I don't get one thing. If only 18% of the tech graduates are women, why do people (see wsj articles and random blogs) complain about companies "gender imbalance"[1] (not hiring 50% women and 50% men)? Wouldn't that be positive discrimination? As this article states, 18.2% of the graduates are women, but only 15% of the employees share the same gender, so the gap is 3.2%. Personally, I don't consider that 3.2% as bein…
Your reasoning would hold if you could assume identical skill distributions between men and women graduates. However, it seems somewhere between possible and likely that women graduates are of higher average skill than the men graduating. With so many barriers and cultural impedances for a woman pursuing tech, it takes at least the same skill (to pass the classes) as their male classmates, plus enough extra competency to ward off the detractors and skeptics that men don't have to deal with.
Again, I'm not saying this is reality, I certainly don't have the statistics to back it up. But it fits my experiences pretty well, and I think your analysis probably is too simplistic to be useful.
And, in regards to your second point, about starting much earlier: I absolutely agree. The more the culture changes, the less this will be an issue.