Forecasting Track Records

Paul Krugman:

Who You Gonna Believe?: I went through my mail today, and got the usual batch of letters declaring that I’m wrong about everything, and that we should do the opposite of anything I say. Hey, it’s a free country. But I found myself wondering, as I often do, about the determination with which people believe pundits who please them ideologically, no matter how wrong they have repeatedly been — wrong in ways that, if you believed them, cost you money.

Suppose you had spent...