SAs raise all kinds of questions. How many students will lose their jobs and be unable to pay? How much should Wall Street demand as compensation for the risk? Investors typically ask for a smaller slice from students with more lucrative majors. At Purdue, for example, English majors borrowing $10,000 pay 4.52 percent of their future income over nearly 10 years; chemical engineers, 2.57 percent in a bit over seven years.

https://www.bloomberg.com/news/articles/2019-04-09/college-grads-sell-stakes-in-themselves-to-wall-street