Answer Happy

a. The worksheet labeled Question 1 in the Excel file for this problem set contains quarterly values for the percent deviation from trend in US real GDP (Y), the percent deviation from trend in US real personal consumption expenditures (C), and the percent deviation from trend in US real gross private domestic investment, (1). The data start in the first quarter of 1947 (1947-01-01) and end in the second quarter of 2021 (2021-04-01). Compute and report the standard deviation of the deviations from trend for each series for the entire period for which you have data. The Excel command is = stdev.s(array). b. Compute and report the standard deviation of the deviations from trend for each series for the period 1947-01-01 (first quarter of 1947) through 1983-10-01 (fourth quarter of 1983). Compute and report the standard deviation of the deviations from trend for each series for the period 1984-01-01 (first quarter of 1984) through 2021-04-01 (second quarter of 2021). d. What if any differences in the volatilities of real GDP real consumption, and real investment do you observe when you compare the 1947 - 1983 period with the 1984 - 2021 period? c.

% dev Y % dev C % dev ! 1947-01-01 2.534587 0.429659 -0.06088 1947-04-01 1.217587 1.26465 -9.38544 1947-07-01 -0.04065 0.76855 -13.7172 1947-10-01 0.456067 -0.02106 2.606805 1948-01-01 0.887367 -0.34674 11.02759 1948-04-01 1.454019 -0.01295 15,72716 1948-07-01 0.942749 -0.70294 15.4876 1948-10-01 -0.04425 -0.74759 9.360768 1949-01-01 -2.55116 -1.43139 -8.00182 1949-04-01 -4.0376 -0.76929-23.4604 1949-07-01 -4.18363 -1.40582 -16.692 1949-10-01 -6.22851 -0.82049 -22.9975 1950-01-01 -3.60256 -0.04745 -2.9055 1950-04-01 -1.84803 0.710292 6.052282 1950-07-01 0.681321 4.838582 13.15113 1950-10-01 1.312565 0.901515 24.03295 1951-01-01 1.401959 2.411587 12.29361 1951-04-01 1.874172 -1.32583 13.66615 1951-07-01 2.68981 -1.04859 5.209783 1951-10-01 1.712763 -1.35836 -3.85235 1952-01-01 1.610357 -2.02352 -1.96091 1952-04-01 0.695392 -0.98649 -10.4907 1952-07-01 0.322009 -1.42269 -5.94762 1952-10-01 2.500214 1.126362 0.353995 1953-01-01 3.329906 1.367179 1.798423 1953-04-01 3.129036 1.041128 1.675565