What are the macroeconomic consequences of changing aggregate lending standards in residential mortgage markets, as measured by loan-to-value (LTV) ratios? In a structural VAR, GDP and business investment increase following an expansionary LTV shock. Residential investment, by contrast, falls, a...

This paper investigates the optimal monetary policy response to a shock to collateral when policymakers act under discretion and face model uncertainty. The analysis is based on a New Keynesian model where banks supply loans to transaction constrained consumers. Our results confirm the...