Over the weekend, the below email came in from Miguel at Gun Free Zone:
Have you done a correlation/whatever is called between the number of guns in a country and the # murders and/or violent crimes?
The attachment is a list of countries and their number of guns according to the Small Arms Survey which the antis can’t bitch about because it is a group on their side. I used this wikipedia link to get the number of Homicides per country.
According to that, it only "takes" Great Britain 4,709 guns to have a homicide. The US requires 20,000 guns to have a homicide.
OK, so I have no clue about statistics and every time I open Excel I go "What kind of sorcery is this?" but I think you get the idea.
One of your graphics work there perhaps?
Attached to the email was the 2011 update to the Small Arms Survey, complete with a table supposedly showing "Civilian gun ownership for 40 countries, in descending order of averaged civilian firearms"… except, after looking at the source information for the table, it shows no such thing, so I am not even going to bother linking to the 2011 document in this post.
Anywise, the question intrigued the statistician in my mind, so here we are. We are all familiar with the tried-and-false "argument" of the anti-rights cultists that "more guns = more deaths" – a hypothesis we have already tested and found significantly wanting. However, assume for a moment that we accept that we take complete leave of our senses and logic and accept that hypothesis as true; given that basis, how many more guns does it take to yield another murder?
After all, if more guns results in more murder, then there must be some kind of metric one could build indicating that if you add X more guns to the population, you will get Y more murders. So how many firearms does it "take" to "cause" a murder?
As with all such questions, the answer is complicated. Given that most individual states in America do not document how many firearms their residents own (as they should not, and never should do), we are going to have to look farther abroad for our dataset and instead consider this question across international borders. Instead of simply limiting ourselves to the numbers included in the 2011 Small Arms Survey update, we will instead return to the original 2007 document (*.pdf warning) which documents, estimates, and straight-up guesses at firearm ownership in 178 different countries (I used the average of the Low Total From Outside Sources and High Total From Outside Sources where available, Registered if not). Of those countries, I will use the numbers for every country in North, South, and Central America; North, South, Eastern, and Western Europe; Oceania; and a few other odds and ends to round out a good sample body of 90. (Do note that some useful countries were omitted from the Survey, like Denmark, India, and Luxembourg.)
Much though I hate to use Wikipedia as a source for… anything, really, we will also use the page Miguel linked to in his email, simply because it has hundreds of countries’ statistics all in one conveniently, easily-sourced location.
So what is the end result? Probably not what you think:
(You will probably want to download this thing to view locally; it is huge, and the text is, obviously, small.)
First off, way to go Iceland for messing with the curve, by only having one murder in 2010. Bravo.
Moving on, the numbers at the far right end of the orange bar indication how many firearms there are in the country per murder transpiring in the country. Given that Iceland has somewhere around 90,000 firearms in-country and all of one murder, it’s number is obvious. America has somewhere around 270,000,000 (probably far north of that, but that is the official number) firearms and we had 12,996 murders in 2010, so it "takes" somewhere around 20775 firearms to "create" an unlawful killing. Obviously firearms do not create murders any more than spoons cause obesity, but, as I said at the beginning, we surrendered logic and reason in order to adopt the "more guns = more deaths" hypothesis and further examine it.
Now, remember that higher numbers are "better", in that it "takes" more guns to "cause" a murder. So consider the countries above us… and then the countries below us. For example, observe how the functional theocracies typically rank over us, at least if they have not suffered a war recently. Likewise, those countries with a strong history in firearms – or just an absurdly low population or population density – are up there with us or above us. Now, take a look at where the United Kingdom – the oft-vaunted example of "ideal" "gun control" – falls on the chart: apparently their firearms are four times more deadly than ours. Or how about Mexico, where private ownership of firearms is functionally impossible, but "murder" seems to be the recreational sport of choice? Hell, Fiji has functionally no guns (all of 1538, or "what I have buried in my back yard"), but they managed to crank out 23 murders despite that.
While this interesting chart does answer Miguel’s question – with the answer being "it depends" – it is also not as honest as it could be; after all, Fiji has a population of under a million souls, while Switzerland has over 7 million folks on its rolls. So how does the rate of firearm ownership affect the rate of murders in these various countries?
Wrong question. Just seeing if you all are paying attention – as always, I am not here to document that guns affect murders, or even crime in general; I am sorely equipped to do so (read: "underpaid") and the examination of that kind of causal relationship would require a lot more consideration and information than I have available at the moment. So, the right question is, "How does the rate of firearm ownership correlate to the murder rate in these various countries?" Kind of like this:
That line slanting to the lower-right and disappearing beneath the x-axis is the trendline for the datapoints, and the equation for that line tells you everything you need to know. Specifically, there is a correlation coefficient of -0.2055 between the rate of firearm ownership and the rate of murders in the 90 countries I have documented on the bar chart above. In other words, using those countries’ data from a single year as our test population, countries with higher gun ownership rates tend to enjoy lower murder rates and vice versa. However, this is a very weak correlation, and thus does not hold true in all cases.
As always, there are more forces at play here than just the number of firearms in public circulation; after all, the median household income for Switzerland is somewhere around $27,000 USD, while Mexico’s is more like $5,000 USD. Likewise, population density is not really a problem for those crazy folks in Iceland (though I would imagine other things are), but Brazil is largely uninhabited too… in a bad way for the millions of folks living there.
In any case, given the negative correlation between firearm ownership rates in various countries and murder rates in those same countries, the causality outright claimed by "more guns = more deaths" cannot exist, even across international borders. If there were even a chance of a causal relationship, the trendline in the above graphic would be sloping up to the right, rather than down, as the hypothesis would clearly indicate.
I sincerely wish there were a simple and easy way of reducing murders and other violent crimes, but the simple, honest, rational truth is that restricting/controlling/banning inanimate lumps of machined metals does not work. It has not worked before, it has not worked in other countries, and it is not working here; how about we consider alternatives, and try to find something that does work?
(Updated in 2014 with labels on the second chart.)