Paul Krugman asks why more economists didn't make more of an effort to draw attention to the bubbles in the US housing market. My answer is that economists are by training - if not by nature - perhaps too diffident. If people behave in a way that cannot be reconciled with what our theories predict, our instinct is to presume that our models are wrong.
This training starts early. I used to teach a course in which I would ask students to choose between the lotteries of the Allais Paradox, and then explain how only certain combinations of preferences could be consistent with the expected utility hypothesis. I would then go on to point out that the fact that a significant number of students made 'wrong' choices should be interpreted as a weakness of the theory, and not as evidence of the inability of certain students to think straight.
For example, I've not been able to make head nor tail of stock market data since 1995. But my reaction has been to shrug, and wonder where my thinking had gone wrong. It quite literally never occurred to me to write a series of op-eds warning of impending doom.
I wonder to what extent the world would be a better place if economists were as arrogant as non-economists claim they are.