Friday, December 28, 2012

Deceptive charting: stop it with the firearm death category

On Slate this morning there was a headline about how firearm deaths have surpassed motor vehicle deaths in 10 states.  The article cited a report by the Violence Policy Center that showed that between 1999 and 2010 there was a  decrease in motor vehicle deaths nationwide, and a slight increase in firearm related deaths.  Thus, the report and article argued, we are heading towards a day when firearm deaths surpass motor vehicle deaths.

I've blogged before about how deceptive I think the term "firearm deaths" is (as it lumps in police action, homicides and suicides as one group), and it turns out this is the same report that annoyed me the first time.  This time however, I was struck by the chart they included in the article:

I was curious about this chart....what would it look like if the firearm deaths were broken out in to categories? The VPC report said it used WISQARS to generate the data, so I took a look.  WISQARS actually has 5 categories for death by firearm:  homicide, suicide, unintentional, legal intervention and undetermined intent.  

Here's what those look liked graphed out:

Essentially, homicides by gun have not changed in the 11 year period covered here, though they did tick up in the middle.  Suicides have gone up.  If you're curious what the other three categories look like when they're not all bunched up:

So unintentional fatalities are decreasing, and the other two categories appear to be fairly constant.

As a reference point, the population was 280 million in 1999, and was 309 million in 2010.

To be honest, I don't have a strong opinion about gun control, but I do hold data integrity at a premium.  If we're going to talk about regulating guns in order to keep people safe, you have to either include suicide prevention as one of your foremost points, or you have to start using the homicide data only.  I do not believe it is intellectually honest to quote total firearm death statistics when the national conversation is clearly focusing on homicides.

If we don't start with the right data, how will we know if any interventions actually work?


  1. I don't think whether the interventions work is much the point. I think it's culture war. Gun laws have little effect, up or down, on the death rate. It is about whose culture will reign.

    As well as I can parse it out, tighter controls may help a little in urban areas, where police response times are faster, and impulsivity may be more of a risk. Tighter controls seem to make things worse in rural areas, where the opposite is true. But even at that, neither effect is large.

    I recall there was also some fuss about the numbers a decade ago because 16-18 y/o gang members were being counted at "children," and were 85% of the total for that group.

    1. *grumble grumble*

      I know what they're trying to do but I'm going to keep bringing up the "will this work" thing until they answer me.

      *grumble grumble*

  2. Doesn't that chart imply that deaths-in-automotives are decreasing?

    It's kind of dishonest to say "deaths-by-firearm have surpassed deaths-in-automobiles" when the data indicates "deaths-in-automobiles have dropped below of deaths-by-firearm".

    Which number changed the most, after all?

    Should the headline be about the advance of safety technology in cars, rather than the rate of deaths by firearm?

    The actual headline refers to 10 States, and the chart you show looks like a national rate. I'm assuming that the national trend has similar shape in most States.

    1. Yes, I didn't touch on it but they put an explanation in the article....essentially that regulation got us lower driving fatalities, so therefore the drop is proof that regulations would work for firearms.

      And I think you are correct that the difference between the words "surpass" and "dropped below" are key here.

      I'm actually kinda curious what happened around 2006 that made such a difference. I may have to check that out.