Scott Sumner points out that Paul Krugman’s latest column makes a basic logical error. Krugman notes a study that finds that stimulus spending leads to more jobs where the money is spent, but then makes the logical leap to the proposition that it leads to more jobs overall. Since stimulus spending is highly uneven (indeed, it is allocated exclusively by political considerations), the one hardly implies the other.
Honest mistake? Well, Krugman is a smart guy, but somehow that hasn’t stopped him from a history of mistakes; mistakes that a smart guy like him should be incapable of. His notorious divide-by-ten error comes to mind. At the time he tried to defend himself:
No, I didn’t forget to divide by 10. (For God’s sake: whatever you think of my politics, I am a competent economist, and know how to use numbers.)
Indeed, Mr. Krugman. That’s one reason we don’t think it was an accident.