Consumption expenditure: the total demand for consumer goods and services planned investment spending

This chapter develops the aggregate demand-aggregate supply framework, which will allow for an examination of the effects of monetary policy on output and prices.

• This chapter develops the aggregate demand-aggregate supply framework, which will allow for an examination of the effects of monetary policy on output and prices.

Summarize and illustrate the aggregate demand curve and the factors that shift it.

• Summarize and illustrate the aggregate demand curve and the factors that shift it.

• Illustrate and interpret the short-run and long-run aggregate supply curves.

• Illustrate and interpret shifts in the short-run and long-run aggregate supply curves.

• Illustrate and interpret the short-run and long-run equilibria, and the role of the self-correcting mechanism.

Illustrate and interpret the short-run an long-run effects of a shock to aggregate demand.

• Illustrate and interpret the short-run an long-run effects of a shock to aggregate demand.

• Illustrate and interpret the short-run and long-run effects of temporary and permanent supply shocks.

• Explain business cycle fluctuations in major economies during the 2007–2009 financial crisis.

Aggregate demand is made up of four component parts:

• Aggregate demand is made up of four component parts:

• consumption expenditure: the total demand for consumer

• goods and services

• planned investment spending: the total planned spending by business firms on new machines, factories, and other capital goods, plus planned spending on new homes
• government purchases: spending by all levels of government (federal, state, and local) on goods and services
• net exports: the net foreign spending on domestic goods and services

The fact that the aggregate demand curve is downward sloping can also be derived from the quantity theory of money analysis.

• The fact that the aggregate demand curve is downward sloping can also be derived from the quantity theory of money analysis.

• If velocity stays constant, a constant money supply implies constant nominal aggregate spending, and a decrease in the price level is matched with an increase in aggregate demand.

An increase in the money supply shifts AD to the right: holding velocity constant, an increase in the money supply increases the quantity of aggregate demand at each price level.

• An increase in the money supply shifts AD to the right: holding velocity constant, an increase in the money supply increases the quantity of aggregate demand at each price level.

• An increase in spending from any of the components C, I, G, NX, will also shift AD to the right.

Long-run aggregate supply curve:

• Long-run aggregate supply curve:

• Determined by amount of capital and labor and the available technology
• Vertical at the natural rate of output generated by the natural rate of unemployment

• Short-run aggregate supply curve:

• Wages and prices are sticky
• Generates an upward sloping SRAS as firms attempt to take advantage of short-run profitability when price level rises

Shifts in the long run aggregate supply curve

• Shifts in the long run aggregate supply curve

• The long-run aggregate supply curve shifts to the right from when there is:
• An increase in the total amount of capital in the economy
• An increase in the total amount of labor supplied in the economy
• An increase in the available technology, or
• A decline in the natural rate of unemployment
• An opposite movement in these variables shifts the LRAS curve to the left.

There are three factors that can shift the short-run aggregate supply curve:

• There are three factors that can shift the short-run aggregate supply curve:

• Expected inflation
• Price shocks
• A persistent output gap

We can now put the aggregate demand and supply curves together to describe general equilibrium in the economy, when all markets are simultaneously in equilibrium at the point where the quantity of aggregate output demanded equals the quantity of aggregate output supplied.

• We can now put the aggregate demand and supply curves together to describe general equilibrium in the economy, when all markets are simultaneously in equilibrium at the point where the quantity of aggregate output demanded equals the quantity of aggregate output supplied.

Figure 7 illustrates a short-run equilibrium in which the quantity of aggregate output demanded equals the quantity of output supplied.

• Figure 7 illustrates a short-run equilibrium in which the quantity of aggregate output demanded equals the quantity of output supplied.

• In Figure 8, the short-run aggregate demand curve AD and the short-run aggregate supply curve AS intersect at point E with an equilibrium level of aggregate output at and an equilibrium inflation rate at .

Regardless of where output is initially, it returns eventually to the natural rate.

• Regardless of where output is initially, it returns eventually to the natural rate.

• Slow:

• Wages are inflexible, particularly downward
• Need for active government policy

• Rapid:

• Wages and prices are flexible
• Less need for government intervention

With an understanding of the distinction between the short-run and long-run equilibria, you are now ready to analyze what happens when there are demand shocks, shocks that cause the aggregate demand curve to shift.

• With an understanding of the distinction between the short-run and long-run equilibria, you are now ready to analyze what happens when there are demand shocks, shocks that cause the aggregate demand curve to shift.

The aggregate supply curve can shift from temporary supply (price) shocks in which the long-run aggregate supply curve does not shift, or from permanent supply shocks in which the long-run aggregate supply curve does shift.

• The aggregate supply curve can shift from temporary supply (price) shocks in which the long-run aggregate supply curve does not shift, or from permanent supply shocks in which the long-run aggregate supply curve does shift.

Temporary Supply Shocks:

• Temporary Supply Shocks:

• When the temporary shock involves a restriction in supply, we refer to this type of supply shock as a negative (or unfavorable) supply shock, and it results in a rise in commodity prices.
• A temporary positive supply shock shifts the short-run aggregate supply curve downward and to the right, leading initially to a fall in inflation and a rise in output. In the long run, however, output and inflation will be unchanged (holding the aggregate demand curve constant).

A permanent negative supply shock—such as an increase in ill-advised regulations that causes the economy to be less efficient, thereby reducing supply—would decrease potential output and shift the long-run aggregate supply curve to the left.

• A permanent negative supply shock—such as an increase in ill-advised regulations that causes the economy to be less efficient, thereby reducing supply—would decrease potential output and shift the long-run aggregate supply curve to the left.

• Because the permanent supply shock will result in higher prices, there will be an immediate rise in inflation and so the short-run aggregate supply curve will shift up and to the left.

One group of economists, led by Edward Prescott of Arizona State University, believe that business cycle fluctuations result from permanent supply shocks alone and their theory of aggregate economic fluctuations is called real business cycle theory.

• One group of economists, led by Edward Prescott of Arizona State University, believe that business cycle fluctuations result from permanent supply shocks alone and their theory of aggregate economic fluctuations is called real business cycle theory.

Aggregate demand and supply analysis yields the following conclusions:

• Aggregate demand and supply analysis yields the following conclusions:

• A shift in the aggregate demand curve affects output only in the short run and has no effect in the long run.
• A temporary supply shock affects output and inflation only in the short run and has no effect in the long run (holding the aggregate demand curve constant).
• 3. A permanent supply shock affects output and inflation both in the short and the long run.
• 4. The economy has a self-correcting mechanism that returns it to potential output and the natural rate of unemployment over time.

Our aggregate demand and supply analysis also can help us understand business cycle episodes in foreign countries.

• Our aggregate demand and supply analysis also can help us understand business cycle episodes in foreign countries.

• Figure 17 shows the UK Financial Crisis, 2007–2009
• Figure 18 shows China and the Financial Crisis, 2007–2009

The Phillips Curve: the negative relationship between unemployment and inflation.

• The Phillips Curve: the negative relationship between unemployment and inflation.

• The idea behind the Phillips curve is intuitive: When labor markets are tight—that is, the unemployment rate is low—firms may have difficulty hiring qualified workers and may even have a hard time keeping their present employees. Because of the shortage of workers in the labor market, firms will raise wages to attract needed workers and raise their prices at a more rapid rate.

There is no long-run trade-off between unemployment and inflation.

• There is no long-run trade-off between unemployment and inflation.

• There is a short-run trade-off between unemployment and inflation.

• There are two types of Phillips curves, long run and short run.

To complete our aggregate demand and supply model, we need to use our analysis of the Phillips curve to derive a short-run aggregate supply curve, which represents the relationship between the total quantity of output that firms are willing to produce and the inflation rate.

• To complete our aggregate demand and supply model, we need to use our analysis of the Phillips curve to derive a short-run aggregate supply curve, which represents the relationship between the total quantity of output that firms are willing to produce and the inflation rate.

• We can translate the modern Phillips curve into a short-run aggregate supply curve by replacing the unemployment gap (U – Un) with the output gap, the difference between output and potential output (Y – YP).

Okun’s law describes the negative relationship between the unemployment gap and the output gap.

• Okun’s law describes the negative relationship between the unemployment gap and the output gap.

• Okun’s law states that for each percentage point that output is above potential, the unemployment rate is one-half of a percentage point below the natural rate of unemployment. Alternatively, for every percentage point that unemployment is above its natural rate, output is two percentage points below potential output.