Search Results
Journal Article
The simple analytics of commodity futures markets: do they stabilize prices? Do they raise welfare?
This paper uses a simple, graphical approach to analyze what happens to commodity prices and economic welfare when futures markets are introduced into an economy. It concludes that these markets do not necessarily make prices more or less stable. It also concludes that, contrary to common belief, whatever happens to commodity prices is not necessarily related to what happens to the economic welfare of market participants: even when futures markets reduce the volatility of prices, some people can be made worse off. These conclusions come from a series of models that differ in their assumptions ...
Report
Assessing specification errors in stochastic discount factor models
In this paper we develop alternative ways to compare asset pricing models when it is understood that their implied stochastic discount factors do not price all portfolios correctly. Unlike comparisons based on chi-squared statistics associated with null hypotheses that models are correct, our measures of model performance do not reward variability of discount factor proxies. One of our measures is designed to exploit fully the implications of arbitrage-free pricing of derivative claims. We demonstrate empirically the usefulness of methods in assessing some alternative stochastic factor models ...
Journal Article
The CAPM debate
This article describes the academic debate about the usefulness of the capital asset pricing model (the CAPM) developed by Sharpe and Lintner. First the article describes the data the model is meant to explain?the historical average returns for various types of assets over long time periods. Then the article develops a version of the CAPM and describes how it measures the risk of investing in particular assets. Finally the article describes the results of competing studies of the model's validity. Included are studies that support the CAPM (Black; Black, Jensen, and Scholes; Fama and ...
Report
The conditional CAPM and the cross-section of expected returns
Most empirical studies of the static CAPM assume that betas remain constant over time and that the return on the value-weighted portfolio of all stocks is a proxy for the return on aggregate wealth. The general consensus is that the static CAPM is unable to explain satisfactorily the cross-section of average returns on stocks. We assume that the CAPM holds in a conditional sense, i.e., betas and the market risk premium vary over time. We include the return on human capital when measuring the return on aggregate wealth. Our specification performs well in explaining the cross-section of average ...
Discussion Paper
Implications of security market data for models of dynamic economies
We show how to use security market data to restrict the admissible region for means and standard deviations of intertemporal marginal rates of substitution (IMRSs) of consumers. Our approach is (i) nonparametric and applies to a rich class of models of dynamic economies; (ii) characterizes the duality between the mean-standard deviation frontier for IMRSs and the familiar mean-standard deviation frontier for asset returns; and (iii) exploits the restriction that IMRSs are positive random variables. The region provides a convenient summary of the sense in which asset market data are anomalous ...
Discussion Paper
Relationship between labor-income risk and average return: empirical evidence from the Japanese stock market
In Japan, as in the United States, stocks that are more sensitive to changes in the monthly growth rate of labor income earn a higher return on average. Whereas the stock-index beta can only explain 2 percent of the cross-sectional variation in the average return on stock portfolios, the stock-index beta and the labor-beta together explain 75 percent of the variation. We find that the labor-beta drives out the size effect but not the book-to-market-price effect that is documented in the literature. We explore the extent to which these results are an artifact of seasonal patterns in ...
Report
Ex-dividend price behavior of common stocks
This study examines common stock prices around ex-dividend dates. Such price data usually contain a mixture of observations?some with and some without arbitrageurs and/or dividend capturers active. Our theory predicts that such mixing will result in some nonlinear relation between percentage price drop and dividend yield?not the commonly assumed linear relation. This prediction and another important prediction of theory are supported empirically. In a variety of tests, marginal price drop is not significantly different from the dividend amount. Thus, over the last several decades, one-for-one ...
Discussion Paper
Ex-day behavior of Japanese stock prices: new insights from new methodology
We study the ex-dividend day behavior of Japanese stock prices for the period 198387. We find that, contrary to previous findings, prices of ex-day stocks drop by nearly the full amount of the dividend. However, ex-day stocks shows an abnormal return. Also, for the many ex-dividend day stocks that also go ex-rights on the same ex-day, we find that the return is on average higher than that for stocks without rights issues. We thus conclude that the ex-day behavior of Japanese stocks are qualitatively similar to that of U.S. stocks.
Working Paper
Momentum Trading, Return Chasing and Predictable Crashes
We combine self-collected historical data from 1867 to 1907 with CRSP data from 1926 to 2012, to examine the risk and return over the past 140 years of one of the most popular mechanical trading strategies ? momentum. We find that momentum has earned abnormally high risk-adjusted returns ?a three factor alpha of 1 percent per month between 1927 and 2012 and 0.5 percent per month between 1867 and 1907 ? both statistically significantly different from zero. However, the momentum strategy also exposed investors to large losses (crashes) during both periods. Momentum crashes were predictable ? ...
Report
The CAPM is alive and well
In empirical studies of the CAPM, it is commonly assumed that, (a) the return to the value-weighted portfolio of all stocks is a reasonable proxy for the return on the market portfolio of all assets in the economy, and (b) betas of assets remain constant over time. Under these assumptions, Fama and French (1992) find that the relation between average return and beta is flat. We argue that these two auxiliary assumptions are not reasonable. We demonstrate that when these assumptions are relaxed, the empirical support for the CAPM is very strong. When human capital is also included in measuring ...