Originally Posted by Punky
i guess ppl are older and work while they study so they dont have time for b/s and stuff.
I assume an even bigger reason is that post-grad students are even more motivated to their studies. Some of the students who don't have a gruduate may study only because they feel they have to study, e.g. to get a job. (Sounds too familiar to me.) But I assume post-grad students study more because they want to, not that much because they'd feel they have to.