I'm working at a business with low pay--where the average for a programmer is $96k here, programmers make $74k. The same is true of most IT staff, running a good 20%-30% short of the industry median.
We're also fairly diversified and have chicks and people from all over the world in our staff, and have had folks who speak Russian or obscure Indian dialects as a primary language in prominent technical positions. They're also poorly-paid, although near as I can tell we all have about the same salary.
It seems like a form of posturing: we don't want to pay salaries, so we create a perception of
Are these studies by industry, region, experience, and business? Do we say that black women earn 55% as much as white men, or do we say that black women at business X in job Y earn 55% as much as white men in business X at job Y? What happens if business X mostly hires white men for job Y, and business X' hires a higher proportion of black and asian women for job Y but also pays like shit even if you're a white man?
That doesn't work. Recruiters will successfully poach someone getting underpaid or unhappy. So, it seems like you're unhappy about getting underpaid.
Competition is why people earn what they earn what they earn. Your employer cannot get away with paying you $x when employer B will pay you $(x+y). At a statistical level, maybe race and gender matters but on a personal level there are too many variations.