Yes, there's a whole book about this, Women Don't Ask: The High Cost of Avoiding Negotiation.

https://www.amazon.com/Women-Dont-Ask-Negotiation-Strategies...

> Yet, as research reveals, men are four times more likely to ask for higher pay than are women with the same qualifications. From career promotions to help with child care, studies show time and again that women don’t ask–and frequently don’t even realize that they can.

I'm a little surprised that there is a serious concern that this article doesn't address with gender-gapped salaries, though, and it's been touched upon several times on HN. Women tend to negotiate starting salaries and raises much less than men do, to the point where it can skew wage statistics by a nontrivial amount.

There was someone on HN a while ago who hired several engineers, and said that his company pays women less than men because he makes the same starting offer to several people, and almost all the men asked for more money, yet none of the women did. So the offers the company made were "fair", but the end results were very skewed wages.

There are entire books about this subject, such as "Women Don't Ask: The High Cost of Avoiding Negotiation"[1]

Companies could fix this overnight by disallowing negotiation (Didn't Fog Creek do this?), or making all employees salaries transparent (countries like Norway do this, and we do this for C-levels often in the US, just not plain old employees).

I suspect nothing institutional will change though because it would ultimately cost companies money. They benefit too much from workers who negotiate poorly.

[1] http://www.amazon.com/dp/0553383876