2. The S&P 500 stock market index measures the total dollar value of a large set of stocks traded on the stock market. The real value of the S&P index, which measures the real value of the wealth represented by that set of stocks, is obtained by dividing the index by a measure of the price level, such as the CPr. (To obtain monthly data on the S&P 500, go to the Web site finance.yahoo.com and get data for ticker symbol: "GSPc.) Using monthly data for the period since 1961, graph the real value of the S&P 500 stock market index. What striking difference do you see in comparing the values in the 1970s with the values in the rest of the period? According to the theory, what effect should the behavior of stock market wealth during the 1970s have had on the national saving rate during that period, relative to the 1960s and 1980s? Look at a graph of the national saving rate for 1960 to the present. Would you say that the prediction is borne out? Discuss.