Economists as Experts (Repost I)

Economists have a chip on their shoulder, or at least I do. Nobody argues gravity with a physicist, or covalent bonding with a chemist, but they do argue supply and demand with an economist. Nobody ever asks if a physicist or a chemist is biased, but people make these claims all the time about economists. Like Rodney Dangerfield, economists, "don't get no respect."

In his book, The Myth of the Rational Voter: Why Democracies Choose Bad Policies, Bryan Caplan describes two common biases that many think economists possess. They are self-serving bias and ideological bias.

Self-serving bias is based on a literature that suggests that people form beliefs that are comfortable and support their financial interests. As an expression of self-serving bias, Lincoln said of slaveholder,

The effect on the minds of the owners is to persuade them that there is no wrong in it. The slaveholder does not like to be considered a mean fellow, for holding that species of property, and hence he has to struggle within himself and sets about arguing himself into the belief that Slavery is right. The property influences his mind. [1]

The argument implies that economists are on average well-to-do, and have job security and therefore support policies that help the rich through markets. Caplan's statistical analysis suggests that self-serving bias does not explain economists' views. If economists had the same level of income and job security as the average person, their opinion on policy would still mirror those of other economists.

Ideological bias suggests that economists beliefs were shaped by their free market mentors. If Republicans are more conservative than Democrats, implying that they are more likely to support free market policies, the accusation does not fit. Economists are more likely to be Democrats than Republicans. Daniel Klein and Charlotta Stern (How Politically Diverse Are the Social Sciences and Humanities? Survey Evidence from Six Fields) surveyed six social science disciplines. The overall response rate of 30.9% and the small number of academic economists responding (96) suggests that results should be interpreted with caution. Academic economists were defined as those working at four year colleges or above. They found that three times as many economists vote regularly for Democrats as compared to Republicans.

The Economist.com (Examining the candidates) surveyed 683 research economists at the National Bureau of Economic Research, and found similar results to Klein and Stern.

A total of 142 responded, of whom 46% identified themselves as Democrats, 10% as Republicans and 44% as neither. This skewed party breakdown may reflect academia’s Democratic tilt, or possibly Democrats’ greater propensity to respond. Still, even if we exclude respondents with a party identification, Mr Obama retains a strong edge—though the McCain campaign should be buoyed by the fact that 530 economists have signed a statement endorsing his plans.

Their nonscientific results find that Democrats outnumber Republicans 4.6 to 1, an even stronger result.

Caplan compares the political beliefs and policy views of 250 Ph.D. economists and concludes,

Compared to the general public, the typical economist is left of center. Furthermore, contrary to critics of the economics profession, economists do not reliably hold right-wing positions. They accept a mix of 'far right' and 'far left' views.

Economists may have biases, but they are not self-serving bias or ideological bias as often claimed.

[1] Miller, William Lee. Lincoln's Virtues: An Ethical Biography, Alfred A. Knopf, New York , 2002, page 388.