The Return to Capital and the Business Cycle

Real business cycle models have difficulty replicating the volatility of S&P 500 returns. This fact should not be surprising since the RBC theory suggests a measurement of the return of aggregate capital, not stock market returns. We construct a quarterly time series of the after-tax return to business capital. Its volatility is considerably smaller than that of S&P 500 returns. Our benchmark model captures almost 40% of the volatility in the return to capital relative to the volatility of output.