We develop a q theory of investment with endogenous leverage, payout, hedging, and risk-taking dynamics. The key frictions are costly equity issuance and incomplete markets. We show that the marginal source of external financing on an on-going basis is debt. The firm lowers its debt when making...

We propose a dynamic theory of banking where deposits play the role of productive capital as in the classical Q-theory of investment for non-financial firms. A key conceptual innovation of our theory is that the stock of deposits cannot be perfectly controlled by the bank. Demand deposit...

We propose a dynamic theory of banking where the role of deposits is akin to that of productive capital in the classical q-theory of investment. As a cheap source of leverage, deposits typically create value for banks, but the marginal q of deposits can be negative. Deposit accounts commit banks...

We propose a model of sovereign debt where countries vary in their level of financial development, defined as the extent to which countries can hedge rare disasters in international capital markets. We show that low levels of financial development generate the "debt intolerance" phenomenon that...

We estimate a model of damage to corporate earnings from COVID-19. An unexpected pandemic lowers current earnings due to costly mitigation and reduces growth rates. Damage depends on the expected arrival of a vaccine that reverts earnings to normal. Using this model, we infer from analysts'...

We develop a model of pandemic risk management and firm valuation. We introduce aggregate transmission shocks into an epidemic model and link valuations to infections via an asset-pricing framework with vaccines. Infections lower earnings growth but firms can mitigate damages. We estimate a...

We provide the planner's solution to a model where households learn from exogenous natural disaster arrivals about arrival rates and spend to mitigate future damages. Mitigation cannot be decentralized due to positive externalities from curtailing aggregate risks. First-best can be implemented...

We develop a dynamic portfolio-choice model with illiquid alternative assets to analyze conditions under which the "Endowment Model," used by some large institutional investors such as university endowments, does or does not work. The alternative asset has a lock-up, but can be voluntarily...

We develop a tractable incomplete-markets model with an earnings process Y subject to permanent shocks and borrowing constraints. Financial frictions cause the marginal (certainty equivalent) value of wealth W to be greater than unity and decrease with liquidity w = W/Y . Additionally, financial...