We develop a theory of optimal financing for R&D-intensive firms that uses their unique features—large capital outlays, long gestation periods, high upside, and low probabilities of R&D success—that explains three prominent stylized facts about these firms: their relatively low use of debt,...

How does competition affect innovation and how it is financed in R&D-intensive firms? We study the interaction between competition, R&D investments, and the financing choices of such firms using data on biopharmaceutical firms. To motivate the empirical hypotheses, we develop a model for such...

The high cost of capital for firms conducting medical research and development (R&D) has been partly attributed to the government risk facing investors in medical innovation. This risk slows down medical innovation because investors must be compensated for it. We analyze new and simple financial...

During the week of August 6, 2007, a number of quantitative long/short equity hedge funds experienced unprecedented losses. It has been hypothesized that a coordinated deleveraging of similarly constructed portfolios caused this temporary dislocation in the market. Using the simulated returns of...

This paper examines the stochastic properties of aggregate macroeconomic time series from the standpoint of fractionally integrated models, and focuses on the persistence of economic shocks. We develop a simple macroeconomic model that exhibits long-term dependence, a consequence of aggregation...

We compare and contrast the expected duration and number of infections and deaths averted among several designs for clinical trials of COVID-19 vaccine candidates, including traditional randomized clinical trials and adaptive and human challenge trials. Using epidemiological models calibrated to...

We examine the finite sample properties of the variance ratio test of the random walk hypothesis via Monte Carlo simulations under two null and three alternative hypotheses. These results are compared to the performance of the Dickey-Fuller t and the Box-Pierce Q statistics. Under the null...

We propose several econometric measures of systemic risk to capture the interconnectedness among the monthly returns of hedge funds, banks, brokers, and insurance companies based on principal components analysis and Granger-causality tests. We find that all four sectors have become highly...

The confluence of three trends in the U.S. residential housing market---rising home prices, declining interest rates, and near-frictionless refinancing opportunities---led to vastly increased systemic risk in the financial system. Individually, each of these trends is benign, but when they occur...

This paper attempts to assess whether money can generate persistent economic" fluctuations in dynamic general equilibrium models of the business cycle. We show that a small" nominal friction in the goods market can make the response of output to monetary shocks large" and persistent if it is...