Suppose most economists believe that "Libertarian economists can't do math," and that, on average, they are correct. How does this affect libertarian economists' incentive to learn math?

You could say that this stereotype will be self-fulfilling. If everyone assumes that you can't do math, the marginal benefit of learning more math is zero, right?

Well, maybe that's right on a homework problem. But how about the real world? In the real world, there are ways of showing that you are counter-stereotypical. For example, a libertarian economist could write his dissertation on game theory under Avinash Dixit. Will people *still* assume that the libertarian economist can't do math? I think not.

In more general terms, even if people look down on the average member of your group, it's hardly clear that your *marginal* incentive to do better is worse than anyone else's. In fact, as my Dixit example illustrates, if people think your group is bad in some way, the marginal benefit of counter-stereotypical behavior is probably unusually BIG. The expected mathematical ability of a non-libertarian who writes under Dixit goes from very good to excellent. The expected mathematical ability of a libertarian who writes under Dixit goes from poor to excellent. These look like incentives for a self-*reversing* prophesy to me.

If I'm right, though, shouldn't all statistical discrimination undo itself? Sure, if groups were really the same to begin with. But they're not. Libertarians go into economics to think big thoughts, not solve equations. It would be amazing if their average mathematical ability could equal that of people who go into economics *because *they like solving equations. The result: Even though libertarians have a stronger incentive to learn math, they are still less proficient.

Overall, it seems like my example generalizes. If taxis are reluctant to pick up young, black males, then young, black males probably have an unusually *large* marginal benefit of wearing a suit. Outside of a simple-minded homework problem, statistical discrimination is a reason to try harder, not a reason to give up.

P.S. This post was partly inspired by a David Balan post on Overcoming Bias.

Right, down through history you can see lots of examples of "stereotype stimulation" in contrast to the widely celebrated concept of "stereotype threat," which assumes that when taking tests, blacks collapse under pressure. That would seem racially derogatory. Back in the bad old days, it was bigoted whites who jeered that black sports pioneers like Joe Louis, Jesse Owens, and Jackie Robinson would choke as soon as the spotlight was on them. They didn't. Similarly, Paul Robeson didn't suddenly forget his lines when the curtain came up on Othello, nor did Marian Anderson sing off-key at the Lincoln Memorial. In fact, they all seemed to experience the opposite of stereotype threat: "stereotype stimulation," a burning desire to prove their naysayers wrong.

When you talk about non-libertarian economists, to whom do you refer? Are you referring to the sort of economist that throughout much of the 20th century thought the USSR was doing great and was going to overtake the US? Who said things like, "the Soviet economy is proof that, contrary to what many skeptics had earlier believed, a socialist command economy can function and even thrive"?

On a completely unrelated point, I hear Paul Samuelson was very mathematically literate.