I show that, in a benchmark model, debt securities minimize the welfare losses associated with the moral hazards of excessive risk-taking and lax effort. For any security design, the variance of the security payoff is a statistic that summarizes these welfare losses. Debt securities have the least variance, among all limited liability securities with the same expected value. In other models, mixtures of debt and equity are exactly optimal, and pure debt securities are approximately optimal. I study both static and dynamic security design problems, and show that these two types of problems are equivalent. I use moral hazard in mortgage lending as a recurring example, but my results apply to other corporate finance and principal-agent problems.

This article studies the optimal design of corporate taxes when firms have private information about future investment opportunities and face financial constraints. A government whose goal is to efficiently raise a given amount of revenue from its corporate sector should attempt to tax unconstrained firms, which value resources inside the firm less than financially constrained firms. We show that a corporate payout tax (a tax on dividends and share repurchases) can both separate constrained and unconstrained firms and raise revenue and is therefore optimal. Our quantitative analysis implies that a revenue-neutral switch from profit taxation to payout taxation would increase the overall value of existing firms and new entrants by 7%. This switch could be implemented in the current US tax system by making retained earnings fully deductible.

We estimate the causal effect of sovereign default on the equity returns of Argentine firms. We identify this effect by exploiting changes in the probability of Argentine sovereign default induced by legal rulings in the case of NML Capital, Ltd. v. Republic of Argentina. We find that a 10 percent increase in the probability of default causes a 6 percent decline in the value of Argentine equities and a 1 percent depreciation of a measure of the exchange rate. We examine the channels through which a sovereign default may affect the economy.

We analyze efficiency and nonfundamental volatility in a class of generalized beauty-contest economies with endogenous information. As in models of rational-expectations equilibria, agents learn about exogenous states and endogenous aggregate actions. As in models of rational inattention, agents choose their information structures subject to a cost. We identify conditions on information costs that guarantee the existence of efficient or inefficient equilibria; we further identify conditions that guarantee the existence or nonexistence of equilibria with zero nonfundamental volatility. Mutual information, the cost typically assumed in rational-inattention models, guarantees the existence of an efficient equilibrium with zero nonfundamental volatility.

We derive a new cost of information in rational inattention problems, the neighborhood-based cost functions, starting from the observation that many settings involve exogenous states with a topological structure. These cost functions are uniformly posterior separable and capture notions of perceptual distance. This second property ensures that neighborhood-based costs, unlike mutual information, make accurate predictions about behavior in perceptual experiments. We compare the implications of our neighborhood-based cost functions with those of the mutual information in a series of applications: perceptual judgments, the general environment of binary choice, regime-change games, and linear-quadratic-Gaussian settings.

We model the widespread failure of contracts to share risk using available indices. A borrower and lender can share risk by conditioning repayments on an index. The lender has private information about the ability of this index to measure the true state that the borrower would like to hedge. The lender is risk‐averse and thus requires a premium to insure the borrower. The borrower, however, might be paying something for nothing if the index is a poor measure of the true state. We provide sufficient conditions for this effect to cause the borrower to choose a nonindexed contract instead.

We use equity returns to construct a time-varying measure of the zero-beta interest rate: the expected return of a stock portfolio orthogonal to the stochastic discount factor. In contrast to safe rates, the zero-beta rate fits the aggregate consumption Euler equation remarkably well both unconditionally and conditional on monetary policy shocks and is high, volatile, and persistent enough to explain the average return and most of the volatility of the market portfolio. The puzzle is why safe rates are so low, stable, and disconnected from both consumption and the zero-beta rate.

We document a regime change in the Treasury market post-Global Financial Crisis (GFC): dealers switched from net short to net long Treasury bonds. We construct “net-long” and “net-short” curves that account for balance sheet and financing costs, and show that actual yields moved from the net short curve pre-GFC to the net long curve post-GFC. Our theory shows the regime shift caused negative swap spreads and co-movement among swap spreads, dealer positions, and covered-interest-parity violations. Furthermore, the effects of various monetary and regulatory policies are regime-dependent. We highlight Treasury supply as a plausible driver of this regime shift.

Violations of no-arbitrage conditions measure the shadow cost of intermediary constraints. Intermediary asset pricing and intertemporal hedging together imply that the risk of these constraints tightening is priced. We describe a “forward CIP trading strategy” that bets on CIP violations shrinking and show that its returns help identify the price of this risk. This strategy yields the highest returns for currency pairs associated with the carry trade. The strategy’s risk substantially contributes to the volatility of the stochastic discount factor, is correlated with both other near-arbitrages and intermediary wealth measures, and appears to be consistently priced across various asset classes.