We propose a theory of credit lines provided by banks to firms as a form of monitored liquidity insurance. Bank monitoring and resulting revocations help control illiquidityseeking behavior of firms insured by credit lines. The cost of credit lines is thus greater for firms with high liquidity risk, which in turn are likely to use cash instead of credit lines. We test this implication for corporate liquidity management by identifying exogenous shocks to liquidity risk of firms in corporate bond and equity markets. Firms experiencing increases in liquidity risk move out of credit lines and into cash holdings.

and the Boston Federal Reserve Bank. The views expressed herein are those of the authors and do not necessarily reflect the views of the National Bureau of Economic Research. NBER working papers are circulated for discussion and comment purposes. They have not been peerreviewed or been subject to the review by the NBER Board of Directors that accompanies official NBER publications.

We present a general equilibrium model of intermediation designed to capture some of the key features of the modern financial system. The model incorporates financial constraints and state-contingent contracts, and contains a clearly defined pecuniary externality associated with asset fire sales during periods of stress. If a sufficiently severe shock occurs during a credit expansion, this externality is capable of generating a systemic financial crisis that may be self-fulfilling. Our model suggests that financial innovation and greater macroeconomic stability may have made financial crises in developed countries less likely than in the past but potentially more severe. Copyright � Bank of England.

The unprecedented fiscal and monetary policy support in the wake of the COVID-19 pandemic has brought to the fore concerns that cheap credit could fuel the financing of zombie firms—that is, firms that are unable to generate enough profits to cover debt-servicing costs and that need to borrow to stay alive. Many observers have recently commented that zombie firms may crowd out lending to productive firms and erode the strength of the U.S. economy.