Happy Equal Pay Day! Women still earn less than men

It's a day ending in Y, which means if you glance around, you'll find yet another piece of evidence showing the persistence of the gender wage gap, and Tuesday is Equal Pay Day, which means there's an actual study on pay disparities. The Institute for Women's Policy Research has released an analysis showing that:

[W]omen have lower median earnings than men in all but one of the 20 most common occupations for women, 'bookkeeping and auditing clerks,' where women and men have the same median earnings. In one of the twenty most common male occupations, 'stock clerks and order fillers,' women out-earned men by 3 percent of median male earnings.

Occupations dominated by men pay more, and then within occupations, men are paid more. But wait'it's a day ending in Y, which means that comment threads everywhere on the internet will be inundated with men mansplaining about how women just care less about money, or how various unexplained factors that are definitely not sexism account for any and every piece of evidence that no matter what factors you control for, the gender gap persists. Because sexism is not a science, or even a keen analysis. It's a belief system.