A little late on this thread, but did want to add - I'm not assuming that's what's happening here, but I know this has been overlooked in similar analyses. I think Google's hr team is probably smart enough to account for things like this, but I would really like for the report to say what other variables they controlled for in order to conclude that women are overpaid.

And I think someplace like Hacker news is exactly the right place for the community to discuss the many ways a company can get to a result like this - via Simpson's paradox, via differences in promotion velocity, or via simple economics, based on the fact diverse teams are desirable and women are more scarce.

Attacking someone for suggesting one not-yet-discussed possibility is not helpful to the discussion, imo.