A new study found that nearly half of United States firearms dealers are economically dependent on demand from Mexico, while under 15 percent of illicitly trafficked arms are seized at the border, highlighting the US role in Mexican gun violence.

The study, titled "The Way of the Gun: Estimating Firearms Traffic Across the U.S.-Mexico Border," aimed to quantify the US role in feeding Mexico's gun violence, which continues to rise despite tight gun control policies and a lack of arms manufacturing in Mexico.

Researchers found that from 2010 to 2012, approximately 46.7 percent of US firearms dealers depended on business from the US-Mexico gun trade for their economic survival.

Comparing the periods 1993 to 1999 and 2010 to 2012, University of San Diego researchers found that the sale and value of firearms destined for Mexico has grown significantly. In the most recent period, 2.2 percent of US firearm sales were destined for Mexico, compared to 1.75 percent in 1993.

The actual number of firearms purchased to be trafficked across the US-Mexico border was estimated to be between 106,700 and 426,729, worth $53.7 to 214.6 million. This represents a significant growth from the 35,597 to 152,142 arms bought for trafficking between 1997 to 1999, worth $13 to 55.4 million.

Meanwhile, US and Mexican authorities were estimated to seize less than 15 percent of these firearms at the border, with the US responsible for just two percent of seizures.

The study notes that, according to 2012 Mexican military estimates, just a third of a percent of firearms in Mexico are legally registered and 90 percent are used for criminal activity.

InSight Crime Analysis

A 2012 US government study found that 70 percent of firearms recovered in Mexico over a five-year period could be traced to the US.

The current study deepens understanding of this trade by quantifying US profits from Mexican firearms trafficking, and providing a percentage, rather than a real number, of arms seized. The numbers indicate a lack of interest -- or at least ineffectiveness -- on the part of the US in stopping this illicit trade and show how little effect tight gun restrictions in one country have if a neighbor country serves as a ready supplier.

Loose state gun and ammunition control laws in the southwestern states contribute significantly to the problem, as highlighted by a 125-fold increase in the seizure of ammunition at the Arizona-Mexico border from 2007 to 2011.

In recent years there have even been accusations Mexican cartel the Zetas have acquired arms through a US government program intended to monitor gun sales, while the US Bureau of Alcohol Firearms and Tobacco (ATF) controversially supplied weapons to arms dealers in a mostly failed attempt to trace their progress through the Mexican underworld as part of operation "Fast and Furious."

A January 2013 ruling aimed to tighten US control over illicit arms trafficking. Following the ruling, Arizona, Texas, California and New Mexico gun dealers are required to report individuals who make multiple purchases of semi-automatic rifles.