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That’s the claim from the Brady Campaign to Prevent Gun Violence’s Tweet. Click on the image to embiggen [sic] or click here for the original.

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  1. The spike we would expect after the expiration of the Brady Bill didn’t materialize. In fact the rate of firearms related deaths seem to pace the population growth.

    If anything, the graph proves that the Brady Bill has a spurious relationship with the decline of firearms related deaths. The modern rate of firearms related deaths is still lower than before the Brady Bill was passed.

    This graph says the Brady Bill had no effect.

    • Absolutely correct. The normalized figures (which are the correct ones to look at in this case) say that gun violence is either holding steady or on the decline.

      But there’s this bright red line at the top of the graph. A line that goes down when gun control is enacted, and up when it’s removed. Which line do you think most people will see, the bright red one at the top or the grey / black ones jumbled at the bottom?

  2. This is a worthless graphic. Correlation does not equal causality. There are dozens of unaccounted for variables here.

  3. For those interested in the actual data and information that were used to generate the above graph, the full explanation and Excel spreadsheet is available here:

    In short, the graphic was intended to disprove the belief that “more guns = more deaths”, and the associated Pearson Correlation Coefficient analysis handily shoots that myth down.

    Likewise, this graphic disproves the “more guns = more gun crime” myth:

    As both posts indicate, you are free to use any of those graphics wherever you like, so long as they remain unedited and your use includes a link back to the original posts.

  4. Regardless of subject, this is so irresponsible with regard to statistical analysis I’m practically jumping through my own sphincter just thinking about it.


    • I am an expert in statistical analysis, and trend arguments such as this one are misleading and irresponsible regardless of topic. I’d say the same just as readily if it was a “pro” gun argument being made in this fashion.


        • You do realize that Don’s comment is exactly my point, Mike, right? And that the Brady Bunch, being the incorrigible idiots they are, made complete asses of themselves with their misappropriation of that graphic? To wit, they are taking credit for something they cannot prove they are responsible for, and they are blaming something they cannot prove is itself responsible.

        • You’re welcome, though it shouldn’t take 12 years experience working in applied mathematics to recognize an invalid statistical argument regardless of topic. What is covered in a properly administered high school stat class should be enough grounds to reject false statistical arguments or confirm valid ones.

          We must promote math and science education in schools. Growing a new population of adults with fundamental capabilities for critical thinking, problem analysis, and solution synthesis is really the only solution to the world’s problems.

          Policy and programs based on accurate modeling and interpretation of world phenomenon are both efficient and effective. Sound fundamental ideals implemented through poor policy and programs are as useless and as wasteful as implementing bad fundamental ideas.


  5. Early in the 20th century, doctors suspected ice cream and swimming pools of being carriers of the polio virus, because many children were infected each summer. We now know better, but it goes to show that correlation does not equal causality. There are so many more variables to account for. One could also say that prior to the passing of an anti-gun law, gun sales skyrocket, and due to the increased number of legally owned guns, criminals tend to back off.

  6. To me, the graph suggests that the Brady Act’s five day waiting period was effective at reducing the number of US gun deaths, since gun deaths dropped while the Act was in full effect and have been constant since the waiting period was ended. Clearly, something different was happening with guns in the US from 1993 to 1999, and the Brady Act’s waiting period is my best guess.

    Nguyen and Leghorn say they’d expect a spike after the expiration of Brady, but that’s bad logic. It would require something like a huge gun buyback to cause an instant step-like drop in the number of gun deaths. The Brady Act didn’t do a gun buyback, of course. With Brady, sales were constricted a little (Brady blocked less than 1% of gun sales, mostly to felons) so you wouldn’t expect a step-down in gun deaths, but rather a reduction in the SLOPE of the gun-death-count (red) or gun-death-rate (black) curves, and that’s exactly what we see.

    Linoge (Jonathan Sullivan?) argues elsewhere that correlation coefficients tell you the graph disproves that more gun means more deaths, but that is horrible statistical reasoning, as Don points out. There are lots of other variables here beyond the number of guns: changes in demographics, crime, gun hardware, economy, and gun laws between 1981 and 2007.

    Farago doesn’t say what he considers incendiary about the graph. He gives no link to the Brady tweet, and his link to the wallsofthecity web site is broken.


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