I've heard one interesting theory about why these relationships between attractive female teachers and male students are more prevalent nowadays:
1) Modernity and the fight for equal rights has unleashed female sexuality. There's little shaming of female sexual expression anymore. So that's one barrier that's fallen.
2) Female sexual interest, especially when it comes to males, is a lot more uniform than male sexual interest. Guys can like shy girls, fat girls, short girls -- but women generally want the tall, lean, charismatic and gregarious man. Man is happy to reproduce with any female, but women are much more specific about who they will allow to fertilize their eggs.
3) Their sexuality unleashed, these female teachers are going after that type wherever they can, which includes the 27-year-old banging the 15-year-old football captain. No doubt the teenage boys getting laid by their teacher are the ones who would be laid by their peers anyway, not your everyday schoolkid, much less the nerd.
This makes a lot of sense to me. What do you think?