Exercise 2. Analyzing macro events with the IS curve. Suppose the parameters of the IS curve are a = 0, b = -, = 2% and the real interest rare R is initially = 2%. Explain what happens to short-run output (Y) quantitatively and why in each of the following cases (each considered separately): a. R rises from 2% to 4%. b. R falls from 2% to 1%. c. acincreases by 1 percentage point. d. a, decreases by 2 percentage points e. dim decreases by 2 percentage points