> So your degree is free unless other people are willing to pay you to have it? In which case it costs you money?
yes. If your degree is in an area where you are unlikely to recuperate the initial investment of the education, then it effectively becomes free (i.e., paid for by society). I like this because some degrees that aren't productive, but has a genuine societal benefit (like studying history or something), can be funded this way. The person doing said degree has to really like it, and give up a high salary to do so.
Degrees which _are_ economically productive will very easily reach the threshold for repayment of the loan, and thus the cost is borne by the employer/employee, who then ultimately benefit the most out of the degree (and therefore, justifies the relief to taxpayers for the cost of the loan).
And because i believe most people are not willing to sacrifice their future economic gains just to have a free degree, i believe most will look to doing one which will become economically productive. But there are a few passionate individuals who look beyond their own economic gains, and this method allows those people to exist and contribute their passion to society.