Randall Parker points to this article.

[Erik] Angner, an assistant professor of philosophy at the University of Alabama at Birmingham (UAB), published a paper, “Economists as Experts: Overconfidence in Theory and Practice,” in a recent edition of the Journal of Economic Methodology in which he says there are reasons to think that overconfidence is endemic among economists who are called upon by public policy makers for their expertise. And economists’ overconfidence, said Angner, can have dramatic effects on both public policy and investors.

…To support his thesis that economists are likely to be victims of overconfidence, Angner’s article points to a number of empirical studies on the psychology of judgment and decision-making. Many of those studies have documented evidence of overconfidence among those called upon to make expert judgments, including economists, doctors, physicists and even CIA analysts.

I confidently predict that further research will show that economists are subject to confirmatory bias. That is, we give credence to findings that can be construed as supporting our point of view, while being skeptical of findings that contradict our point of view. Thus, I give credence to Angner’s findings.

I also think that there is selection bias going on in the news media. Reporters, like Harry Truman, are looking for a one-handed economist.