The 4 boneheaded biases of stupid voters: (And we're all stupid voters.).

• Author: Caplan, Bryan
• Position: Cover story

ALMOST ALL the "respectable" economic theories of politics begin by assuming that the typical citizen understands economics and votes accordingly at least on average. By a "miracle of aggregation," random errors are supposed to balance themselves out. But this works only if voters' errors are random, not systematic.

The evidence--most notably, the results of 1996 Survey of Americans, and Economists on the Economy--shows that the general public's views on economics not only are different from those of professional economists but are less accurate, and in predictable ways. The public really does generally hold, for starters, that prices are not governed by supply and demand, that protectionism helps the economy, that saving labor is a bad idea, and that living standards are falling. Economics journals regularly reject theoretical papers that explicitly recognize these biases. In a well-known piece in the Journal of Political Economy in 1995, the economists Stephen Coate and Stephen Morris worry that some of their colleagues are smuggling in the "unreasonable assumptions" that voters "have biased beliefs about the effects of policies" and "could be persistently fooled." That's the economist's standard view of systematic voter bias: that it doesn't exist.

Or at least, that's what economists say as researchers. As teachers, curiously, most economists adopt a different approach. When the latest batch of freshmen shows up for Econ 1, textbook authors and instructors still try to separate students from their prejudices. In the words of the famed economist Paul Krugman, they try "to vaccinate the minds of our undergraduates against the misconceptions that are so predominant in educated discussion."

Out of all the complaints that economists lodge against laymen, four families of beliefs stand out: the anti-market bias, the anti-foreign bias, the make-work bias, and the pessimistic bias.

Anti-Market Bias

I first learned about farm price supports in the produce section of the grocery store. I was in kindergarten. My mother explained that price supports seemed to make fruits and vegetables more expensive but assured me that this conclusion was simplistic. If the supports went away, so many farms would go out of business that prices would soon be higher than ever. I accepted what she told me and felt a lingering sense that price competition is bad for buyer and seller alike.

This was one of my first memorable encounters with anti-market bias, a tendency to underestimate the economic benefits of the market mechanism. The public has severe doubts about how much it can count on profit-seeking business to produce socially beneficial outcomes. People focus on the motives of business and neglect the discipline imposed by competition. While economists admit that profit maximization plus market imperfections can yield bad results, noneconomists tend to view successful greed as socially harmful per se.

Joseph Schumpeter, arguably the greatest historian of economic thought, matter-of-factly spoke of "the ineradicable prejudice that every action intended to serve the profit interest must be anti-social by this fact alone." Anti-market bias, he implied, is not a temporary, culturally specific aberration. It is a deeply rooted pattern of human thinking that has frustrated economists for generations.

There are too many variations on anti-market bias to list them all. Probably the most common error of this sort is to equate market payments with transfers, ignoring their incentive properties. (A transfer, in economic jargon, is a no-strings-attached movement of wealth from one person to another.) All that matters, then, is how much you empathize with the transfer's recipient compared to the transfer's provider. People tend, for example, to see profits as a gift to the rich. So unless you perversely pity the rich more than the poor, limiting profits seems like common sense.

Yet profits are not a handout but a quid pro quo: If you want to get rich, you have to do something people will pay for. Profits give incentives to reduce production costs, move resources from less-valued to more-valued industries, and dream up new products. This is the central lesson of The Wealth of Nations: The "invisible hand" quietly persuades selfish businessmen to serve the public good. For modern economists, these are truisms, yet teachers of economics keep quoting and requoting this passage. Why? Because Adam Smith's thesis was counterintuitive to his contemporaries, and it remains counterintuitive today.

A prejudice similar to the one against profit has dogged interest, from ancient Athens to modern Islamabad. Like profit, interest is not a gift but a quid pro quo: The lender earns interest in exchange for delaying his consumption. A government that successfully stamped out interest payments would be no friend to those in need of credit, since that policy would crush lending as well.

Anti-market biases lead people to misunderstand and reject even policies they should, given their preferences for end results, support. For example, the Princeton economist Man Blinder blames opposition to tradable pollution permits on anti-market bias. Why let people "pay to pollute," when we can force them to cease and desist?

The textbook answer is that tradable permits get you more pollution abatement for the same cost. The firms able to cut their emissions cheaply do so, selling their excess pollution quotas to less flexible polluters. End result: more abatement bang for your buck. But noneconomists, including relatively sophisticated policy insiders, disagree. In his 1987 book Hard Heads, Soft Hearts, Blinder discusses a fascinating survey of 63 environmentalists, congressional staffers, and industry lobbyists. Not one could explain economists' standard rationale for tradable permits.

The second most prominent avatar of anti-market bias is monopoly theories of price. Economists acknowledge that monopolies exist. But the public habitually makes monopoly a scapegoat for scarcity. The idea that supply and demand usually...