Insecure debt

We analyse bank runs under fundamental and asset liquidity risk, adopting a realistic description of bank default. We obtain an unique run equilibrium, even as fundamental risk becomes arbitrarily small. When safe returns are securitized and pledged to repo debt, funding costs are reduced but risk becomes concentrated on unsecured debt. We show the private choice of repo debt leads to more frequent unsecured debt runs. Thus satisfying safety demand via secured debt creates risk directly. Collateral fire sales upon default may reduce its liquidity and lead to higher haircuts, which further increase the frequency of runs.