Jason Delisle and Jason Richwine write,

the government’s official method for estimating cost is incomplete. It fails to incorporate the cost of the market risk associated with expecting future loan repayments. So-called “fair-value accounting,” an accounting method favored by the vast majority of finance economists as well as the CBO itself, factors in the cost of market risk. The difference transforms the official student-loan “profit” into a loss, for a budgetary swing of $279 billion over ten years. That figure demonstrates why the stakes are so high in the debate about fair-value accounting.

I recommend the entire essay. I would like to make changes to government accounting a top economic priority, because I think that avoiding a debt crisis ought to be a top priority.

If you ignore risk, then the government can appear to make a profit with all sorts of loans and loan-guarantee programs. I would go beyond fair-value accounting and subject the government budget to stress-testing, to give a measure of risk exposure.