Everybody’s Lying About the Link Between Gun Ownership and Homicide

Source: Everybody’s Lying About the Link Between Gun Ownership and Homicide

There is no clear correlation whatsoever between gun ownership rate and gun homicide rate. Not within the USA. Not regionally. Not internationally. Not among peaceful societies. Not among violent ones. Gun ownership doesn’t make us safer. It doesn’t make us less safe. The correlation simply isn’t there. It is blatantly not-there. It is so tremendously not-there that the “not-there-ness” of it alone should be a huge news story.

And anyone with access to the internet and a basic knowledge of Microsoft Excel can check for themselves. Here’s how you do it.

First, go to the Wikipedia page on firearm death rates in the United States. If you don’t like referencing Wikipedia, then instead go to this study from the journal Injury Prevention, which was widely sourced by media on both the left and right after it came out, based on a survey of 4000 respondents. Then go to this table published by the FBI, detailing overall homicide rates, as well as gun homicide rates, by state. Copy and paste the data into Excel, and plot one versus the other on a scatter diagram. Alternately, do the whole thing on the back of a napkin. It’s not hard. Here’s what you get:

This looks less like data and more like someone shot a piece of graph paper with #8 birdshot.

If the data were correlated, we should be able to develop a best fit relationship to some mathematical trend function, and calculate an “R^2 Value,” which is a mathematical way of describing how well a trendline predicts a set of data. R^2 Values vary between 0 and 1, with 1 being a perfect fit to the data, and 0 being no fit. The R^2 Value for the linear trendline on this plot is 0.0031. Total garbage. No other function fits it either.

I embellished a little with the plot, coloring the data points to correspond with whether a state is “red,” “blue,” or “swing,” according to the Romney-Obama era in which political demarcations were a little more even and a little more sensical. That should give the reader a vague sense of what the gun laws in each state are like. As you can see, there is not only no correlation whatsoever with gun ownership rate, there’s also no correlation whatsoever with state level politics.

But hey, we are a relatively unique situation on the planet, given our high ownership rates and high number of guns owned per capita, so surely there’s some supporting data linking gun ownership with gun homicide elsewhere, right?

So off we go to Wikipedia again, to their page listing countries by firearm related death rates. If Wikipedia gives you the willies, you’re going to have a harder time compiling this table on your own, because every line in it is linked to a different source. Many of them, however, come from http://www.gunpolicy.org. Their research is supported by UNSCAR, the UN Trust Facility Supporting Cooperation on Arms Regulation, so it is probably pretty reasonable data. They unfortunately do not have gun ownership rates, but do have “guns owned per 100 inhabitants,” which is a similar set we can compare against. And we drop that into Excel, or use the back of our napkin again, and now we are surely going to see how gun ownership drives gun homicide.

Well that’s disappointing.

Remember we are looking for an R^2 value close to 1, or hopefully at least up around 0.7. The value on this one is 0.0107. Garbage.


So let’s briefly recap. Gun Murder Rate is not correlated with firearm ownership rate in the United States, on a state by state basis. Firearm Homicide Rate is not correlated with guns per capita globally. It’s not correlated with guns per capita among peaceful countries, nor among violent countries, nor among European countries. So what in the heck is going on in the media, where we are constantly berated with signaling indicating that “more guns = more murder?”

One: They’re sneaking suicide in with the data, and then obfuscating that inclusion with rhetoric.
This is the biggest trick I see in the media, and very few people seem to pick up on it. Suicide, numerically speaking, is around twice the problem homicide is, both in overall rate and in rate by gun. Two thirds of gun deaths are suicides in the USA. And suicide rates are correlated with gun ownership rates in the USA, because suicide is much easier, and much more final, when done with a gun. If you’re going to kill yourself anyway, and you happen to have a gun in the house, then you choose that method out of convenience. Beyond that, there’s some correlation between overall suicide and gun ownership, owing to the fact that a failed suicide doesn’t show up as a suicide in the numbers, and suicides with guns rarely fail.


Two: They’re cooking the homicide data.
The most comprehensive example of this is probably this study from the American Journal of Public Health. It’s widely cited, and was very comprehensive in its analytical approach, and was built by people I admire and whom I admit are smarter than me. But to understand how they ended up with their conclusions, and whether those conclusions actually mean what the pundits say they mean, we have to look at what they actually did and what they actually concluded.

First off, they didn’t use actual gun ownership rates. They used fractional suicide-by-gun rates as a proxy for gun ownership. This is apparently a very common technique by gun policy researchers, but the results of that analysis ended up being very different from the ownership data in the Injury Prevention journal in my first graph of the article. The AJPH study had Hawaii at 25.8% gun ownership rate, compared to 45% in IP, and had Mississippi at 76.8% gun ownership rate, compared to 42.8% in IP. Could it be that suicidal people in Hawaii prefer different suicide methods than in Mississippi, and that might impact their proxy? I don’t know, but it would seem to me that the very use of a proxy at all puts the study on a very sketchy foundation. If we can’t know the ownership rate directly, then how can we check that the ratio of gun suicides properly maps over to the ownership rate? Further, the fact that the rates are so different in the two studies makes me curious about the sample size and sampling methods of the IP study. We can be absolutely certain that at least one of these studies, if not both of them, are wrong on the ownership rate data set. We know this purely because the data sets differ. They can’t both be right. They might both be wrong.


Series roundup:

In the second article, we unpack “gun death” statistics and look carefully at suicide.

In the third article, we debunk the “gun homicide epidemic” myth.

In the fourth article, we expand upon why there is no link between gun ownership and gun homicide rate, and why gun buybacks and other gun ownership reduction strategies cannot work.

In the fifth article, we discuss why everyone should basically just ignore school shootings.

The sixth article presents a solution free of culture wars, and the finale isn’t about guns at all.

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