A calculus for causality?

Mind blowing ideas on probability theory (perhaps new only to me). A quote on the ideas applied:

Should we, in salary discrimination cases, compare salaries of equally qualified men and women, or, instead, compare qualifications of equally paid men and women? Remarkably, the two choices led to opposite conclusions. It turned out that men earned a higher salary than equally qualified women, and SIMULTANEOUSLY, men were more qualified than equally paid women.