How Do Mortgage Refinances Affect Debt, Default, and Spending? Evidence from HARP

We use quasi-random access to the Home Affordable Refinance Program (HARP) to identify the causal effect of refinancing into a lower-rate mortgage on borrower balance sheet outcomes. Refinancing substantially reduces borrower default rates on mortgages and other debt. Refinancing also causes borrowers to expand their use of debt instruments, such as auto loans, home equity lines, and other consumer debts that are proxies for spending. Borrowers that appear more constrained ex ante grow these debts more strongly after refinancing but also pay down credit card balances by more. These borrowers also have lower take-up of the refinancing opportunity.