Earlier quoted context omitted.
I'm sure there are plenty of ways for this to backfire, but I've always thought one of the most effective ways to eliminate salary bias is for companies to list a role's salary up front, in the job posting, before they've begun interviewing. That way the salary is roughly set before the gender, race, height, physical attractiveness (i.e. any qualities that can cause unconscious bias) is known about whatever candidate…
IMHO, managers like to keep salaries private so that they can take advantage of people who are not great at negotiating. My suspicion is that they believe they come out ahead: the few hires who negotiate high pay are outweighed by the many who end up with lower pay. I'd also be surprised if many of them were concerned that minorities or women ending up with lower pay; it seems like a great opportunity to blame these…
Publicising that a new unproven hire is earning more than existing proven staff is simply going to cause people to leave, which is even worse for the business than not hiring new staff.