You think? I thought the typical blame was placed on high school stereotypes; as you point out, by college most women want nothing to do with engineering or computer science. (Hence FIRST, among other efforts.)
Another explanation I've heard is that women are smart enough to see that the expected value of going into medicine or law is substantially higher. Given the social status and economics are better, why wouldn't they enter those fields instead?
There seem to be differences even earlier than high-school stereotypes or economics become a consideration, though--- my after-school Logo class for elementary-aged students was mostly boys too. Due to girls just not being interested? Due to parents pushing their male v. female children in different directions? Something else? Whatever the reason(s), it's pretty early overall, I think; all the techies I knew in high school began becoming techies quite a bit before high school.
Another explanation I've heard is that women are smart enough to see that the expected value of going into medicine or law is substantially higher. Given the social status and economics are better, why wouldn't they enter those fields instead?