Wednesday, April 13, 2011

Quantiative Reasoning Fail

Most of my research involves examining and reasoning about data. I'd say that in the course of my education as a linguist, I have developed some pretty ok quantitative and statistical reasoning skills. What's so great about having these reasoning skills is that they are very broadly applicable.

Occasionally, I'll observe, or hear second hand, someone with no quantitative reasoning skills discussing a topic that calls for them, and more often than not I'm blown away by the simple errors they make that lead to large confusions. For example, there was the time that George Will claimed that Obama is narcissistic because he used first person pronouns at a high rate.
"I," said the president, who is inordinately fond of the first-person singular pronoun, "want to disabuse people of this notion that somehow we enjoy meddling in the private sector."
Of course, George Will didn't exactly count how often Obama used the first person pronoun. And crucially, he didn't compare Obama's usage to any other president. Mark Liberman, calling himself "one of those narrow-minded fundamentalists who believe that statements can be true or false" counted and compared, and found that Obama's usage rate of first person pronouns was actually less than the previous two presidents, not that it even really means anything.

President% of words which are first person pronouns
Bush II4.49%

More recently, you have Senator Jon Kyl stating on the Senate floor that over 90% of what Planned Parenthood does is abortions. Of course, when fact checked, it turned out that about what 3% of what planned parenthood does is abortions. Kyl's defense? "It was never intended as a factual statement." I think the Daily Show coverage says it best.

Now, in the next bit the Daily Show did, they called what Senator Kyl did "lying." I have a different take. Worse than lying, I think Senator Kyl has no notion that numbers mean anything. That "90%" is just an emphasis marker, like "so," or "extremely". Of course, this can't strictly be true, because there are some pretty important percentages that determine whether or not he keeps his job, and surely he attends to those.

The question remains, how can Jon Kyl or George Will think they can just say things without any regard to the actual facts of the world? I think the problem is not just isolated to these individuals, and the consequences are potentially severe.

Take the debate that was raging before the passage of healthcare reform. One topic that really caught my eye was rescission, which is when heath insurance companies drop individual's coverage. Insurance Company representatives testified that rescission is very rare, only effecting one half of one percent of customers.

And no one called them out on the uselessness of that number! 0.5% of all insurance customers is entirely uninformative! What really matters is what percent of people who file claims are dropped. And even then, what really matters is how often people who have really severe, and expensive illnesses get dropped. This blog post estimated that it was close to 50% of people who file large claims get their health insurance dropped.

And that's not rocket science! Yet, no one called these representatives out on the (probably intentional) uselessness of their data! I remember thinking to myself "What's wrong with all of you!?"

Here's what it comes down to. As I see it, if you don't understand data, then you don't understand the world, and you will make bad decisions, and be taken advantage of.

In conclusion, I think it would be a great idea to overhaul high school mathematics to make statistics the end game, instead of calculus, as proposed by Arthur Benjamin in this TED talk.


  1. Totally agree that stats should replace calculus

  2. I’ve long thought that nobody in America should ever be allowed to call themselves a “journalist” if they haven’t taken a year of university-level statistics.


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