02/01/2022 (written by vmateoszuniga) – Justice in Mexico released its latest working paper “The Impact of State-level U.S. Legalization Initiatives on Illegal Drug Flows” by Vivian Mateos Zúñiga and David A. Shirk. This study analyzes the relationship between cannabis legalization in the United States and the flows of illicit drugs across the U.S.-Mexico border. It specifically focuses on the effects of an increase in the percentage of the U.S. population with legal access to cannabis on the amount of illicit cannabis eradication and seizures in Mexico and U.S. border seizures, as well as flows of other drugs that may have supplanted cannabis trafficking.
The percentage of the U.S. population with access to legal cannabis is measured using state-by-state intercensal data from the U.S. Census Bureau while illicit drug production and trafficking are measured using a variety of proxy variables. These include data from the Mexican President’s Annual Report which contains figures on drug eradication and seizures throughout Mexico, as well as seizure data from the U.S. Customs and Border Protection (CBP). Combined, these figures give an estimate of the amounts of narcotics being cultivated and trafficked.
The authors hypothesized that as the percentage of the population with legal access in the United States increased, there would be a decrease in illicit cannabis production in Mexico and a decrease in illicit cannabis trafficking into the United States. Conversely, the authors also predicted an increase in the production of other illicit drugs in Mexico and the trafficking of other illicit drugs into the United States. Combined, the hypotheses allow for a comprehensive look at the effects of cannabis legalization on both the production and trafficking of multiple drugs.
Data and Analysis
The study combines qualitative and quantitative analysis including research regarding cannabis prohibition over time as well as the history of state-wide cannabis legalization in recent decades. To measure the relationship between the variables, the authors regressed the dependent variables for Mexican eradication and seizures as well as seizure figures from CBP against the percentage of the U.S. population with legal access to cannabis to find the statistical significance of the relationship.
The authors found a general decline in cannabis eradication in Mexico from 2001 to 2020, as well as a general decline in cannabis seizures by Mexican authorities within that same time frame. While seizure data from CBP is not as extensive or widely available, the authors also noted a decline in cannabis seizures at the U.S. border. In fact, in 2009, the 3.3 million pounds of cannabis seized represented 98% of the 3.4 million pounds of illicit drugs seized at U.S. borders. By 2020, illicit cannabis seizures dropped to 600,000 pounds and accounted for a little over 70% of the 846,658 pounds of narcotics seized by U.S. border agents.
The study also found statistically significant evidence that cannabis seizures made by both Mexican and U.S. authorities have declined in relation to the increase in access to legal cannabis in the United States. The authors’ findings show that for every 1% increase in the U.S. population that has gained access to legal medical or recreational cannabis, the authors found at least a 1.66% decrease (573.3 hectares) in the amount of cannabis eradicated by Mexican authorities. Additionally, for every 1% increase in the U.S. population that gains access to legal cannabis, there is at least a 1% decrease in the amount of cannabis seized annually by U.S. authorities between ports of entry and a decrease of at least 0.8% in seizures at U.S. ports of entry.
Furthermore, the study supported the authors’ hypotheses regarding the increase in the seizures of other illicit drugs, particularly in the cases of heroin, methamphetamine, and fentanyl. In fact, for each 1% increase in the U.S. population with access to legal cannabis, the authors estimate an increase of 428kg of methamphetamine seized by Mexican authorities, an increase of 332 pounds seized between ports of entry, and a nearly 3,000 pounds increase at ports of entry. The authors did not find evidence to support similar claims regarding cocaine.
While these results appear to validate the claims of many cannabis legalization advocates who theorized that legalization would harm Mexican cartels and their revenue streams tied to cannabis, the data also point toward a worrisome shift toward the trafficking and production of synthetic drugs in an effort to diversify their income. The authors argue that these findings are relevant to the future of drug policy reform and potential unintended consequences.
