Why Gun Traffickers Should Live in Arizona

A new study by Brian Knight, an economist at Brown, explores the flow of illegal firearms in America and compares the source of guns used in crimes to gun laws in and around that state.

How big is the market for illegal firearms? Pretty big. Knight writes: “ATF investigations into tracking between July 1996 and December 1998 identify over 84,000 firearms that were diverted into this secondary market (ATF, 2000).” Meanwhile, each state in America legislates its own gun laws, resulting in cross-state externalities. For example, Knight cites anecdotal evidence showing that a gun purchased legally in Virginia for $150 – $200 typically resells in New York City for $500 – $600. This is the sort of thing that keeps Michael Bloomberg up at night.

Here’s the abstract:

This paper provides a theoretical and empirical analysis of cross-state externalities associated with gun regulations in the context of the gun trafficking market. Using gun tracing data, which identify the source state for crime guns recovered in destination states, we find that firearms in this market tend to flow from states with weak gun laws to states with strict gun laws, satisfying a necessary condition for the existence of cross-state externalities in the theoretical model. We also find an important role for transportation costs in this market, with gun flows more significant between nearby states; this finding suggests that externalities are spatial in nature. Finally, we present evidence that criminal possession of guns is higher in states exposed to weak gun laws in nearby states.

Knight found that:

  • States with strong gun laws tend to have their laws weakened by states with weak gun laws.
  • States with weak gun laws tend to have their laws strengthened by states with strong gun laws.
  • State size matters — small states are more affected by trafficking, the classic example being the District of Columbia (which isn’t quite a state, but you get the idea).

About one-third of guns used in crimes come from out of state. There is a spatial aspect to the flow of illegal guns, of course, and a state with tough gun laws next to a state with weak ones is much more likely to have a higher supply of illegal firearms. So it would be ideal for gun runners to live in states like Virginia, Arizona and Missouri, unless of course we’re talking about Jax Teller in Charming, California.

Scott Mc.

I wonder if the study controls for other factors before lamenting weak gun laws? It would seem to me that states that have less guns owners to start with are more likely to pass stricter gun laws, as fewer constituents would be outspoken against such measures.

If we assume that demand for black-market weapons is stable across geographies, then states which have historically had a lower incidence of firearm ownership would necessarily have fewer potential supply chains (each gun owner represents a potential supply chain, remember, as theft is the most common means of illegally acquiring a firearm). If stricter laws are merely indicative of a market where supply of illegal firearms is already below equilibrium (for the criminals), then the laws themselves may have little or no impact on market dynamics. I would argue that states that have a naturally lower supply of guns should of course be net importers, regardless of gun legislation.

So to assume a causal relationship, that infers anything more than that products move from where there is excess supply to where there is excess demand, may be misleading. While the legislation may be an indicator of whether a particular state has excess supply or excess demand, any inference that such laws impacted the inter-state trade of illegal weapons may not be accurate.

Does lower supply of guns cause stricter gun laws, or do stricter gun laws cause a reduction in supply? States like California, which had a lower firearms ownership rate in the 1990s, succeeded in passing stricter gun control laws (weapons bans, etc.); Florida, which has a high ownership rate, succeeded in passing some of the most liberalized gun laws in the nation (they were one of the first to expand concealed carry, for instance).

Who knows, maybe this could be a jumping off point for a chapter in your next book?



I want to address this sentence: About one-third of guns used in crimes come from out of state.

What if one-third of all guns in that state come from another state, which is quite logical as the market for resell of firearms is quite large as they tend to be long-lasting goods. Then this would just mean that guns in crimes are the same as guns in usage which would say nothing special about guns in crime. But what if more than one-thirds of guns in legal usage are from out of state? Then guns used in crimes would be more likely to come from the state in which they are used than normal guns.

Neil (SM)

I think it's even simpler than that. If 1/3 of guns used in crimes come from out of state, then the other 2/3 of guns used in crime come from within the state. So then it is correct that the gun used in a crime is more likely to come from within.

None of that says anything about where the legally-used guns come from, so all of that would be speculation -- but not really relevant to the discussion I think. I imagine in many states guns from out-of-state are illegal by definition?

But I think what the paper is getting at is not so much that guns used in crimes are more likely to come from out-of-state; the authors are simply asserting that interstate weapon trafficking makes some significant contribution to gun crimes.

Scott Mc.

"I imagine in many states guns from out-of-state are illegal by definition?"

Not really - I can't think of any state that bans guns that came from other states; quite the contrary, many states exempt guns that might not otherwise comply with their own laws if they were legally possessed by someone moving into that state. Both California and Massachusetts have approved rosters for handguns, where only models listed are legal to purchase. However, both CA and MA allow off-roster guns to be imported legally by people who are moving into the state.

Some states which have an "Assault Weapon Ban" may mandate that some guns (typically rifles) be modified - you may have to change an adjustable stock to a fixed stock, for instance, or disassemble 30-round magazines and only use 10-round magazines - but assuming you're willing to make the modifications, you can still legally possess your firearm.



It appears to me that the language used here reflects a pronounced bias. If I buy a book, a computer, or a car in one state and take it to another state, it is merely a fact: I've moved. But if I buy a gun in one state and take it to another state, I'm now an illegal weapons trafficker?


If you move your car from one state to another you still need to register it in the new state. If you move your gun (or any other product) from one state to another you would also need to follow the laws for the new state.

So no bias, unless you consider that there are laws for owning/buying guns and not for owning/buying books a bias.

Scott Mc.

I think James was just pointing out that just because a gun was originally purchased in another state, it doesn't necessarily imply that anything illicit was involved in the importation.

Many guns, for instance, qualify under federal law as something called "Curios and Relics." There are a number of "03 FFL's" (Federally- licensed collectors of Curios & Relics, who are exempt from several gun control laws when purchasing a qualifying weapon). I'm sure if a Russian Makarov pistol was recovered from a crime scene after being stolen from a C&R holder, the above study would classify it as being "from out of state," even though the pistol may have never left the state's boarders after being imported from Russia.

The same is true for police trade-in weapons. If you're in the market for a S&W 4003 right now, the vast majority of those on the market are trade-ins from the Atlanta, GA police department. They're extremely common in almost every state right now, and are high quality, affordable weapons that a first-time purchaser (who is less likely than a collector to have the infrastructure in place to properly secure his weapons) might be inclined to consider buying.

If the above circumstances account for just 10-12% of firearms in this country, that would imply that it's not 1-in-3 guns that "come from out of state," but closer to 1-in-5. After you take into account people who legally move each year...the real number of illegally-imported guns is much smaller than the headline number would seem to indicate.


Eric M. Jones

Point of history--

During the prohibition era, gun-trafficking from Mexico to the US was a serious problem.


How does a state with weak gun laws (a subjective term in itself) have them "strengthened" by nearby strong gun law states? This just seems to imply that less guns are brought in from the other state, but that is logical because people do not intentionally impose higher costs upon themselves.


"...people do not intentionally impose higher costs upon themselves."

No? You might consider the recent thread about weddings, or the number of people who make solitary commutes in SUVs.

Neil (SM)

I think the point was that people do not intentionally impose higher costs upon themselves unless they expect some increase in value, perceived or real. Theoretically guns from out-of-state in AZ would just be the same thing for a higher cost -- more money, more risk of arrest, etc.

In your examples the people are getting additional value for their higher costs.


Another possibility that doesn't seem to be considered is this:

The supply of Illegal Firearms might be higher in those states where legal ownership is lower (whether due to laws, supply, or some other reason). Why? Because the armed criminal(s) is more likely to overcome a victim without a gun, and not get shot by a potential victim that does have a gun.

A criminal with an illegal gun does not have a good chance of success and being more powerful in a state where everyone owns a gun - the criminal is much more likely to be met with equal force and shot.

But a criminal with an illegal gun in a state with few guns is much more likely to be successful without being shot in return.

This could easily account for the flow of illegal weapons towards states with strict laws and low supply / ownership of legal guns.

But I would also like to point out that the study doesn't seem to make a distinction between the movement of legal guns (that are not used for criminal activity) across state borders and the movement of illegal guns across state borders. In fact, it seems to indicate that ANY movement of guns across state borders are for illegal purposes only, which will severely bias the study.



This happens in some city's in Texas. Someone will break into a house get shot and then I think house break-ins will slow for roughly 4-6 months and build up again untill another criminal gets shot. I would like to see how true or not this is.