I can’t explain why I’m writing this article. Too much caffeine? Maybe. Feeling intellectually insecure? Always. Or is it just that people as brilliant as Matt Yglesias should be spanked publicly when providing the smallest of justification? Yep! I think that’s the one.

Yglesias is one of my very favorite bloggers because he writes on a lot of different topics and I find him by turns insightful and oafish. I very often disagree with him but he usually makes a pretty good argument and never has uninteresting opinions. And sometimes, very rarely, he makes a math error that allows me to pounce! Ha ha ha!

I’ll bet Mr. Yglesias didn’t think twice when he wrote this earlier this morning:

This is so delicious that it is hard to even write about it. Yglesias first notes the error that Maker’s Mark made: they didn’t know the difference between percent and percentage points. The fools!

I’m sure you know people who are grammar pedants. They tell you that “irregardless” isn’t a word. (It is.) Or that it is wrong to start a sentence with a conjunction. (It isn’t.) Well, there are also math pedants. And they will correct you if you use “percent” when you meant “percentage point.” It really doesn’t matter, although in writing, I try to get it right.

Let me explain with the Maker’s Mark example. If they had reduced the alcohol content by 3%, that would have reduced it by 0.03*45% or 1.35%. Instead, they reduced it by 3 percentage points: from 45% down to 42%. Percentage points are simple: no multiplication!

But this raising a question: what the hell was Yglesias getting at when he said that 3 percentage points was “still a substantial change”? He is implying that a 3% change would have been more! So he just embarrassed himself publicly! Feel the shame, Matt?

Neener neener neener!