Megan McArdle sees someone suggest that Bush’s tax cuts for the rich should be eliminated and the money used for better purposes, and she decides that it just wouldn’t make any difference. McArdle’s problems with the argument:
Dylan Matthews at the Washington Post has asked what we might be able to do for the economy if we repealed the Bush tax cuts for the wealthy and spent the money on something else. The result is a nice post full of graphs, but the answer seems to be “not much”–the very best estimate is that we get about $75 billion in added economic activity, or about $25 for every person in the country.
The first two commenters correct her math. “Or $250, whatever,” says the first. The second: “Using current census data, I get $244 per person, but yes let’s call it $250, Megan was off by a factor of 10.” McArdle and math are two ships that pass in the night, never to have contact. Fortunately her commenters are available to do her long division for her.
It’s not a small error — no one would argue that a $25 rebate check (say) per American would help the economy much, but it might be argued that a $250 one would (I have no idea if it really would, but that would be about the same size as the 2008 tax rebate). We all make mistakes, but if you make an order-of-magnitude error that potentially affects your argument, shouldn’t you make a correction and revisit the argument, using the time-honored method of the strike-bar and the update?
This burns me up, whether it’s David Brooks (failed math in high school, no evidence he’s improved) wanking about some graphs he saw on iSteve or claiming that Clinton had an approval rating “in the 20s”, Emily Yoffe critiquing global warming research from a first-grade math level, or McMegan not admitting that $25 and $250 are not the same number, I wish that truly innumerate people would shut the fuck up about everything related to quantitative analysis.
Update. In her very next post:
And we would all of us–not just academics–like to be immune from getting fired for making stupid remarks.
Update. Finally a correction, it’s because the calculator on her computer “won’t go into the billions”. In fairness, I just tested out the calculator on my Mac and if I try to enter 75 billion, it just stops at 750 million.
Anyway, as I said, everyone makes mistakes. I guess maybe it would have been a good idea to notice that the first few commenters pointed out the error rather than just screaming at them and calling them idiots.