Expert Commentary

Estimating firearms trafficking across the U.S.-Mexico border

2014 study published in Journal of Economic Geography using data on dealers with Federal Firearms Licenses to sell small arms (FFLs) to understand the flow of arms across America's southern border.

The United States is not only one of the leading gun manufacturers in the world, it’s also one of the largest importers. According to the Bureau of Alcohol, Tobacco and Firearms (ATF), 8.6 million guns came out of U.S. factories in 2012, more than 2.5 times the number produced a decade earlier. Of these, 287,544 were exported, while 4.8 million were imported, primarily from Brazil, Austria, Germany, Italy, Croatia, Turkey and Canada — in all, a net gain of 13 million firearms in a single year.

The end result is a lot of weapons: 2013 research from Cleveland State University estimated that there are between 262 and 310 million privately owned firearms in the United States, while a 2007 study based on the General Social Survey put the number at 218 million. Despite occasional short-term spikes in gun sales, however, the overall trend in gun ownership has been a decline: In 1980, just over 50% of households possessed a gun, but by 2010, the rate had fallen to 35%. One factor is that gun ownership has become more concentrated, with 48% of those who do own guns reporting that they had five or more.

Compared to other developed nations, the United States has relatively few limits on firearm ownership, and is just one of three nations to enshrine the right to bear arms in its constitution. The number of states with “right to carry” laws has also risen, even though a 2015 study found that they may increase rather than decrease gun violence. Even with the relatively limited regulations in the United States, a survey of gun dealers in 2011 revealed that approximately 37,000 attempts were made to purchase weapons illegally the previous year, often through “straw buyers.”

One question is what the “spillover” effects are on bordering countries. In particular, while Mexico’s constitution also includes the right to bear arms, the country’s army oversees all individual firearms sales. Sales of firearms, ammunition and explosives are controlled, and all weapons are required to be registered. However, the military estimated in 2012 that less than 1% of the firearms in Mexico are legally registered and 90% of all firearms are used for criminal purposes.

Research and anecdotal evidence indicate that there are significant numbers of firearms smuggled across the U.S.-Mexico border, but the exact number has been hard to quantify. A 2014 study published in Journal of Economic Geography, “The Way of the Gun: Estimating Firearms Trafficking Across the U.S.-Mexico Border,” sought to better understand the flow of arms across America’s southern border. For the study, the researchers — Topher L. McDougal, David A. Shirk, Robert Muggah and John H. Patterson of the University of San Diego — analyzed data over two periods, 1993-1999 and 2010-2012, from dealers with Federal Firearms Licenses to sell small arms (FFLs). The dataset included geographic information, allowing them to “estimate the realized demand for firearms based on the distance by road from the nearest point on the U.S.-Mexico border.”

The study’s findings include:

  • Nearly 2.2% of U.S. domestic arms sales between 2010 and 2012 were attributable to firearms trafficked across the U.S.-Mexico border. That represents 212,887 weapons that are purchased annually and then trafficked to Mexico.
  • The mid-range estimate suggests that the combined seizures of roughly 37,000 firearms by Mexican and U.S. authorities represent roughly 18.2% of the weapons bought for trafficking in recent years.
  • Of the 81.8% of trafficked weapons that are unaccounted for, many may pass through Mexico and are destined for other countries in Central and Latin America.
  • In 2007 the ATF traced 2,455 firearms confiscated in Mexico, and found that 1,805 of them, or 73.5%, came from dealers in three of the four border states: Arizona, California and Texas.
  • In the border region there are approximately 6,700 FFLs, or 12.5% of all registered gun dealers in the United States. This represents three gun dealers for every mile of the U.S.-Mexico border.
  • The number of U.S. FFLs was approximately 150,000 in 1975, peaked at around 250,000 in 1993, and then fell precipitously. As of 2011, there were approximately 50,000 FFLs.
  • The fall in the number of FFLs is attributed to legislation to reduce violent crime, including the Brady Handgun Violence Prevention Act (1993), the federal Assault Weapons Ban (1994), Violent Crime Control and Law Enforcement Act (1994) and the FBI’s National Instant Criminal Background Check System (1998). “Each of these developments imposed certain reporting and overhead costs on FFLs,” concentrating sales in a dwindling number of larger dealers.
  • Given the falling number of U.S. FFLs overall and the rising percentage in the border region, “the demand effect of U.S.-Mexico border proximity [is] clearly visible.”

“Our study demonstrates that it is possible to leverage the locational decisions of retailers to estimate the volume of an illicit trade,” the authors conclude. They note that further research needs to be done to generate a “more direct spatial link between the use of firearms in Mexico (e.g. municipality-level homicide statistics) and the sale of firearms in U.S.”

Related research: A 2013 study published in the journal Injury Prevention, “Legal Status and Source of Offenders’ Firearms in States with the Least Stringent Criteria for Gun Ownership,” analyzes a national survey of inmate offenders, focusing on those in the 13 states with the weakest gun control laws. Also of interest is “Profiling Gun Dealers, Pawnbrokers and Illegal Weapons Sales,” which looks at two 2013 studies based on a national survey of gun sellers, and includes data on the number of attempted illegal firearms purchases.


Keywords: firearms, weapons, gun trafficking, pawnbrokers, gun smuggling, crime, arms manufacturing, Latin America

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