True story coming up.
I did my undergrad/master's at Oxford. The course title was "Engineering, Economics, and Management". Supposedly it was roughly 2/3rds of the Engineering course, and 2/3 of the "Economics and Management" course, but when you put it all together it seemed like 3/4 Engineering.
In the last year, there was a 6-month placement, which you were to use as experience to write a thesis. You could choose from anything that fit under any of the three rubrics (Eng, Econ, Mgt), and someone would find you an appropriate advisor, ie a prof from the Engineering School, the Econ department, or the Business school.
The kind of companies we got to show up were mainly banks. There was the occasional engineering company as well as a few household industrials.
I didn't get any of the coveted bank jobs. I did manage to show up very late (thank you Great Western railways) to an engineering interview, and got offered the job anyway. The money on offer was £11K/year, which didn't seem enticing at all, even for an internship. I ended up taking a marketing job at a major chip manufacturer, which was happy to pay 15K. So I rented a place in this little industrial town and got to work on powerpoint for half a year. (I should say I had a great social life, and I know friends who are still there 13 years later.)
So of course one day, I go to visit a coursemate who did manage to get a bank job, at a place that would later be called the giant vampire squid (not sure I agree with the epithet). So, what does he get? £26K a year. Free apartment within walking distance of work, on the South Bank. Gym and pool included. That one bedroom apartment, at that time, was probably 250/week. So basically he's making £38/year.
It's little wonder people want to work in finance when the numbers are that skewed.
How many of my ~30 EEM coursemates went into engineering? I can think of one. Just about everyone else went into finance.
I remember meeting a guy early on who'd started in Engineering. I asked him why he'd quit. He said "One day, I accidentally saw what my manager was making".
Is it a brain drain? Quite possibly. A lot of the brains in finance are fighting a zero sum game with each other. How can I price this derivative a little more smartly than the next guy? How do I grab the arb before another guy does it? How do I get a guy to trade with me and not someone else? How do I get my firm's name on this tombstone?