The Urban Institute’s Housing Finance Policy Center has issued a report, Principal Reduction and the GSEs: The Moment for a Big Impact Has Passed. It opens,

The Federal Housing Finance Agency (FHFA) prohibits Fannie Mae and Freddie Mac (the government-sponsored enterprises, or GSEs) from unilaterally reducing the principal balance of loans that they guarantee, known as principal reduction. When director Ed DeMarco established the prohibition, he was concerned that reducing principal would cost the GSEs too much, not only in setting up the systems required to implement it, but also— and to him more important — in encouraging borrowers to default in order to receive the benefit. DeMarco’s position generated significant controversy, as advocates viewed principal reduction as a critical tool for reducing borrower distress and pointed out that the program the Obama administration had put forward to provide the relief had largely eliminated the cost to the GSEs, including the moral hazard. We believe that at the time the advocates had the better side of the argument.

The FHFA is now revisiting that prohibition, though in a very different economic environment than the one faced by Director DeMarco. Home prices are up 35.4 percent since the trough in 2011, adding $5 trillion in home equity and reducing the number of underwater homeowners from a peak of 25 percent to 10 percent. This means that far fewer borrowers would likely benefit under a GSE principal reduction program today. (1, footnote omitted)

Principal reduction was highly disfavored at the start of the financial crisis as it was perceived as a sort of giveaway to irresponsible borrowers. Some academics have disputed this characterization, but it probably remains a political reality.

In any event, I think this report has the analysis of the current situation right — the time for principal reduction has passed. But it is worth considering the conditions under which it might be appropriate in the future (for that next crisis, or the one after that). The authors make four  assumptions for a politically feasible principal reduction program:

1. borrowers must be delinquent at the time the program is announced, in order to avoid the moral hazard of encouraging borrowers to default;
2. borrowers must be underwater;
3. the house must be owner-occupied; and
4. the principal reduction is in the economic interest of Fannie and Freddie.

It is worth noting that during the Great Depression, the federal government figured out ways to reduce the burden of rapidly dropping house prices on lenders and borrowers alike without resorting to principal reduction much. Borrowers benefited from longer repayment terms and lower interest rates. Below-market interest rates are similar to principal reduction because they also reduce monthly costs for borrowers. They are also politically more feasible. It would be great to have a Plan B stored away at the FHFA, the FHA and the VA that outlines a systematic response to a nation-wide drop in housing prices. It could involve principal reduction but it does not need to.