Note that tiny fractional differences in the median outcome gap will turn into big differences at the left- and right-wards tails of the distribution. In practice, those are the differences that everyone will ask about. Why are so many X's (relative to Y's) living in socially marginalized settings, resorting to crime, ending up in the justice system? Why are there so very few X's in very high-skill, high-effort occupations like computer programming and other hard-STEM fields? The X's and Y's will vary by time and place, of course. And societal oppression of various sorts is always playing a role in these dynamics, if only as an amplifying feedback. But either way, these are questions about uncommon, tail outcomes not average or median ones!