Has the Stock Market Become More Efficient in the Long-Run? Evidence from U.S Corporations

Abstract

Using the cointegration model to deal with nonstationary time series, we estimate the long-run relationship between the average stock price and the average dividend. The results from U.S. time series data of 141 years show that the discount rate is lower in the second half of this period, which indicates that stock market becomes more efficient and capital cost becomes lower in the long run. Along with well-documented narrowing of the bid-ask spreads of stocks over time and the growing speed of stock market order fulfillment, market efficiency is further exemplified by lower dividend yields. JEL Classification: G10, C58