Just wanted to bump in on this particular part: It is an absolutely bonkers claim I've heard a million times and it all stems from an article in the Wall Street Journal and The Washington post based off of a lazy interpretation by a professor (Goldin, at Harvard) and then semi-rehashed by Forbes, CBS Money, Fortune etc. It is interpreted by people with a bias who don't understand the topic very well at all (on top of the fact that you can't prove something is nonexistant unless you prove that it does not exist in every possible case which no one is even close to doing in the first place).
Prof. Goldin has explained that the 77-80% number is what you say, a poor number to use. That is all. She clearly says there is a gender gap, she explains her theories of why, she even says that there is partly an actual wage gap in hourly pay for the exact same job by the same qualifications, just that it does not ofc. result in the 77-80% difference, rather that social factors do, which does not in any way mean there is no wage gap, something everyone who rehash it assumes.
Her studies have been used to argue for the exact opposite as well, by herself (Goldin). I just lazily googled three examples:
From the NY times where Goldin apparently argues strongly that there is a gender wage gap:
Harvard magazine and Goldin apparently argues that there is no gender wage gap:
and here is a something inbetween article by the Business Insider:
Funny how they all talk to the same person and get different interpretations? And on top of that there are a bunch of cases where there is exactly that, women on average get less than men, per hour, for the exact same job description and plenty of real published studies have shown it if you care to google, something even the Washington post article concedes, using a 5% difference (from somewhere) instead, as if that makes it ok.
Not to mention that there are droves of economists who argue that there is a wage gap for a bunch of reasons, yet a surprisingly large portion of arguments for why there isn't stem from these interpretations of Goldin's studies.
I am in a field where proof is not easily tossed around and this is not by any means disproven in the slightest, not by any proper method of proof theory anyway, so I had to butt in, and to clarify: it is not a dig at you, it is more about killing the misconception that it is all a myth
I googled interviews with her, found one here where she talks a lot, anyone who wants to can read some of her own words, arguments, findings and theories, all in context, it is a radio interview published in a mag, in text (long read):