less suitable. These results show US marijuana laws have led to a large and statistically significant reduction in both marijuana cultivation and gun-related homicides in Mexico as well as an increase in legal agricultural output. Through 2018, US liberalization induced a further decrease in marijuana cultivation of 27 percentage points in a municipality in the top decile of suitability compared to one of average suitability, a further decrease in gun-related homicides of 19 percentage points, and a further increase in legal agricultural output of 9 percentage points. The increase in legal agricultural output provides evidence that these poor rural municipalities look to replace the income lost to marijuana production in the US. By isolating exogenous variation in marijuana cultivation in Mexico, I show a 10% decrease in cultivation decreases gun-related homicides 1-6%. These findings directly tie US drug demand to violence in Mexico.

WORKING PAPERS

The Interaction of State and Federal Laws: Evidence from Medical Marijuana [PDF]
Revise and Resubmit, Journal of Law and Economics

Abstract

Early state medical marijuana laws (MMLs) were met with continued federal enforcement of the Controlled Substance Act (CSA). However, in 2009, the federal government began to cede enforcement to the states, which significantly reduced the risk of prosecution faced by marijuana producers and distributors to serve the legal medical market. This research shows that the impacts of MMLs were attenuated prior to the change in enforcement, after which there was a dramatic decline in the illegal market, with marijuana border seizures plummeting, and a concurrent surge in the legal market. Given this, I ask how these changes affect the impacts of MMLs on heavy marijuana use in adults and adolescents. Using the Treatment Episodes Data Set (TEDS), I show that after the change in federal enforcement MMLs increase heavy marijuana use in adults; however, adolescent use is unaffected by MMLs both before and after the change in federal enforcement.

Is there a Link between Undocumented Immigrants and Illegal Drug Flows? [PDF]

Abstract

Mexico is the primary wholesale supplier of illegal drugs to the US market, yet little is known about drug smuggling networks and the extent to which they overlap with migrant networks. Some policy makers suggest tighter immigration policy as a means of controlling drug trafficking. Therefore, this paper asks whether undocumented Mexican migration flows or migration networks are associated with the flow of marijuana into US communities using two distinct empirical strategies. The first strategy tests whether, on average, marijuana flows from a Custom and Border Patrol (CBP) sector further impact the prevalence of marijuana in US states that receive a greater share of that sector's undocumented Mexican immigrants. In the second strategy, I test whether, on average, marijuana flows from a Mexican state further impact the prevalence of marijuana in US states to which they have stronger migration ties relative to US states to which they have weaker ties. Both empirical approaches produce null results, which suggests that neither migration flows nor migration networks play a role in marijuana smuggling. This implies tighter immigration policies are unlikely to impact marijuana trafficking.

WORKS IN PROGRESS

Technology at the Border: Apprehension Rates, Coyote Prices, and Migration

Correlates or Consequences? Adolescent Marijuana Use and Later Life Outcomes