We propose a new theory of systemic risk based on Knightian uncertainty (or "ambiguity"). We show that, due to uncertainty aversion, beliefs on future asset returns are endogenous, and bad news on one asset class induces investors to be more pessimistic about other asset classes as well. This...

Macroprudential stress tests have been employed by regulators in the United States and Europe to assess and address the solvency condition of financial firms in adverse macroeconomic scenarios. We provide a test of these stress tests by comparing their risk assessments and outcomes to those from...

Macroprudential stress tests have been employed by regulators in the United States and Europe to assess and address the solvency condition of financial firms in adverse macroeconomic scenarios. We provide a test of these stress tests by comparing their risk assessments and outcomes to those from...

An intricate web of claims and obligations ties together the balance sheets of a wide variety of financial institutions. Under the occurrence of default, these interbank claims generate externalities across institutions and possibly disseminate defaults and bankruptcy. Building on a simple model...

Can banks maintain their advantage as liquidity providers when they are heavily exposed to a financial crisis? The standard argument - that banks can - hinges on deposit inflows that are seeking a safe haven and provide banks with a natural hedge to fund drawn credit lines and other commitments....

A regulator resolving a bank faces two audiences: depositors, who may run if they believe the regulator will not provide capital, and banks, which may take excess risk if they believe the regulator will provide capital. When the regulator's cost of injecting capital is private information, it...

We present a simple model of an economy with heterogeneous banks that may be funded with uninsured deposits and equity capital. Capital serves to ameliorate a moral hazard problem in the choice of risk. There is a fixed aggregate supply of bank capital, so the cost of capital is endogenous. A...

We analyze the cyclical effects of moving from risk-insensitive (Basel I) to risk-sensitive (Basel II) capital requirements in the context of a dynamic equilibrium model of relationship lending in which banks are unable to access the equity markets every period. Banks anticipate that shocks to...

We analyze banks' systemic risk taking in a simple dynamic general equilibrium model. Banks collect funds from savers and make loans to firms. Banks are owned by risk-neutral bankers who provide the equity needed to comply with capital requirements. Bankers decide their (unobservable) exposure...

We examine the pricing of financial crash insurance during the 2007-2009 financial crisis in U.S. option markets. A large amount of aggregate tail risk is missing from the price of financial sector crash insurance during the financial crisis. The difference in costs of out-of-the-money put...