Those who know me understand my deep and passionate hatred for the misuse of statistics. So when the President starts arguing for increased gun control based on numbers that wouldn’t be acceptable in a high school statistics course, I start throwing things at the flat screen. Thankfully, I also have a wonderful outlet called TTAG where I can outline exactly how full of crap that 40% figure that’s getting thrown around is . . .
One of the current focal points of the push for more gun control laws is that universal background checks. Ostensibly, it’s sold as a way to keep guns out of the hands of criminals and others who shouldn’t have them. But since mandatory background checks would be useless without a national gun registry, it makes me think that something else is afoot. Nevertheless, the argument that civilian disarmament proponents have latched onto is that 40% of all gun sales are currently completed without a background check. Even President Obama has used the figure.
Studies estimate that nearly 40 percent of all gun sales are made by private sellers who are exempt from [background checks]. (Jan. 16, 2013)
Studies? Really? Exactly which studies would those be? Turns out that this figure is based on a 1994 study by The Police Foundation that surveyed a whopping 251 people.
To give you how statistically bogus a sample size that small is, in order to be meaningful to 95% with a confidence interval of +/- 1, you would have needed to survey, at a minimum, 9,604 people at 1994’s U.S. population total. In this case, the confidence interval was more than +/- 6. That means the study wasn’t even approaching mere plausibility in terms of accuracy.
Let me make this even better. According to a recent analysis of the exact same study, the Washington Post concluded that the study actually indicates that private sales account for AT MOST 22% of sales. In 1994. So, even if we accept that the study is accurate (which it ain’t), the way in which it is being used in the media and by our own President is absolutely incorrect.
This is an abuse of statistics to a level that would make my high school math teacher want to chuck erasers at people.
The survey is so old that it can no longer be plausibly applied to the current situation, especially given that so many laws have been passed since this survey was completed that further restrict the ability for people to obtain a firearm without a background check.
Even setting aside that fact for a second, the results themselves are being misrepresented. The survey DOES NOT say that 40% of gun sales happen without a background check. It at most indicates 14 – 22% of sales are conducted in that manner. Of course, that’s +/- 6 percentage points due to the minuscule sample size.
This survey has nothing whatsoever to do with the current state of affairs in the United States. It’s an outdated, poorly designed study, one that would be laughed out of high school, and yet it it’s being held up as gospel in the gun control debate. It’s also indicative of just how far and how deep the gun control activists will go to find something — ANYTHING — that backs up their claim. And they have to resort to bogus number such as this because they know that results from all of the current, valid studies go against them.
Lies, damned lies and statistics. Especially in the hands of politicians, and TV hosts who don’t like doing the leg work to check their facts.