Macroeconomics CHAPTER 10. Aggregate Supply and Aggregate Demand

Transcription

1 Macroeconomics CHAPTER 10 Aggregate Supply and Aggregate Demand

2 What you will learn in this chapter: How the aggregate supply curve illustrates the relationship between the aggregate price level and the quantity of aggregate output supplied in the economy Why the aggregate supply curve in the short run is different from the aggregate supply curve in the long run How the aggregate demand curve illustrates the relationship between the aggregate price level and the quantity of aggregate output demanded in the economy How the AS AD model is used to analyze economic fluctuations How monetary policy and fiscal policy can stabilize the economy 2

3 Aggregate Supply The aggregate supply curve shows the relationship between the aggregate price level and the quantity of aggregate output. 3

4 The Short-Run Aggregate Supply Curve The short-run aggregate supply curve is upward-sloping because nominal wages are sticky in the short run:! a higher aggregate price level leads to higher profits and increased aggregate output in the short run. The nominal wage is the dollar amount of the wage paid. 4

5 The Short-Run Aggregate Supply Curve 5

6 Shifts of the Short-Run Aggregate Supply Curve 6

7 Shifts of the Short-Run Aggregate Supply Curve 7

8 Shifts of the Short-Run Aggregate Supply Curve Changes in!commodity prices,!nominal wages, and!productivity lead to changes in producers profits and shift the short-run aggregate supply curve. 8

9 Long-Run Aggregate Supply Curve The long-run aggregate supply curve shows the relationship between the aggregate price level and the quantity of aggregate output supplied that would exist if all prices, including nominal wages, were fully flexible. 9

10 Long-Run Aggregate Supply Curve 10

11 Actual and Potential Output 11

12 Economic Growth Shifts the LRAS Curve Rightward 12

13 From the Short Run to the Long Run Leftward Shift of the Short-run Aggregate Supply Curve 13

14 From the Short Run to the Long Run Rightward Shift of the Short-run Aggregate Supply Curve 14

15 Aggregate Demand The aggregate demand curve shows the relationship between the aggregate price level and the quantity of aggregate output demanded by households, businesses, and the government. 15

16 The Aggregate Demand Curve 16

17 Why Is the Aggregate Demand Curve Downward- Sloping? It is downward-sloping for two reasons:!the first is the wealth effect of a change in the aggregate price level a higher aggregate price level reduces the purchasing power of households wealth and reduces consumer spending.!the second is the interest rate effect of a change in aggregate the price level a higher aggregate price level reduces the purchasing power of households money holdings, leading to a rise in interest rates and a fall in investment spending and consumer spending. 17

18 Shifts of the Aggregate Demand Curve The aggregate demand curve shifts because of!changes in expectations!wealth!the stock of physical capital Policy makers can use fiscal policy and monetary policy to shift the aggregate demand curve. 18

19 Shifts of the Aggregate Demand Curve Rightward Shift 19

20 Shifts of the Aggregate Demand Curve Leftward Shift 20

21 The Multiplier The size of the multiplier, 1/1! MPC, depends on the marginal propensity to consume, MPC: the larger the MPC, the larger the change in real GDP for any given autonomous increase in aggregate spending. 21

22 Total Increase in GDP from $50 Billion Rise in GDP 22

23 The Multiplier 23

24 The AS AD Model The AS-AD model uses the aggregate supply curve and the aggregate demand curve together to analyze economic fluctuations. 24

25 The AS AD Model 25

26 Short-Run Macroeconomic Equilibrium!The economy is in short-run macroeconomic equilibrium when the quantity of aggregate output supplied is equal to the quantity demanded.!the short-run equilibrium aggregate price level is the aggregate price level in the short-run macroeconomic equilibrium.!short-run equilibrium aggregate output is the quantity of aggregate output produced in the short-run macroeconomic equilibrium. 26

27 Shifts of the SRAS Curve Stagflation is the combination of inflation and falling aggregate output. 27

28 Shifts of the SRAS Curve 28

29 Shifts of Aggregate Demand: Short-Run Effects 29

30 Shifts of Aggregate Demand: Short-Run Effects 30

31 Long-Run Macroeconomic Equilibrium The economy is in long-run macroeconomic equilibrium when the point of short-run macroeconomic equilibrium is on the long-run aggregate supply curve. 31

32 Long-Run Macroeconomic Equilibrium 32

33 Short-Run Versus Long-Run Effects of a Negative Recessionary gap 33

34 Short-Run Versus Long-Run Effects of a Positive Demand Shock Inflationary gap 34

35 Self-correcting Mechanism In the long run the economy is self correcting: shocks to aggregate demand do not affect aggregate output in the long run. 35

36 Negative Supply Shocks 36

37 Negative Supply Shocks Negative supply shocks pose a policy dilemma: a policy that stabilizes aggregate output by increasing aggregate demand will lead to inflation, but a policy that stabilizes prices by reducing aggregate demand will deepen the output slump. 37

38 Macroeconomic Policy The high cost in terms of unemployment of a recessionary gap and the future adverse consequences of an inflationary gap " Active stabilization policy, using fiscal or monetary policy to offset demand shocks:! Fiscal policy affects aggregate demand directly through government purchases and indirectly through changes in taxes or government transfers that affect consumer spending.! Monetary policy affects aggregate demand indirectly through changes in the interest rate that affect consumer and investment spending. 38

39 The End of Chapter 10 coming attraction: Chapter 11: Income and Expenditure 39