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May 19, 2012 12:49 PM Innumeracy Among Political Journalists

By Andrew Gelman

John Sides shoots down David Brooks’s claim that “If you look at the fundamentals, the president should be getting crushed right now.” John points out (as does Ezra Klein) that if you look at the fundamentals, you’d expect a close election. OK, there are lots of ways of looking at politics, elections, and the economy, and I’m sure that some forecasts give Obama a bit lead. But that’s hardly a consensus reading of the fundamentals. The more parsimonious reading here is that Brooks was (a) misinformed and (b) didn’t know with whom to talk to get informed.

I’m reminded of the statements last December from Gregg Easterbrook that (a) if Newt Gingrich were to become the Republican nominee, he’d have a 10% chance of beating Obama, and (b) “If I am Barack Obama, I want to run against Mitt Romney.”

Easterbrook didn’t seem to realize that if you put these two pieces together, you get the claim that Romney has less than a 10% chance of winning. (Intrade currently has Romney at 40%. At the time of Easterbrook’s post, Intrade had Romney with a 33% chance of being elected president in 2012, unconditional on the results of the Republican nomination.)

I have no objection to Brooks arguing that the political science models are wrong, just as there’s nothing wrong with Easterbrook arguing that the punters on Intrade are deluded. But I’d like to see them make the actual argument, to confront the implications of what they’re saying.

One aspect of innumeracy is seeing numbers as words, as rhetorical expressions rather than as quantities that can be added and subtracted, multiplied and divided. That’s what’s going on when Brooks talks about the fundamentals without looking, when Easterbrook throws out a bunch of predictions without checking their coherence, or when Reid Hastie thinks there’s a there’s a 20% chance “that a massive flood will occur sometime in the next year and drown more than 1,000 Americans.”

Also, deadline pressure. These guys don’t get to blog whenever they want, like we do. And they’re not rewarded for making sense, they’re rewarded for getting attention. Maybe even this sort of attention is ok for them.

[Cross-posted at The Monkey Cage]

Andrew Gelman is a professor of statistics and political science and director of the Applied Statistics Center at Columbia University.
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