An IV Hazard Model of Loan Default with an Application to Subprime Mortgage Cohorts

ABSTRACT I develop a control function methodology robust to endogenous or mismeasured regressors in hazard models. Applying the estimator to the subprime mortgage crisis, I quantify what caused the foreclosure rate to triple across the 2003 to 2007 subprime cohorts. To identify the elasticity of default to housing prices, I use various home price instruments including historical variation in home price cyclicality. Loose credit played a significant role in the crisis, but much of the increase in defaults across cohorts was caused by price declines unrelated to lending standards, with a 10% price decline increasing subprime mortgage default rates by 50%.