We use quasi-random access to the Home Affordable Refinance Program (HARP) to identify the causal effect of refinancing a mortgage on borrower balance sheet outcomes. We find that on average, refinancing into a lower-rate mortgage reduced borrowers' default rates on mortgages and nonmortgage...

Fixed-rate mortgages (FRMs) dominate the U.S. mortgage market, with important consequences for household risk management, monetary policy, and systemic risk. In this paper, we show that securitization is a key driver of FRM supply. Our analysis compares the agency and nonagency...