I don't buy many of the points presented, but for different reasons.
Most of the statistics presented, while interesting, are correlations. The commute correlation with salary statistic, for instance. What does that actually mean? Is the longer commute a cause or an effect of a higher salary? This needs to be fleshed out a bit more.
Risk taking: Sigh. Other than the obvious - define "risk", there are so many stereotypes in this that its not funny. There are risk taking women; there are non-risk taking men. In addition, risk itself can be eased a bit. Isn't that what an emergency fund is all about? Even studying the career arcs of men and women with some savings, where the perception of individual risk is simliar, would be useful than what is presented here.
Children: fair enough. Not to mention that even when a woman earns more money that profit is immediately sent to a stiff day-care bill. Perhaps this whole thread should be retitled, "why men are allowed to keep more money".
Not that you've got me started, here are my thoughts and stereotypes. As a woman, I'm telling it like it is, and this is me...:
1. Men instinctually know that the HR department is not their friend. HR exists (after handing out the paychecks) to provide cover for a company against regulations and grievances, not to help employees.
2. Women are crappy negotiators in the workplace for people, period. Many women work for other women who are themselves earning less money than they should. Ask yourself - if you are in that situation, are you really able to sum up the cojones (sic) needed to negotiate a subordinate's salary?
3. Women value a workplace that has less strife and are more likely to back down if things get hot in a salary negotiation (perhaps that's a good definition of risk). Men's tolerance for that kind of heat is a lot higher.
4. Women are less likely to know, and therefore won't ask for, side deals and addendums during their initial offer. They think of a deal as a take or leave proposition. This I can tell you happened to me. I put some of my story in my journal. After the initial breakdown of salary negotiations, my would-be-boss, who had been recently hired, told me that he had himself negotiated a pay based on performance clause. If we re-started the negotiations, would you be interested in this? I said yes. In addition, he coached me on how to ask for it IN WRITING during my chat with the HR Director.
And FYI, what's so awful about engineering? Sheesh.