We investigate whether providers of high frequency news analytics affect the stock market. As identification, we exploit a unique experiment based on differences in news event classifications between different product releases of a major provider of news analytics. We document a causal effect of...

The methods of Michael R. Gibbons and Wayne Ferson (1985) are extended, relaxing the assumption that expected returns are linear functions of predetermined instruments. A model of conditional mean-variance spanning generalizes G. Huberman and S. Kandel (1987). The empirical results indicate that...

This paper examines the risks and returns of long-term low-grade bonds for the period 1977-89. The authors find (1) low-grade bonds realized higher returns than higher-grade bonds and lower returns than common stocks, and low-grade bonds exhibited less volatility than higher-grade bonds due to...

This article develops a model of the upstairs market where order size, beliefs, and prices are determined endogenously. We test the model's predictions using unique data for 5,625 equity trades during the period 1985 to 1992 that are known to be upstairs transactions and are identified as either...

The capital asset pricing model implies that the market portfolio is efficient and expected returns are linearly related to betas. Many do not view these implications as separate, since either implies the other, but the authors demonstrate that either can hold nearly perfectly while the other...

Tests of asset-pricing models are developed that allow expected risk premiums and market betas to vary over time. These tests exploit the relation between expected excess returns and current market values. Using weekly data for 1963-82 on ten common stock portfolios formed according to equity...

Sample evidence about the predictability of monthly stock returns is considered from the perspective of a risk-averse Bayesian investor who must allocate funds between stocks and cash. The investor uses the sample evidence to update prior beliefs about the parameters in a regression of stock...

The authors characterize the sets of mimicking positions whose returns can serve in place of factors in an exact K-factor arbitrage pricing relation for a set of N assets. All of the sets are K-dimensional nonsingular linear transformations of each other. The authors interpret three examples of...