A tower filled with shredded U.S. currency in the lobby of the Federal Reserve Bank of Philadelphia.

Paul Calem et al. of the Phillie Fed posted Redefault Risk in the Aftermath of the Mortgage Crisis: Why Did Modifications Improve More Than Self-Cures? The abstract reads,

This paper examines the redefault rate of mortgages that were selected for modification during 2008–2011, compared with that of similarly situated self-cured mortgages during the same period. We find that while the performance of both modified and self-cured loans improved dramatically over this period, the decline in the redefault rate for modified loans was substantially larger, and we attribute this difference to a few key factors. First, the repayment terms provided by modifications became increasingly generous, including the more frequent offering of principal reduction, resulting in greater financial relief to borrowers. Second, the later modifications also benefited from improving economic conditions — modification became more effective as unemployment rates declined and home prices recovered. Third, we find that the difference in redefault rate improvement between modified loans and self-cured loans is not fully explained by observable risk and economic variables. We attribute this residual difference to the servicers’ learning process — so-called learning by doing. Early in the mortgage crisis, many servicers had limited experience selecting the best borrowers for modification. As modification activity increased, lenders became more adept at screening borrowers for modification eligibility and in selecting appropriate modification terms.

The big question, of course, is what does this all tell us about preparing for the next crisis? That crisis, no doubt, won’t be a repeat of the last one. But it will likely rhyme with it enough — falling home prices, increasing defaults — that we can draw some lessons. One is that we did not use principal reductions fast enough to make a big difference in how the crisis played out. There were a lot of reason for this, some legit and some not. But if it is good public policy overall, we should set up mechanisms to deploy principal reduction early in the next crisis so that we do not need to navigate all of the arguments about moral hazard while knee deep in it.