Friday, August 29, 2008

Positive bias and normative bias

The opposite of analysis is bad cliché, a sloppy knee-jerk. It's whenever an innocent-looking question in Econ 1 provokes a response that is answered with a phrase like "greedy companies"; it might even be whenever economics is confused with "business" or "finance", because, after all, what short-circuits economic analysis faster than pinning a label of bias on economists?

Not that you couldn't defend such a label. After all, it certainly looks like economists are biased when your first contact with them as a student of the subject is our friendly principles course. What a delicate balancing act, though. Bryan Caplan quotes Paul Krugman:

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."

Make no mistake, there's a reason why it's so difficult to play devil's advocate to argue against the very real work of introductory economics courses. Is there a fundamental difference between positive bias and normative bias? Normative bias is opinion, and represents healthy disagreement: "I believe the minimum wage should be raised, even if it raises unemployment, because those people who do work at minimum wage are impoverished", or "I believe the minimum wage should not be raised, even given that those who work at minimum wage are impoverished, because it might wreak havoc with the labor market". Both acceptable, both, arguably, representative of what you might call "normative bias".

Positive bias is more problematic. It could be accurately called "being wrong". That's the kind of problem that leads the designers of introductory economics courses to swing wildly to the extreme of trying to batter the bias out, looking suspiciously like indoctrination in the process. Think of how disheartening it is, though, to face a whole class who have heard about "competition" with Russia, China, India, whatever country is the current flavor of Evil, and try to teach the theory of comparative advantage. A very real challenge for economists is to explain the (deceptively simple) positive theories that form the foundation for the argument in favor of trade (personal and international), markets, government, etc etc, while walking the tightrope across the normative ravine.

The challenge, then: is a student who says "globalization hurts America" wrong? Is this a positive bias or a normative bias? More accurately: is this an opinion or a misreading of fact? What about a student who uses the sinking-feeling phrase "greedy oil companies" when asked to evaluate the effects of a gas tax? Here's a passage from that Bryan Caplan article:

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.

And again, on international trade:

How can anyone overlook trade’s remarkable benefits? Adam Smith, along with many 18th- and 19th-century economists, identifies the root error as misidentification of money and wealth: “A rich country, in the same manner as a rich man, is supposed to be a country abounding in money; and to heap up gold and silver in any country is supposed to be the best way to enrich it.” It follows that trade is zero sum, since the only way for a country to make its balance more favorable is to make another country’s balance less favorable.

Even in Smith’s day, however, his story was probably too clever by half. The root error behind 18th-century mercantilism was an unreasonable distrust of foreigners. Otherwise, why would people focus on money draining out of “the nation” but not “the region,” “the city,” “the village,” or “the family”? Anyone who consistently equated money with wealth would fear all outflows of precious metals. In practice, human beings then and now commit the balance of trade fallacy only when other countries enter the picture. No one loses sleep about the trade balance between California and Nevada, or me and iTunes. The fallacy is not treating all purchases as a cost but treating foreign purchases as a cost.

My own bias is to worry that we mistakenly strangle normative bias out of the economics classroom by too-much, too-soon overzealousness. Yet how else will we be able to impart the simple, counterintuitive lessons that will help us to fight positive bias?

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