Robert J. Shiller

Stock Prices and Social Dynamics

The empirical evidence that is widely interpreted as supporting the efficient markets theory in finance actually does not rule out the possibility that changing fashions or fads among investors have an important influence on prices in financial markets. A model of the impact of such fashions on prices is proposed and used in an exploratory data analysis of the aggregate United States Stock Market in the 20th century.

From Efficient Markets Theory to Behavioral Finance

The efficient markets theory reached the height of its dominance in academic circles around the 1970s. Faith in this theory was eroded by a succession of discoveries of anomalies, many in the 1980s, and of evidence of excess volatility of returns. Finance literature in this decade and after suggests a more nuanced view of the value of the efficient markets theory, and, starting in the 1990s, a blossoming of research on behavioral finance. Some important developments in the 1990s and recently include feedback theories, models of the interaction of smart money with ordinary investors, and evidence on obstacles to smart money.

The Volatility of Long-Term Interest Rates and Expectations Models of the Term Structure

Models which represent long-term interest rates as long averages of expected short-term interest rates imply, because of the smoothing implicit in the averaging, that long rates should not be too volatile. The volatility of actual long-term interest rates, as measured by the variance of short-term holding yields on long-term bonds, appears to exceed limits imposed by the models. Such excess volatility implies a kind of forecastability for long rates. Long rates show a slight tendency to fall when they are high relative to short rates rather than rise as predicted by expectations models.

The Term Structure of Interest Rates

Publisher Summary The term structure of interest rates at any time is the function relating interest rate to term. The study of the term structure inquires what market forces are responsible for the varying shapes of the term structure. In its purest form, this study considers only bonds for which default risk can be disregarded, convertibility provisions, call provisions, floating rate provisions, or other special features. Thus, the study of the term structure is regarded as the study of the market price of time over various intervals. The concept of duration is used throughout to simplify mathematical expressions. Continuous compounding is used where possible to avoid arbitrary distinctions based on compounding assumptions. The relations described in this chapter are applied to conventionally defined interest rates or exactly to the continuously compounded McCulloch data. The chapter discusses theories of the term structure. In making plans using the term structure, it is helpful to realize that the term structure on any given date has in it implicit future interest rates called “forward rates.”

Valuation Ratios and the Long-Run Stock Market Outlook

The use of price–earnings ratios and dividend-price ratios as forecasting variables for the stock market is examined using aggregate annual US data 1871 to 2000 and aggregate quarterly data for twelve countries since 1970. Various simple efficient-markets models of financial markets imply that these ratios should be useful in forecasting future dividend growth, future earnings growth, or future productivity growth. We conclude that, overall, the ratios do poorly in forecasting any of these. Rather, the ratios appear to be useful primarily in forecasting future stock price changes, contrary to the simple efficient-markets models. This paper is an update of our earlier paper (1998), to take account of the remarkable behavior of the stock market in the closing years of the twentieth century.

Testing the Random Walk Hypothesis: Power Versus Frequency of Observation

Power functions of tests of the random walk hypothesis versus stationary first order autoregressive alternatives are tabulated for samples of fixed span but various frequencies of observation.

Comparing Wealth Effects: The Stock Market versus the Housing Market

We examine the link between increases in housing wealth, financial wealth, and consumer spending. We rely upon a panel of 14 countries observed annually for various periods during the past 25 years and a panel of U.S. states observed quarterly during the 1980s and 1990s. We impute the aggregate value of owner-occupied housing, the value of financial assets, and measures of aggregate consumption for each of the geographic units over time. We estimate regression models in levels, first differences and in error-correction form, relating consumption to income and wealth measures. We find a statistically significant and rather large effect of housing wealth upon household consumption.

Survey evidence on diffusion of interest and information among investors

Abstract Questionnaire surveys of institutional and individual investors were undertaken to learn about patterns of communications. It was found that direct interpersonal communications are very important in investor decisions. Questions elicited what fraction of investors were unsystematic and allowed themselves to be influenced by word-of-mouth communications or other salient stimuli. Randomly sampled investors were studied as well as investors in stocks whose price had recently increased dramatically. Contagion or epidemic models of financial markets are proposed in which interest in individual stocks is spread by word of mouth. The survey evidence is interpreted as supporting such models.

Rational Expectations and the Dynamic Structure of Macroeconomic Models:A Critical Review

The recent literature on rational expectations in macroeconomic theory is surveyed here with the objective of distilling from the various papers useful suggestions for econometric methodology. The paper is not concerned with the empirical questions with which these models have been associated, but rather with the value and usefulness of the concept of rational expectations. The paper begins with a brief discussion of the theory of martingales as it has been applied to microeconomic theory. Then, the general linear rational expectations model (of which most models discussed in the literature are, in terms of their structure, special cases) is developed arid its properties, advantages and drawbacks discussed. The paper concludes with a discussion of the possibilities for estimation arid application of such linear models.

Stock prices and bond yields: Can their comovements be explained in terms of present value models?

Real stock prices seem to overreact to changes in long-term interest rates. That is, real stock prices drop when long-term interest rates rise (and rise when they fall) more than would be implied by a rational expectations present value model where expectations are based on a vector autoregression. This overreaction is not associated with any overreaction to changes in the short-run inflation rate. Over the last century real stock prices have shown little reaction to changes in inflation rates, and according to the model they should show little reaction. These conclusions were reached from an analysis of annual data in the united states 1871 to 1989 and the united Kingdom 1918 to 1989.