Click here to load reader

ISL244E Macroeconomics Problem Session-10 by Research Assistant Serkan Değirmenci D202/16-17.04.2012

  • View
    224

  • Download
    2

Embed Size (px)

Text of ISL244E Macroeconomics Problem Session-10 by Research Assistant Serkan Değirmenci...

  • Slide 1

ISL244E Macroeconomics Problem Session-10 by Research Assistant Serkan Deirmenci D202/16-17.04.2012 Slide 2 Today BLANCHARD (2009), Macroeconomics - Chapter 7: PUTTING ALL MARKETS TOGETHER: THE AS- AD MODEL (btw pages: 157-183) Quick Check (QC): (1-4) (Page: 181) Dig Deeper (DD): (5-11) (Page: 181-183) Slide 3 Chapter-7-QC-1 (Page: 181) 1.Using the information in this chapter, label each of the following statements true, false, or uncertain. Explain briefly. a. The aggregate supply relation implies that an increase in output leads to a decrease in the price level. False. (see page 159) b. The aggregate demand relation slopes down because at a higher price level, consumers wish to purchase fewer goods. False. The AD curve slopes down because an increase in P leads to a fall in M/P, so the nominal interest rate increases, and I and Y fall. (see page 161) c. The natural level of output can be determined by looking at the aggregate supply relation alone. True. (see page 158-160) d. Expansionary monetary policy has no effect on the level of output in the short- run. False. (see page 166-169) e. In the absence of changes in fiscal or monetary policy, the economy will always remain at the natural level of output. False. f. The neutrality of money in the medium run does not mean that monetary policy cannot or should not be used to affect output. True (see Page 169-The Neutrality of Money) g. In the short-run, a reduction in the budget deficit decreases output and decreases the interest rate. True (see Table 7-1) Slide 4 Chapter-7-QC-2 (Page: 181) 2. Supply shocks and the medium run (SIMILAR WITH SECTION 7.6) Consider an economy with output equal to the natural level of output. Now suppose there is an increase in unemployment benefits. (z ) a. Using the model developed in this chapter, show the effects of an increase in unemployment benefits on the position of the AD and AS curves in the short run and in the medium run. b. How will the increase in unemployment benefits affect output and the price level in the short run and in the medium run? ANSWERS: a. SR: short runWS: wage-setting curve MR: medium runPS: price-setting curve WSPSASADISLM SRup no change up no change up MRsame as SR no change up further no change up further Slide 5 Chapter-7-QC-2 (Page: 181) 2.b. YiP SRfallsrises MR falls further rises further Slide 6 Chapter-7-QC-3 (Page: 181) 3.Spending shocks and the medium run Suppose the economy begins with output equal to its natural level. Then, there is a reduction in income taxes. (T ) a. Using the AS-AD model developed in this chapter, show the effects of a reduction in income taxes on the position of the AD, AS, IS, and LM curves in the medium run. b. What happens to output, the interest rate, and the price level in the medium run? What happens to consumption and investment in the medium run? ANSWERS: a. IS shifts right, and LM shifts up. AD shifts right, and AS shifts up. b.Y returns to its unchanged natural level. The interest rate and the price level increase. Slide 7 Chapter-7-QC-4 (Page: 181) 4.The neutrality of money (SEE SECTION 7.4) a. In what sense is money neutral? How is monetary policy useful if money is neutral? b. Fiscal policy, like monetary policy, cannot change the natural level of output. Why then is monetary policy considered neutral but fiscal policy is not? c. Discuss the statement Because neither fiscal nor monetary policy can affect the natural level of output, it follows that, in the medium run, the natural level of output is independent of all government policies. ANSWERS: a.Money is neutral in the sense that the nominal money supply has no effect on output or the interest rate in the medium run. Output returns to its natural level. The interest rate is determined by the position of the IS curve and the natural level of output. Despite the neutrality of money in the medium run, an increase in the money supply will increase output and reduce the interest rate in the short run. Therefore, expansionary monetary policy can be used to speed up the economy's return to the natural level of output when output is low. b.In the medium run, fiscal policy affects the interest rate and investment, so fiscal policy is not considered neutral. c.False. Labor market policies, such as the degree of unemployment insurance, can affect the natural level of output. Slide 8 Chapter-7-DD-5 (Page: 181) 5.The paradox of saving, one last time In chapter problems at the end of Chapter 3 and 5, we examined the paradox of saving in the short run, under different assumptions about the response of investment to output and the interest rate. Here we consider the issue one last time in the context of the AS-AD model. Suppose the economy begins with output equal to its natural level. Then there is a decrease in consumer confidence, as households attempt to increase their saving for a given level of disposable income. a. In AS-AD and IS-LM diagrams, show the effects of the decline in consumer confidence in the short run and the medium run. Explain why curves shift in your diagrams. b. What happens to output, the interest rate, and the price level in the short run? What happens to consumption, investment, and private saving in the short run? Is it possible that the decline in consumer confidence will actually lead to a fall in private saving in the short run? c. Repeat part (b) for the medium run. Is there any paradox of saving in the medium run? Slide 9 Chapter-7-DD-5 (Page: 181) ANSWERS: a. ISLMADAS SRleftdownleftno change MRsame as SRdown furthersame as SRdown b-c. YiP SRfalls MRback to original Y n falls further The short-run change in investment is ambiguous, because the interest rate falls, which tends to increase investment, but output also falls, which tends to reduce investment. In the medium run, investment must rise (as compared to its short-run and original levels), because the interest rate falls but output returns to its original level. Since the budget deficit does not change in this problem, the change in private saving equals the change in investment. It is possible that private saving will fall in the short run, but private saving must rise (above its short-run and original levels) in the medium run. Slide 10 Chapter-7-DD-6 (Page: 182) 6.Suppose that the interest rate has no effect on investment. a. Can you think of a situation in which this may happen? b. What does this imply for the slope of the IS curve? c. What does this imply for the slope of the LM curve? d. What does this imply for the slope of the AD curve? Continue to assume that the interest rate has no effect on investment. Assume that the economy starts at the natural level of output. Suppose there is a shock to the variable z, so that the AS curve shifts up. e. What is the short-run effect on output and the price level? Explain in words. f. What happens to output and the price level over time? Explain in words. Slide 11 Chapter-7-DD-6 (Page: 182) ANSWERS: a. Open answer. Firms may be so pessimistic about sales that they do not want to borrow at any interest rate. b.The IS curve is vertical; the interest rate does not affect equilibrium output. c.The LM curve is unaffected. d.The AD curve is vertical; the price level does not affect equilibrium output. e.The increase in z reduces the natural level of output and shifts the AS curve up. Since the AD curve is vertical, equilibrium output does not change, but the price level increases. Note that output is above its natural level. f.Since Y>Y n, P>P e. Therefore, P e rises and the AS curve shifts up. In fact, the AS curve shifts up forever, and the price level increases forever. Output does not change; it remains above its natural level forever. Slide 12 Chapter-7-DD-7 (Page: 182) 7.You learned in problem 6 (on the liquidity trap) in Chapter 5 that money demand becomes very flat at low interest rates. For this problem, consider the money demand function to be horizontal at a zero nominal interest rate. a. Draw the LM curve. How does the slope of the curve change when the interest rate rises above zero? b. Draw the IS curve. Does the shape of the curve change (necessarily) when the interest rate falls below zero? c. Draw the AD curve? (Hint: From the IS-LM diagram, think about the price level at which the interest rate is zero. How does the AD curve look above this price level? How does the AD curve look below this price level?) d. Draw the AD and AS curves and assume that equilibrium is at a point where output is below the natural level of output and where the interest rate is zero. Suppose the central bank increases the money supply. What will be the effects on output in the short run and in the medium run? Explain in words. Slide 13 Chapter-7-DD-7 (Page: 182) a. The LM has a flat segment at i=0 and then slopes up. b.The IS slopes down as before. There is no flat segment at i=0. Arguably, the IS curve is undefined for nominal interest rates below zero. c. As P falls, M/P rises, and the nominal interest rate falls. Eventually, when P falls far enough, the nominal interest reaches zero. The AD curve slopes down until P reaches the level consistent with i=0. For levels of P below this threshold, the AD curve is vertical. d. There is no effect on output in the short run or the medium run. Since the money stock does not affect the interest rate, it does not affect output. Slide 14 Chapter-7-DD-8 (Page: 182) 8.Supply shocks and demand management Assume that the economy starts at the natural level of output. Now suppose there is an increase in the price of oil. a. In an AS-AD diagram, show what happens to output and the price level in the short run and in the medium run. b. What happens to the unemployment rate in the short run? in the medium run? Suppose the Federal Reserve decides to respond immediately to the increase in the price of oil. In particular, suppose that the Fed wants to prevent the unemployment rate from changing in the short run, afte