Wayne E. Ferson

The Variation of Economic Risk Premiums

This paper provides an analysis of the predictable components of monthly common stock and bond portfolio returns. Most of the predictability is associated with sensitivity to economic variables in a rational asset pricing model with multiple betas. The stock market risk premimum is the most important for capturing predictable variation of the stock portfolios, while premiums associated with interest rate risks capture predictability of the bond returns. Time variation in the premium for beta risk is more important than changes in the betas.

Sources of risk and expected returns in global equity markets

This paper empirically examines multifactor asset pricing models for the returns and expected returns on eighteen national equity markets. The factors are chosen to measure global economic risks. Although previous studies do not reject the unconditional mean- variance efficiency of a world market portfolio, our evidence indicates that the tests are low in power, and the world market betas do not provide a good explanation of cross-sectional differences in average returns. Multiple beta models provide an improved explanation of the equity returns.

Do Arbitrage Pricing Models Explain the Predictability of Stock Returns

This article studies predictability in U.S. stock returns for multiple investment horizons. The authors measure to what extent predictability is driven by premiums for economywide risk factors, comparing two standard methods for factor selection. They study single-beta models and multiple-beta models. The authors show how to estimate the fraction of the predictability in returns captured by the model simultaneously with the other parameters. Their analysis indicates that the models capture a large fraction of the predictability for all of the investment horizons. The performance of the principal components and the prespecified-factor approaches are broadly similar. Copyright 1995 by University of Chicago Press.

Finite sample properties of the generalized method of moments in tests of conditional asset pricing models

Abstract We develop evidence on the finite sample properties of the Generalized Method of Moments (GMM) in an asset pricing context. The models imply nonlinear, cross-equation restrictions on predictive regressions for security returns. We find that a two-stage GMM approach produces goodness-of-fit statistics that reject the restrictions too often. An iterated GMM approach has superior finite sample properties. The coefficient estimates are approximately unbiased in simpler models, but their asymptotic standard errors are understated. Simple adjustments for the standard errors are partially successful in correcting the bias. In more complex models the coefficients and their standard errors can be highly unreliable. The power of the tests to reject a single-premium model is higher against a two-premium, fixed-beta alternative than against a conditional Capital Asset Pricing Model with time-varying betas.

Testing asset pricing models with changing expectations and an unobservable market portfolio

When the assumption of constant risk premiums is relaxed, financial valuation models may be tested, and risk measures estimated without specifying a market index or state variables. This is accomplished by examining the behavior of conditional expected returns. The approach is developed using a single risk premium asset pricing model as an example and then extended to models with multiple risk premiums. The methodology is illustrated using daily return data on the common stocks of the Dow Jones 30. The tests indicate that these returns are consistent with a single, time-varying risk premium.

Conditional market timing with benchmark investors

This paper tests models of mutual fund market timing that (1) allow the managers utility function to depend on returns in excess of a benchmark; (2) distinguish timing based on lagged, publicly available information variables from timing based on finer information; and (3) simultaneously estimate the parameters which describe the public information environment, the risk aversion and the precision of the funds market timing signal. Using a sample of more than 400 U.S. mutual funds for 1976-94, the estimates imply that mutual funds behave as risk averse, benchmark investors. Conditioning on public information variables improves the model specification, and after controlling for the public information we find no evidence that funds have significant market timing ability.

Fundamental Determinants of National Equity Market Returns: A Perspective on Conditional Asset Pricing

This paper provides a global asset pricing perspective on the debate over the relation between predetermined attributes of common stocks, such as ratios of price-to-book-value, cash-flow, earnings, and other variables to the future returns. Some argue that such variables may be used to find securities that are systematically undervalued by the market, while others argue that the measures are proxies for exposure to underlying economic risk factors. It is not possible to distinguish between these views without explicitly modeling the relation between such attributes and risk factors. We present an empirical framework for attacking the problem at a global level, assuming integrated markets. Our perspective pulls together the traditional academic and practitioner viewpoints on lagged attributes. We present new evidence on the relative importance of risk and mispricing effects, using monthly data for 21 national equity markets. We find that the cross-sectional explanatory power of the lagged attributes is related to both risk and mispricing in the two-factor model than mispricing.

The alpha factor asset pricing model: A parable

Recent empirical studies use the returns of attribute-sorted portfolios of common stocks as if they represent risk factors in an asset pricing model. If the attributes are chosen following an empirically observed relation to the cross-section of stock returns, such portfolios will appear to be useful risk factors, even when the attributes are completely unrelated to risk. We illustrate this result using a parable and argue that the moral of the story is important in practice. ( 1999 Elsevier Science B.V. All rights reserved. JEL classification: C5; G12

The Efficient Use of Conditioning Information in Portfolios

We study the properties of unconditional minimum-variance portfolios in the presence of conditioning information. Such portfolios attain the smallest variance for a given mean among all possible portfolios formed using the conditioning information. We provide explicit solutions for n risky assets, either with or without a riskless asset. Our solutions provide insights into portfolio management problems and issues in conditional asset pricing.

Portfolio Performance Evaluation

This paper provides a review of the methods for measuring portfolio performance and the evidence on the performance of professionally managed investment portfolios. Traditional performance measures, strongly influenced by the Capital Asset Pricing Model of Sharpe (1964), were developed prior to 1990. We discuss some of the properties and important problems associated with these measures. We then review the more recent Conditional Performance Evaluation techniques, designed to allow for expected returns and risks that may vary over time, and thus addressing one major shortcoming of the traditional measures. We also discuss weight-based performance measures and the stochastic discount factor approach. We review the evidence that these newer measures have produced on selectivity and market timing ability for professional managed investment funds. The evidence includes equity style mutual funds, pension funds, asset allocation style funds, fixed income funds and hedge funds.