多恩布什宏观经济学第十版原版ppt

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Chapter 1

Introduction Item Item Item Etc.

McGraw-Hill/Irwin Macroeconomics, 10e

© 2008 The McGraw-Hill Companies, Inc., All Rights Reserved. 1-2

What Is Macroeconomics?

Macroeconomics is the study of the behavior of the economy as a whole and the policy measures that the government uses to influence it

Utilizes measures including total output, rates of unemployment and inflation, and exchange ratesShort run: movements in the business cycle Long run: economic growth

Examines the economy in the short and long run

Macroeconomics aggregates the individual markets vs. microeconomics examines the behavior of individual economic units and the determination of prices in individual markets1-3

Macroeconomics In Three Models 1. 2.

Study of macroeconomics is grounded in three models, each appropriate for a particular time periodVery Long Run Model: domain of growth theory focuses on growth of the production capacity of the economy Long Run Model: a snapshot of the very long run model, in which capital and technology are largely fixedThe given level of capital and technology determine the level of potential output Output is fixed, but prices determined by changes in AD

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Short Run Model: business cycle theoriesChanges in AD determine how much of the productive capacity is used and the level of output and unemployment Prices are fixed in this period, but output is variable1-4

Very Long Run Growth

Figure 1-1a illustrates growth of income per person in the U.S. over last century growth of 2-3% per year Growth theory examines how the accumulation of inputs and improvements in technology lead to increased standards of living Rate of saving is a significant determinant of future well being and economic growth.[Insert Fig.1-1 here]

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The Long Run Model

In the long run, the AS curve is vertical and pegged at the potential level of output

[Insert Figure 1-2 here]

Output is determined by the supply side of the economy and its productive capacity The price level is determined by the level of demand relative to the productive capacity of the economy

Conclusion: high rates of inflation are always due to changes in AD in the long run1-6

The Short Run Model

Short run fluctuations in output are largely due to changes in AD

[Insert Figure 1-4 here]

The AS curve is flat in the short run due to fixed/rigid prices, so changes in output are due to changes in AD

Changes in AD in the short run constitute phases of the business cycle

In the short run, AD determines output, and thus unemployment

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The Medium Run

How do we get from the horizontal short run AS curve to the vertical long run AS curve? The medium run AS curve is tilting upwards towards the long run AS curve position

[Insert Figure 1-5 here]

When AD pushes output above the sustainable level, firms increase prices As prices increa

se, the AS curve is no longer pegged at a particular price level1-8

The Phillips Curve

Prices tend to adjust slowly AD drives the economy in the meantime The speed of price adjustment is illustrated by the Phillips curve, which plots the inflation rate against the unemployment rate In the short run, AS curve is relatively flat, and movements in AD drive changes in prices, output, and unemployment

[Insert Figure 1-6 here]

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Growth and GDP

The growth rate of the economy is the rate at which GDP is increasing

Most developed economies grow at a rate of a few percentage points per year

For example, the US real GDP grew at an average rate of 3.4 percent per year from 1960 to 2005

Growth rate is far from smooth (See Figure 1-1b)

1. 2.

Growth in GDP is caused by:Increases in available resources (labor and capital) Increases in the productivity of those resources

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The Business Cycle and the Output Gap

Business cycle is the pattern of expansion and contraction in economic activity about the path of trend growth

[Insert Figure 1-7 here]

Trend path of GDP is the path GDP would take if factors of production were fully utilized

Deviation of output from the trend is referred to as the output gap

Output gap = actual output – potential output Output gap measures the magnitude of cyclical deviations of output from the potential level1-11

[Insert Figure 1-8 here]

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Inflation and the Business Cycle

The inflation rate can be estimated by the percentage change in the consumer price index (CPI)

[Insert Figure 1-9 here]

CPI is a price index that measures the cost of a given basket of goods bought by the average household

If AD is driving the economy, periods of growth are accompanied by increases in prices and inflation, while periods of contraction associated with reduced prices and negative inflation rates1-13