Policy Analysis without Causal Identification: Gun Ownership and State Terror (Part 1)
Like many Americans, we are saddened and sickened by the recent shootings in Aurora and Oak Creek. Like many Americans, we have also been discussing (among ourselves, and with friends) the prevalence of firearms in the United States. There are more guns in America per capita than in another other country in the world. And we also live in a very violent society, especially relative to our level of socioeconomic development. It is natural to wonder if guns are partially responsible for this violence, and to think about what the associated costs of gun control might be.
This is a two-part post in which I will tackle one common defense of America’s liberal firearms laws: popular defense against state terror. A broader methodological point will be to show that even without causal identification, it is easy to produce findings that should shape our understanding of public policy, which is contrary to the idea that only causal identification produces policy relevance. (More on that in the next post.)
Our good friend Matt Glassman is one very articulate defender of (some forms of) gun ownership rights. One argument that Matt finds particular compelling is that an armed society can protect itself against tyranny or state terror. Matt puts it best:
I swear, you mention the idea that gun ownership protects people from state tyranny, and pretty much every liberal immediately makes some joke about Joe Sixpack stopping a U.S. military tank with his handgun. But I think this precisely misreads the situation on two levels. The first is the factual: anyone who has ever watched the youtube videos from Iran knows that the tyrannical state doesn’t maintain its grip by employing tanks everywhere; there’s simply not enough money to do that. Instead, it relies on thugs and other ill-trained militia to terrorize citizens with knives, clubs, and small arms. You watch the video of a man being assaulted on his own front lawns by one or two state thugs with knives and clubs, and it become self-evident that such practices simply would not be possible in a society with as many homeowner firearms as the United States.
It just so happens that we here at Indolaysia have lived under authoritarian rule—the soft authoritarianism of contemporary Malaysia, where the state isn’t tyrannical but where state terror can, and has, cropped up from time to time. Let’s not pretend that we faced anything like a threat to our physical safety from the Malaysian state. But some people in Malaysia have. Our sense is that arming Malaysian civilians would not protect them against the terror that they face. But we could be wrong.
One way to check is to collect a broad range of data on state terror and gun ownership. Is it true that countries with lots of guns tend to have less state terror? First let’s look at the data on private gun ownership. I gathered this from the Small Arms Survey, using 2007 data.
The U.S. really does have a lot more privately-held firearms than any other country, relative to our population.
But is this an essential part of our defense against state tyranny? If so, we’d expect that overall, countries with lower levels of gun ownership are more subject to the tyranny of the state than than countries with high levels of gun ownership. Let’s compare the (natural log of) privately held arms per 100 people with some standard indices of state terror. Take first some rankings developed from Amnesty International. These are 2000-07 averages of a yearly index that ranges from 1 – 5, with 1 the “worst” for state terror and 5 the “best.” (Data are from the Political Terror Scale.) To illustrate another important distinction, I’ve graphed the democracies in blue, and the dictatorships in red, using the Cheibub and Gandhi binary regime classification.
The overall trend line (in black) shows that there’s a positive relationship overall between gun ownership and freedom from state terror. But these data also don’t make the U.S. look very good in the comparative context. We aren’t as free from terror as we think we are. So let’s use data collected by the State Department itself about political terror worldwide.
Again, a modest positive relationship between gun ownership and freedom from state terror. We can repeat this further, if we like, for an index of civil liberties.
The same pattern continues to hold. Now looking at these three figures, we can see a couple of conclusions.
- There is a modest positive relationship between gun ownership and freedom from state terror. This is important.
- There is also clear evidence that democracies terrorize less than dictatorships. (The blue countries tend to be further to the right than the red ones, on average.)
- The United State is a major outlier. There are plenty of examples of countries that are equally as free from state terror but which do not have nearly the same level of private gun ownership.
Taken together, this makes me skeptical that broad ownership of guns by citizens is much of a defense against state terror. It is hard to conclude that the level of gun ownership that the United States sees today is necessary to defend against tyranny. We can even repeat the exercise for other more precise indicators of state terror.
In fact, you look at these indicators and you see that the U.S. doesn’t even really do that well, even with all of our guns.
A Closer Look
But does gun ownership help, on the margins? Let’s run some simple regressions.
|ln(GDP per capita)||0.335***||0.455***||0.357***|
|t-statistics in parentheses. * p < 0.05, ** p < 0.01, *** p < 0.001.|
Consistent with the graphical results, there is an unconditional correlation between gun ownership and freedom from political terror. This correlation is statistically significant. But it disappears once we control for two other standard determinants of rights: democracy (measured as before) and economic development (measured as the log of GDP per capita, 2007-09, from the World Development Indicators).
The conclusion that this suggests is that the United States is relatively free from state terror because it is a developed democracy, not because we allow our citizens broad freedoms to arm themselves.
Of course, these are not estimates of the causal effect of gun ownership (or anything else) on state terror. These are conditional correlations, and there are plenty of reasons why we might believe that the causal relations here are more complicated than what this discussion has implied. More in the next post on what those threats to causal inference are, and how we ought to go about drawn policy recommendations from messy conditional correlations such as these.
Finally, to recreate these figures (and more) and to recreate these analyses (and more), you can download my Stata .do file here. Just put it in a folder with the path c:\data\guns_and_terror, make sure you’re connected to the internet, and run it.