Re: "Gender Gap"?
IMO, the "Gender Gap" conclusion is suspect. It's not evident in any IT organization I've ever worked in...there were also great deal of women in supervisory positions which are the higher salaried positions. I couldn't find any information on how the "gap" was measured.
My suspicions are around the data manipulation. Were employee salaries just collected and analyzed based on gender? If so, of course women will have lower salaries because many people still believe that children need to be raised by their own parents. This results traditionally and practically in the mother taking time off to 1) give birth to the kids and 2) often raising the children until they are of school age. This time out of the work force means that at any particular age, many women have less experience than men equal to their age. There's nothing wrong with it - *someone* has to do the right thing with children and it's usually the mother. If men had the babies, we'd be seeing the same statistics in reverse.
In my experience, women who have the exact same background, skills, experience and competency get the exact same pay as men - especially in high tech fields.
Finally, it is interesting to note that women who have decided to take the career route and forego children resent the actions of women who take time off work to run the kids to soccer, stay home when the kids are sick or take them to the doctor, etc. These mothers who put in less work for the company, expect to progress through the ranks at the same rate as the other women who cover for them when they are not working, and are often surprised by the attitudes of the career women.