David Colander writes,

not only are economists as a group not humble enough, what lay people are presented as economist’s policy recommendations are often the policy recommendations of the least humble economist. In summary, my argument is that lack of humility in conveying the limitations of their results is the most serious ethical problem facing economists; it played a much larger role in causing the recent financial crisis than did the type of payments highlighted by Inside Job. Thus, and any new code of ethics for economists should deal with that humility problem.

Pointer from Tyler Cowen. To say that I agree would be an understatement.

The article goes on to draw an analogy between economics and engineering, which I might quarrel with. The way I think of engineering, at some point the engineer knows whether the system or product works, in the sense of doing what is supposed to do. In economics, I doubt that we obtain comparably reliable knowledge about whether a policy or economic model works.