This paper studies optimal financial policy in a world where the financial sector can become excessively optimistic. I decompose the welfare effects of bank capital regulation to demonstrate the effects of exuberance and its interaction with incentive problems in banking. The optimal policy...

This paper studies leverage regulation and monetary policy when equity investors and/or creditors have distorted beliefs relative to a planner. We characterize how the optimal leverage regulation responds to arbitrary changes in investors' and creditors' beliefs and relate our results to...

This paper studies optimal second-best corrective regulation, when some agents/activities cannot be perfectly regulated. We show that policy elasticities and Pigouvian wedges are sufficient statistics to characterize the marginal welfare impact of regulatory policies in a large class of...

This paper studies optimal financial policy in a world where the financial sector can become excessively optimistic. I decompose the welfare effects of bank capital regulation to demonstrate the effects of exuberance and its interaction with incentive problems in banking. The optimal policy...

The 2007-9 .financial crisis began with increased uncertainty over funding conditions in money markets. We show that funding uncertainty can explain diverse elements of commercial banks behaviour during the crisis, including:(i) reductions in lending volumes, balance sheets, and...

Banks create excessive systemic risk through leverage and maturity mismatch, as financial constraints introduce welfare-reducing pecuniary externalities.  Macroprudential regulators can achieve efficiency with simple linear constraints on banks' balance sheets, which require less information...

We analyze a general equilibrium model in which financial institutions generate endogenous systemic risk. Banks optimally select correlated investments and thereby expose themselves to re-sale risk so as to sharpen their incentives. Systemic risk is therefore a natural consequence of banks'...