US Gun Shop
Even if a background checks bill squeaks through the Senate, it stands little chance in the House, which is controlled by the GOP and dominated by conservative wings of both the Republican and Democratic parties. Reuters

Tracing the origin of guns that arm Mexico’s drug trafficking organizations has been an inexact process, but mounting data consistently points to small-scale American firearms dealers whose business has become dependent on criminal demand.

According to a new study carried out by researchers from the University of San Diego’s Trans-Border Institute and Brazil’s Igarapé Institute, approximately 2.2 percent of all U.S. firearms sold between 2010 and 2012 ended up in the hands of traffickers running weapons down to Mexico, amounting to some 253,000 guns every year.

“The Mexican authorities are patently frustrated with the relentless flow of arms and ammunition from north of the border,” the study reads.

“Our findings suggest that the scale and volume of firearms trafficking from the United States to Mexico is much higher than widely assumed,” it adds.

Previous data has focused specifically on firearms confiscated at the U.S.-Mexico border, which the authors of the study say account for only a fraction of all arms trafficking.

The USD study aims to determine arms traffic flow based on a demand curve for firearms south of the border fed by a complex set of factors and the increasing economic dependency of U.S. dealers -- whether they are aware of it or not -- on business from traffickers.

The formula for the curve relies on data such as a U.S. arms dealer’s proximity to the Mexican border and the subtraction of domestic demand for firearms from total sales.

The study found a proliferation of gun stores along the border with some 6,700 of the nation’s 51,300 arms retailers (13 percent) concentrated in the Texas, New Mexico, Arizona and California.

“The Mexican demand explains that abundance and the successful nature of the business,” said Robert Muggah, one of the study’s authors, McClatchy reported.

From 2010 to 2012, 46.7 percent of small U.S. arms dealers were dependent on some level of demand for firearms from Mexico, the study says. This increased from 37.4 percent in 1993, it adds. The current "drug war" in Mexico broke out in 2006.

The value of the illegal arms trade has also increased substantially to an estimated $127.2 million annually during the previous three years from $32 million during 1997 to 1999.

“The scale of the trade demonstrates that the United States is an important contributor to the global supply of firearms in illicit markets,” the study says. “It also draws attention to the particular function of domestic firearms regulation and the concomitant responsibilities of U.S. authorities.”

In their concluding remarks, the study’s authors suggested several regulatory measures that could be undertaken by the U.S. government to stem arms trafficking into Mexico, including a national gun registry, universal background checks and a prohibition on cash transactions for firearms purchases in the border states.

Since 2006, some 120,000 people have been killed by drug-related violence in Mexico.