One of my former students who graduates from business school next week has already landed a job with a private-equity firm paying him $240,000 next year, which I can tell you is a lot more than the salary of his former professor who’s more than three decades older. My student tells me with a smile he’ll be able to pay off his student debt way ahead of schedule. But that’s not his real reason for taking the private-equity job. He wants to make gobs of money.

On the other hand, several of my students who will graduate next week tell me they would have liked to go into social work or into the non-profit sector or provide legal services to the poor. One had his heart set on becoming a painter. Another became passionate about archeology and had wanted to go on a dig in the Sahara. But they can’t do any of these things because they have tens of thousands of dollars of debt. They need jobs that pay the rent while they repay their loans.

When they begin their university studies and take out college loans, most students don’t know exactly where their interests lie. That’s what college is all about – discovering what you want to do with your life. But America’s increasing reliance on student loans to pay for higher education is directing millions of young people away from what they really want to do – from careers that could contribute a great deal to their communities and to the nation as a whole, but don’t get them out from under their college loans.

So here’s an idea that might allow more students to pursue their real interests when they graduate: Make repayment of government-subsidized loans depend on how much money they earn. Say everyone has to pay ten percent of their income for the first ten years of their full-time work. And then the loans are considered paid off.

My student who’s landed that private-equity job would pay ten percent of his income for ten years, which would be a hefty sum. My students who go into social work or become artists would pay ten percent of theirs, which would be far less. The private-equity guy would in effect subsidize the social worker and artist. And why not? This way all of them can follow their callings.