Another study quizzed graduating master’s degree students who had received job offers about whether they had simply accepted the offered starting salary or had tried to negotiate for more. Four times as many men — 51 percent of the men vs. 12.5 percent of the women — said they had pushed for a better deal. Not surprisingly, those who negotiated tended to be rewarded — they got 7.4 percent more, on average — compared with those who did not negotiate.
A Carnegie Mellon professor has figured out why men make more than women for the same job.
I actually figured that out myself the first time I heard about it. Salaries are negotiable. You can’t pay someone less than they’re willing to work for. Hence, women must be willing to work for less money. It’s the only possible explanation.
UPDATE: I should have emphasized that 7.4 percent is just the difference in starting salaries. If we make the reasonable assumption that men continue to be more aggressive in seeking raises and promotions throughout their careers, the monetary difference potentially becomes very large indeed.