Knowledge that Transforms

Changes in stock prices have substantial explanatory power for U.S. investment, especially for long-term samples, and even in the presence of cash flow variables. The stock market dramatically outperforms a standard q-variable because the market-equity component of this variable is only a rough proxy for stock market value. Although the stock market did not predict accurately after the crash of October 1987, the errors were not statistically significant. Parallel relationships for Canada raise the puzzle that Canadian investment appears to react more to the U.S. stock market than to the Canadian market.

Stambaugh, and especially to Robert Merton for comments on a previous draft. This paper is part of NBER's research program in Financial Markets and Monetary Economics. Any opinions expressed are those of the author not those

The authors of this article present convincing evidence that opening prices differ from closing prices. Their major empirical finding is that returns that are measured from the opening of the market to the next open have higher variance than returns measured from the close of trade to the next close. This result is also found in Amihud and Mendelson (1987), but this article improves on the Amihud-Mendelson study by using a larger sample and by conducting a number of other tests. What is special about opening prices? The authors argue that the higher volatility of open-to-open returns is due to the strategic behavior of the specialist. The specialist sets the opening price in the call auction market that occurs at the open and is allowed to trade from his own account at this price. The authors suggest that in exploiting his monopoly position, the specialist increases the effective bid-ask...

This article examines the linkages between equity markets. The authors present a detailed analysis of the correlations between roughly coincident returns in different equity markets. They also uncover an intriguing fact: The volatility of the London stock market is higher than usual around the time when the NYSE opens. This may support their contagion theory, which argues that traders in one market draw inferences about shocks to share-price fundamentals from observed price movements in other markets. Even price moves which are not generated by fundamentals can therefore affect many markets. The findings raise two basic questions about the comovements in international equity markets. The first is whether there is any reason to expect the correlations across markets to be stable through time. This article emphasizes that returns on the London, New York, and Tokyo markets were more highly correlated around the market break of October 1987 than in other periods....

In this article, we characterize economies in which both cash flows and forward prices follow random walks. We show in the case of geometric random walks that the preferences of the representative investor are of the constant proportional risk-aversion type. We also show the conditions under which spot prices follow random walks and under which the equivalent martingale measure is non-state-dependent.

This article analyzes the behavior of stock return volatility using daily data from 1885 through 1988. The October 1987 stock market crash was unusual in many ways. October 19 was the largest percentage change in market value in over 29,000 days. Stock volatility jumped dramatically during and after the crash. Nevertheless, it returned to lower, more normal levels more quickly than past experience predicted. I use data on implied volatilities from call option prices and estimates of volatility from futures contracts on stock indexes to confirm this result.

Event studies often include cross-sectional regressions of announcement effects on exogenous variables. If the event is voluntary and investors are rational, then standard OLS and GLS estimators are inconsistent. Consistent ML estimators are constructed for a cross-sectional model of horizontal mergers relating announcement effects to exogenous characteristics of firms and industries. The OLS and ML estimates differ dramatically for bidders but not for targets. The evidence suggests that managers of bidders, but not targets, have valuable private information about the potential synergies from proposed mergers.

Results of tests contrasting tax-loss selling with intertemporal information variation as explanations of the January seasonal in stock returns are reported. Closed-end fund shares display the typical size-related January seasonal while their net asset values do not. Interpreting the net asset value return as a proxy for information about underlying assets, this result indicates information variation is not a necessary condition for the January effect in stocks. The share returns at the turn of the year are negatively related to their mean preceding year returns and positively related to the standard deviations of their preceding year returns. These results are consistent with tax-loss selling.