The Declining Equity Premium: What Role Does Macroeconomic Risk Play?
University of California - Haas School of Business; Centre for Economic Policy Research (CEPR); National Bureau of Economic Research (NBER)
Jessica A. Wachter
University of Pennsylvania - Finance Department; National Bureau of Economic Research (NBER)
Sydney C. Ludvigson
New York University - Department of Economics; National Bureau of Economic Research (NBER)
CEPR Discussion Paper No. 5519
Aggregate stock prices, relative to virtually any indicator of fundamental value, soared to unprecedented levels in the 1990s. Even today, after the market declines since 2000, they remain well above historical norms. Why? We consider one particular explanation: a fall in macroeconomic risk, or the volatility of the aggregate economy. Empirically, we find a strong correlation between low frequency movements in macroeconomic volatility and low frequency movements in the stock market. To model this phenomenon, we estimate a two-state regime switching model for the volatility and mean of consumption growth, and find evidence of a shift to substantially lower consumption volatility at the beginning of the 1990s. We then use these estimates from post-war data to calibrate a rational asset pricing model with regime switches in both the mean and standard deviation of consumption growth. Plausible parameterizations of the model are found to account for a significant portion of the run-up in asset valuation ratios observed in the late 1990s.
Number of Pages in PDF File: 49
Keywords: Equity premium, macroeconomic volatility, stock market boom, regime shifts
JEL Classification: G12
Date posted: June 9, 2006