If you haven't read SuperFreakonomics and you're interested in this comment, get a copy of the book: the first chapter is about how the "decline" of the education system is linked to rising professional opportunities for women.

It used to be that highly competent women often became teachers because that was the only thing available to them. Now women can be professors, work in business, etc.

Note: this is not an argument for restricting female choice or anything else. It's about diagnosing how one (good) thing can lead to unintended consequences.