Understanding the Interstate Export of Crime Guns : A Gravity Model Approach

In 2009 the Bureau of Alcohol, Tobacco, Firearms and Explosives successfully traced over 145 thousand guns recovered at crime scenes in the U.S. Of these guns, more than 43 thousand were originally sold in a different state from which they were recovered. What factors may explain the interstate movement of these crime guns? This paper uses the well-known gravity model of international trade to estimate interstate flows of illegal guns. Empirical results show that, like trade of goods and services between nations, the movement of illegal guns between states is proportionate to the economic sizes of trading partners and is inversely proportionate to the distance between them. In addition, the presence of gangs in one or both states tends to increase the flow of illegal guns. Lastly, differences in state gun laws tend to affect trade flows with illegal guns flowing from states with ‘weak’ gun laws to states with ‘strict’ gun laws