Title: HBANK: Monetary Policy with Heterogeneous Banks

Abstract: We study monetary, liquidity, and macroprudential policy transmission in a Heterogeneous Bank New Keynesian (HBANK) model that is solved in sequence space. Using a sufficient-statistic approach, we show that the combination of incomplete markets and costly bank insolvency breaks the “as-if” result, generating substantial amplification of policy shocks relative to the representative-bank benchmark. There is a trade-off between macroeconomic and financial stabilization: contractionary monetary policy worsens financial stability by raising the likelihood of bank insolvency in the lower tail of the bank size distribution. We enrich our baseline framework with departures from perfect deposit and credit market competition and apply it to the study of monetary, forward guidance, macroprudential, and reserve requirement policies. We validate our model empirically with novel cross-sectional and time-series facts on U.S. commercial banks.