The New York Times Magazine has released its annual "Year in Ideas" package--alphabetically analyzing such interesting new developments as man-made greenery and bicycle highways.

In the "Os" there is, of course, our current president, Barack Obama. The entry related to him, however, explores a trend that's become known in social science circles as "stereotype threat"--lower performance among blacks due to the perception that they are beneficiaries of racial preference. Certain scientists believe this contributes to the achievement gap between blacks and whites, as well as other minority groups like women or the elderly. In November 2008, the "threat" became larger than life for blacks in America--as the first African American president and his family took up ressidence at the seat of global power.

So how to quantify the so-called "Obama effect?"

At a series of moments during the 2008 campaign, Marx and his colleagues gave tests of verbal ability to selected black and white students after first priming them to focus on racial stereotypes of academic performance.

In a paper published this year in The Journal of Experimental Social Psychology, Marx and his colleagues reported that there was indeed an Obama effect, though it had certain limitations. Right after Obama's speech in Denver accepting the Democratic nomination, for instance, the negative effect of stereotype threat was significantly reduced for black students — but for only those who had actually watched the speech. Right after the election, black students again scored better, but at another point in the campaign, there was no measurable effect on their scores.

I can't give too much weight to this theory, which reads like a triple-bank-shot analysis: Black students who think that others think that someone else has given them a leg up because of race can't hack it on a test? I haven't seen the data, but it seems a reach, at best. One dissenting researcher cited by the Times had it right: "I suspect that the greatest contribution Obama will make to narrowing the achievement gap will be his policies, not his persona."

One achievement gap in the Times coverage that does seem worth pondering: that between black and white quarterbacks in the National Football League. There is a significant body of evidence suggesting an unfair pay grade that disadvantages black players like Donovan McNabb and the late Steve McNair:

The key is that owners do not fairly compensate quarterbacks who are good at running the ball in addition to throwing it. Using 35 years of data, Berri and Simmons found that while white quarterbacks, on average, run with the ball on only 6.7 percent of their plays, gaining a measly 7.3 yards per game, black quarterbacks run, on average, 11.3 percent of the time and gain 19.4 rushing yards per contest. In other words, many black quarterbacks tend to be good runners as well as good passers. And quarterbacks are not paid for the rushing yards they produce.

An outrage! As with the earlier example of disparate performance, the structure (political or otherwise) contributing to this outcome seems the key to any explanation or resolution. I'm no NFL statistician, but why can't the quarterback rating be changed to reflect what is clearly value added on the field?