Look at the data in Table on the average risk premium of the S&P 500 over T-bills, and the standard deviation of that risk premium. Suppose that the S&P 500 is your risky portfolio.

a. If your risk-aversion coefficient is A = 4 and you believe that the entire 1926–2009 period is representative of future expected performance, what fraction of your portfolio should be allocated to T-bills and what fraction to equity?
b. What if you believe that the 1968–1988 period is representative?
c. What do you conclude upon comparing your answers to (a) and(b)?

Average Annual Returns S&P 500 Portfolio Sharpe Ratio 1-Month T-Bills 3.70 4.02 7.48 2.28 1.04 Standard Deviation Reward to volatility) Probability Period 1926-2009 1989-2009 1968-1988 1947-1967 1926-1946 S&P 500 Portfolio 11.63 10.86 10.91 15.35 9.40 Risk Premium 7.93 6.83 3.44 13.08 8.36 20.81 19.37 16.71 17.66 27.95 .38 .35 .21 74 .30 .92 53 .22 75