Taming Systemically Important Financial Institutions

We model a systemically important financial institution that is too big (or too interconnected) to fail. Without credible regulation and strong supervision, the shareholders of this institution might deliberately let its managers take excessive risk. We propose a solution to this problem, showing how insurance against systemic shocks can be provided without generating moral hazard. The solution involves levying a systemic tax needed to cover the costs of future crises and more importantly establishing a systemic risk authority endowed with special resolution powers, including the control of bankers’ compensation packages during crisis periods.     

Dynamic Security Design: Convergence to Continuous Time and Asset Pricing Implications

An entrepreneur with limited liability needs to finance an infinite horizon investment project. An agency problem arises because she can divert operating cash flows before reporting them to the financiers. We first study the optimal contract in discrete time. This contract can be implemented by cash reserves, debt, and equity. The latter is split between the financiers and the entrepreneur and pays dividends when retained earnings reach a threshold. To provide appropriate incentives to the entrepreneur, the firm is downsized when it runs short of cash. We then study the continuous-time limit of the model. We prove the convergence of the discrete-time value functions and optimal contracts. Our analysis yields rich implications for the dynamics of security prices. Stock prices follow a diffusion reflected at the dividend barrier and absorbed at 0. Their volatility, as well as the leverage ratio of the firm, increase after bad performance. Stock prices and book-to-market ratios are in a non-monotonic relationship. A more severe agency problem entails lower price-earning ratios and firm liquidity and higher default risk.     

Aggregate Investment Externalities and Macroprudential Regulation

Evidence suggests that banks tend to lend a lot during booms and very little during recessions. We propose a simple explanation for this phenomenon. We show that instead of dampening productivity shocks, the banking sector tends to exacerbate them, leading to excessive fluctuations of bank credit, output, and asset prices. Our explanation relies on three ingredients that are characteristic of modern banks’ activities: moral hazard, high exposure to aggregate shocks, and the ease with which capital can be reallocated to its most productive use. At the competitive equilibrium, banks offer privately optimal contracts to their investors, but these contracts are not socially optimal: banks reallocate capital excessively upon aggregate shocks. This is because banks do not internalize the impact of their decisions on asset prices. We examine the efficacy of possible policy responses to these properties of credit markets, and derive a rationale for macroprudential regulation in the spirit of a Net Stable Funding Ratio.     

Free Cash Flow,Issuance Costs,and Stock Prices

We develop a dynamic model of a firm facing agency costs of free cash flow and external financing costs, and derive an explicit solution for the firm's optimal balance sheet dynamics. Financial frictions affect issuance and dividend policies, the value of cash holdings, and the dynamics of stock prices. The model predicts that the marginal value of cash varies negatively with the stock price, and positively with the volatility of the stock price. This yields novel insights on the asymmetric volatility phenomenon, on risk management policies, and on how business cycles and agency costs affect the volatility of stock returns.