Answer to Question 1
a. The initial 5 million decrease in aggregate expenditures will cause real GDP to fall by 5 million. People will respond to this change by cutting consumption spending by 4 million (+5 million 0.80). This second decrease in aggregate expenditures will cause real GDP to fall by 4 million, triggering an additional 3.2 million (+4 million .80) decrease in consumption spending. This will cause successive cuts in income and consumption, each smaller than the previous one.
b. The spending multiplier in this case is 1/(1 0.80) = 5 . This means that real GDP will fall by 5 for every 1 initial change in aggregate expenditures. Therefore, the cumulative effect is that real GDP will fall by 25 million (= 5 million 5).
Answer to Question 2
d