[nl]

Bob: Can you give me an example?

nl: Sure.

To overcome possible biases in hiring, most orchestras revised their audition policies in the 1970s and 1980s. A major change involved the use of blind' auditions with a screen' to conceal the identity of the candidate from the jury. Female musicians in the top five symphony orchestras in the United States were less than 5% of all players in 1970 but are 25% today. We ask whether women were more likely to be advanced and/or hired with the use of blind' auditions. Using data from actual auditions in an individual fixed-effects framework, we find that the screen increases by 50% the probability a woman will be advanced out of certain preliminary rounds.[1]

Bob: What? But that doesn't count because...

[1] http://gap.hks.harvard.edu/orchestrating-impartiality-impact...

[lexcorvus]

I didn't say there are no valid examples of bias, just that many people assume unequal outcomes must result from unequal opportunity, ignoring the possibility of real group differences. Surely you know many real-life Alans who see bias every time a particular Group X is underrepresented in Field Y. Moreover, the values of X aren't random; you'll almost never hear complaints of bias regarding, say, trash haulers, or NFL cornerbacks. (But NFL quarterbacks—ah, plenty of bias there!)

[mannykannot]

Speculative explanations - i.e. assumptions - are not uncommonly offered in support of the proposition that there is no underlying bias. Nl provides a rare example of the assumptions being systematically investigated.