According to a recent National Journal analysis of data from 2013, "the states that im­pose the most re­stric­tions on gun users also have the low­est rates of gun-re­lated deaths, while states with few­er reg­u­la­tions typ­ic­ally have a much high­er death rate from guns." Bearing in mind that correlation does not prove causation, what should we make of this conclusion?

Notably, "gun-related deaths" include not only homicides but suicides, accidents, and "legal intervention involving firearms." In fact, suicides account for three-fifths of gun-related deaths in the United States, twice as many as homicides do. That breakdown is obviously relevant to the question of whether particular laws can be credited with reducing gun-related deaths. Making it harder to buy a handgun might affect suicides, for instance, while making it harder to carry a handgun in public or easier to beat homicide charges with a self-defense claim probably would not.

Focusing on homicides can have a dramatic impact on a state's rank. Wyoming, for instance, has a high suicide rate but a low homicide rate. The District of Columbia, by contrast, has a low suicide rate but a high homicide rate.

According to National Journal, the six states with the lowest rates of gun-related deaths in 2013, ranging from 2.6 to 5.7 per 100,000, were Hawaii, Massachusetts, New York, Connecticut, Rhode Island, and New Jersey, which do indeed have relatively strict gun policies as measured by requirements for buying and carrying handguns. National Journal also considered whether states impose a duty to retreat on people attacked in public places, which all six of these states do.

Once you get past those six states, the hypothesis that low gun death rates go hand in hand with strict gun control starts to break down. New Hampshire, with a gun death rate just a little higher than New Jersey's, has permissive gun policies. Likewise Minnesota, Washington, Vermont, Wisconsin, and South Dakota, all of which have gun death rates of 10 or less per 100,000. New Hampshire and Minnesota have lower rates than California, Illinois, the District of Columbia, and Maryland, all of which have substantially stricter gun rules.

At the other end of the list, Alaska, Louisiana, Mississippi, Alabama, Arkansas, and Wyoming have both permissive gun policies and high gun death rates, ranging from around 17 to nearly 20 per 100,000. But of these six states, only Louisiana has a very high gun murder rate (based on 2010 data). The rate in Mississippi is fairly high but still lower than in D.C. or Maryland, which have much stricter gun laws. Alaska, Wyoming, Alabama, and Arkansas have lower gun murder rates than California, which has more gun restrictions.

Although its overall analysis looks at all gun-related deaths, National Journal (after some prodding, judging from the note in italics) focuses on gun homicides in charts that compare states based on three policies: whether they impose a duty to retreat, whether they require background checks for all gun sales, and whether they issue carry permits to anyone who meets a short list of objective criteria. Excluding suicides makes sense for at least two of those comparisons, since you would not expect the rules for self-defense or for carrying guns in public to affect suicide rates. Background checks conceivably could, since among other things they are supposed to prevent gun purchases by people who were forcibly subjected to psychiatric treatment because they were deemed a threat to themselves.

According to the first chart, the average rate of gun-related homicides in states with "some form of 'stand your ground' law" in 2013 was 4.23 per 100,000, compared to 3.08 in the other states. (Oddly, Arkansas is included in the former category, although its "stand your ground" law was not enacted until this year.) States that did not require background checks for private sales also had a higher average gun homicide rate: 4.02 per 100,000, compared to 3.41 for the other states. But the average rates were the same (3.78 per 100,000) regardless of whether states had discretionary or "must issue" carry permit policies, which is consistent with the observation that permit holders rarely commit violent crimes.

Some states were excluded from these analyses, and the reason is revealing. The fine print at the bottom of the charts says "Alaska, Idaho, Maine, Montana, New Hampshire, North Dakota, South Dakota, Vermont, and Wyoming had too few homicides in 2013 to calculate a reliable rate" (emphasis added). These are all states with permissive gun laws, and three of them are among the seven states with the highest overall gun death rates, which highlights the importance of distinguishing between suicides and homicides. Had National Journal's main analysis excluded suicides, some of the states with few gun controls, including Alaska and Wyoming, would have looked much safer.

"The states with the most gun laws see the fewest gun-related deaths," say the headline and subhead over the National Journal post, "but there's still little appetite to talk about more restrictions." The implication is that the data prove a cause-and-effect relationship. But the question of whether stricter gun control policies cause lower gun death rates cannot be addressed by this sort of static analysis. Gun laws obviously are not the only way in which Alaska, Louisiana, Mississippi, Alabama, Arkansas, and Wyoming differ from Hawaii, Massachusetts, New York, Connecticut, Rhode Island, and New Jersey. Furthermore, while the latter states have both low suicide and low homicide rates, the former states (with the notable exception of Louisiana) are distinguished mainly by high suicide rates.

To get a clearer idea of what's going on, you would at least want to see whether the adoption of certain gun controls is associated with reductions in gun death rates, as compared to pre-existing trends in the states that adopt them and ongoing trends in the rest of the country. In any case, it clearly is not true that permissive gun laws are inevitably accompanied by higher gun death rates, especially if you focus on homicides, which is the main threat cited by proponents of new gun controls.