> How do you know that your graduates are or aren't making more than 50k? How do you know that you're getting your 17%?

you can ask students to fill out and sign, as a condition of admission, forms authorizing the IRS to hand over their tax returns, in advance. it wouldn't be very hard to contract with a law firm to take the results and check to see if they had more than 50k of income, while ignoring/discarding all other information.

or just have them sign a thing saying they'll do X. if they lie, they're probably committing fraud. most folks don't run around committing high dollar fraud.

> Aside from that, you're essentially giving your students a loan and then having them repay it once they start earning money. How is this any different than a regular student loan (but with way more risk on your end)?

the point of this model is to lower risk for the student, and hope that the value you're providing is sufficient to offset the additional risk you're accepting.