Interestingly, the NYT had an article that referred to a study about the prevalence of women in computer science in the 60s and early 70s vs. now.   There were a lot more back then.    The point was made as part of a study that showed that as compensation in a field rises, the percentage of women falls.

And similarly, as the number of women entering a male-dominated field increases, the compensation falls.   The increase of women going into law is given as an example of that.
3w.nytimes.com/2016/03/20/upshot/as-women-take-over-a-male-dominated-field-the-pay-drops.html?_r=0