- I would always suggest studying that which you are passionate about rather than that which will make you the most money.
I don't have much disagreement with this advice, but I think it has to come with the caveat that school these days isn't simply about earning potential, but weighing that potential against what you paid for school. I have a BA in history and a law degree. I paid a fraction of tuition for both undergrad and law school due to scholarships (I also worked during undergrad but didn't make enough to really put a dent in anything except room and board.)
I consider myself lucky to not carry the same debt burden as most of my peers, but it is still ultimately an encumbrance and it colors literally every decision I make, both short and long-term. If you are like me and independence is a pivotal element of happiness, you should consider if your academic passion will end up becoming a hinderance in itself simply because what you pay and what you can earn won't balance out.