Technological Innovation in Mortgage Underwriting and the Growth in Credit: 1985-2015

The application of information technology to finance, or “fintech,” is expected to revolutionize many aspects of borrowing and lending in the future, but technology has been reshaping consumer and mortgage lending for many years. During the 1990s computerization allowed mortgage lenders to reduce loan-processing times and largely replace human-based assessment of credit risk with default predictions generated by sophisticated empirical models. Debt-to-income ratios at origination add little to the predictive power of these models, so the new automated underwriting systems allowed higher debt-to-income ratios than previous underwriting guidelines would have typically accepted. In this way, technology brought about an exogenous change in lending standards, which helped raise the homeownership rate and encourage the conversion of rental properties to owner-occupied ones, but did not have large effects on housing prices. Technological innovation in mortgage underwriting may have allowed the 2000s housing boom to grow, however, because it enhanced the ability of both borrowers and lenders to act on optimistic beliefs about future house-price growth.