Financial frictions and real implications of macroprudential policies

I model a number of imperfections in financial intermediation that have implications for real economic activity in a production economy with technological risk. Partially opaque firms are financed by both debt and insider equity. Banks have market power over borrowers. There can be a prior bias in public beliefs about aggregate productivity (business sentiment). I investigate the dependence of equilibrium on the biased business sentiment and a prudential policy instrument (a convex dependence of bank capital requirements on the quantity of uncollateralized credit). Loss given default can be reduced by both a monetary restriction and a macroprudential restriction. Real implications of both are very similar in the aggregate, but macroprudential policies are more advantageous for bank earnings. On the other hand, the policies considered here are unable to reduce the number of defaulting firms (default frequency). Economic activity is highly sensitive to "leaning against the wind" actions on both fronts, so that using a macroprudential instrument to intervene against an asset price bubble has tangible welfare costs comparable to those of a monetary restriction. The costs can be offset by fine tuning capital charges as a function of corporate governance on the borrower side (specifically, by discouraging limited liability of borrowing firm managers).