This paper examines return predictability of the U.S. stock market using portfolios sorted by size, book-to-market ratio, and industry. A novel panel variance ratio test is proposed and employed to evaluate time-varying return predictability from 1964 to 2011. It is found that the stock returns...

We study return predictability of the Dow Jones Industrial Average indices from 1900 to 2009. We find strong evidence that time-varying return predictability is driven by changing market conditions, consistent with the implications of the adaptive markets hypothesis. During market crashes, no...