And it’s not just the fact that you can choose your ideology, but not your race. Ideologies have a real effect on overall life outlook, which has a direct impact on job choices. Military officers are much more conservative than the population at large; so?
…
It’s particularly troubling to apply some test of equal representation when you’re looking at academics who do research on the very subjects that define the political divide. Biologists, physicists, and chemists are all predominantly liberal; does this reflect discrimination, or the tendency of people who actually know science to reject a political tendency that denies climate change and is broadly hostile to the theory of evolution?
From Krugman
On bias and head counts. Good point.