It used to be the case until the 1980's, whereupon there was a deliberate shift away from quantifying the value of a role and towards quantifying the value of a

It used to be the case until the 1980's, whereupon there was a deliberate shift away from quantifying the value of a role and towards quantifying the value of a candidate. Somewhat counterintuitively, this was a deliberate measure to reduce exposure to discrimination lawsuits. The reasoning was that you could always argue that candidates were unequal in their experience/competence/etc., hence the observed wage differences within a single role. To be clear, there are upsides to this arrangement as well, namely: the ability to negotiate one's salary.