Three entrepreneurs are offering a share of their life’s income in exchange for cash upfront and have banded together to form the Thrust Fund, an online marketplace for such personal investments.

Kjerstin Erickson, a 26-year-old Stanford graduate who founded a non-profit called FORGE that rebuilds community services in Sub-Saharan African refugee camps, is offering 6 percent of her life’s income for $600,000.

(quoted here). A closer look reveals that this is more of clever marketing play to interest donors in supporting a philanthropy. What, for example, does Kjerstin want do with the money? She writes:

Some people may think that it's crazy to give up a percentage of your income for the sake of scaling a nonprofit venture. But to me, it makes perfect sense.

Well it does make perfect sense for Kjerstin but not so much for a profit-seeking investor (moreover any income would be taxed twice, a problem with equity financing in general but especially so here without corporate tax breaks.) Investing in just one entrepreneur is also risky – why not subdivide the investment and invest in many?

Jeff at Cheap Talk raises a larger but closely related issue, "Why don’t we replace student loans with student shares?" In fact, Milton Friedman advocated income contingent loans in 1955.

The counterpart for education would be to "buy" a share in an individual's earning prospects: to advance him the funds needed to finance his training on condition that he agree to pay the lender a specified fraction of his future earnings. In this way, a lender would get back more than his initial investment from relatively successful individuals, which would compensate for the failure to recoup his original investment from the unsuccessful. There seems no legal obstacle to private contracts of this kind, even though they are economically equivalent to the purchase of a share in an individual's earning capacity and thus to partial slavery …One way to do this is to have government engage in equity investment in human beings of the kind described above. …The individual would agree in return to pay to the government in each future year x per cent of his earnings in excess of y dollars for each $1,000 that he gets in this way. This payment could easily be combined with payment of income tax and so involve a minimum of additional administrative expense. The base sum, $y, should be set equal to estimated average–or perhaps modal–earnings without the specialized training; the fraction of earnings paid, x, should be calculated so as to make the whole project self-financing.

Another Nobelist of a more liberal stripe, James Tobin, helped to implement an income-contingent tuition program at Yale in the 1970s. Alas, the program was terminated largely due to rent-seeking when many Yale graduates become so successful that the repayment amounts became substantial and the nouveau riche chose to default (also here).

Bill Clinton later tried to take the idea national but it didn't get very far in the United States. (Not coincidentally Clinton had been a beneficiary of the Yale program.)

Australia, however, implemented an income contingent loan program in 1989. Australian students don't pay anything for university when they attend but once their

income reaches a certain threshold they are charged through the income tax system. Many other countries are experimenting with income contingent loans.

Hat tip to Alexander Ooms.