We develop a dynamic general equilibrium model for the positive and normative analysis of macroprudential policies. Optimizing financial intermediaries allocate their scarce net worth together with funds raised from saving households across two lending activities, mortgage and corporate lending....

In the presence of uninsurable idiosyncratic risk, the optimal credit contract allows for the possibility of default. In addition, the optimal contract incorporates a precautionary savings motive over and above what agents would otherwise save. When default is sufficiently high, credit markets...