NBER Publications by Kristopher Gerardi

We document the fact that servicers have been reluctant to renegotiate mortgages since the foreclosure crisis started in 2007, having performed payment reducing modifications on only about 3 percent of seriously delinquent loans. We show that this reluctance does not result from securization: servicers renegotiate similarly small fractions of loans that they hold in their portfolios. Our results are robust to different definitions of renegotiation, including the one most likely to be affected by securitization, and to different definitions of delinquency. Our results are strongest in subsamples in which unobserved heterogeneity between portfolio and securitized loans is likely to be small and for subprime loans. We use a theoretical model to show that redefault risk, the possibility t...

This paper takes a skeptical look at a leading argument about what is causing the foreclosure crisis and distills some potential lessons for policy. We use an economic model to focus on two key decisions: the borrower's choice to default on a mortgage and the lender's subsequent choice whether to renegotiate or "modify" the loan. The theoretical model and econometric analysis illustrate that "unaffordable" loans, defined as those with high mortgage payments relative to income at origination, are unlikely to be the main reason that borrowers decide to default. In addition, this paper provides theoretical results and empirical evidence supporting the hypothesis that the efficiency of foreclosure for investors is a more plausible explanation for the low number of modifications to date than co...

The U.S. mortgage market has experienced phenomenal change over the last 35 years. This paper develops and implements a technique for assessing the impact of changes in the mortgage market on households. Our framework, which is based on the permanent income hypothesis, that allows us to gauge the importance of borrowing constraints by estimating the empirical relationship between the value of a household's home purchase and its future income. We find that over the past several decades, housing markets have become less imperfect in the sense that households are now more able to buy homes whose values are consistent with their long-term income prospects. One issue that has received particular attention is the role that the housing Government Sponsored Enterprises (GSEs), Fannie Mae and Fredd...