The WaPo has a decent article on the false claim that there is a gender wage gap. They do a good job showing how various mis-measures (more accurately: mis-comparisons) of wages lead to both very different measures of wage gaps and very large wage gaps. These mis-measures are used for all sorts of nefarious political purposes.
Here is the key thing to note:
“But, under this metric for people with a college degree, there is virtually no pay gap at all.
This brings us to our larger point: Broad comparisons are inherently problematic. As the BLS points out: “Users should note that the comparisons of earnings in this report are on a broad level and do not control for many factors that may be significant in explaining earnings differences.”
The reason that there is no pay gap is that pay gaps are market inefficiencies that naturally correct. Any business not willing to pay top dollar for top talent is at a competitive disadvantage to other businesses that do pay. Eventually – maybe not in the near term, and maybe not in some geographic regions, but in general everywhere in every time – pay gaps evaporate because businesses that would perpetuate them evaporate out of business.
Where you find real gaps are where there are real differences amongst workers along measurable metrics. For example: risk of the job and commitment to the job (which, yes, absolutely includes the possibility that certain people might want or have to take time off to deal with things like babies).