Transcript CH22 短期經濟波動 - NCNU Moodle 課程

Chapter 22
Short-term Economic Fluctuations
(短期經濟波動)
Principle of Economics
National Chi Nan University
Spring 2012
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Learning Objectives
1. Identify the four phases of the business cycle (景氣循環).
2. Explain the primary characteristics of recessions (景氣衰退)
and expansions (景氣擴張).
3. Define potential output, measure the output gap (產出缺
口).
4. Define the natural rate of unemployment (自然失業率) and
relate it to cyclical unemployment (循環性失業).
5. Use Okun's law to analyze the relationship between the
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output gap and cyclical unemployment.
Short-term fluctuations
• Short-term: a period of time sufficiently short that at least
some of the firm’s factors of production are fixed.
• Long-term: a period of time sufficiently length that at all
the firm’s factors of production are variable.
• Even though the economic “climate” (long-term economic
performance) is the ultimate determinant of living
standards, change in the economic “weather” (short-term
economic performance) are also important.
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Business Cycle
• The term for these short-term fluctuations is business cycle,
or cyclical fluctuations (循環性波動).
• Business Cycle: 是一種國家總體性經濟活動的波動，係指
output 或 employment 沿著長期趨勢線，周而復始地由擴張
(expansion) 攀上頂峰 (peak)，然後轉趨衰退 (recession)，
到了谷底 (trough) 又開始步上擴張階段的現象。其持續期間
由一年以上到十年不等。
• Recession / contraction (衰退 / 緊縮): is a period in which
the economy is growing at a rate below normal.
– Depression (蕭條): a particularly severe recession.
– Commonly held to be 2 or more consecutive quarters of
negative GDP growth.
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Business Cycle
• Expansion (擴張): a period in which the economy
is growing at a rate significantly above normal.
Boom (繁榮): a particularly strong expansion.
• A peak (頂峰): is the beginning of a recession.
– High point of the business cycle.
• A trough (谷底): is the end of a recession.
– Low point of the business cycle.
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Business Cycle
(expansion)
(recession)
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Taiwan Business Cycle
Source: 行政院經建會。
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Fluctuations in US Real GDP, 1920-2007
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Fluctuations in US GDP Growth Rate
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Peak
Date
Trough
Date
Duration
(months)
Highest
Unemployment
Rate
Change in
Real GDP
Duration of
Next
Expansion
8/29
3/33
43
24.9%
–28.8%
50 months
5/37
5/38
12
19.0
–5.5
80
2/45
10/45
8
3.9
–8.5
37
11/48
10/49
11
5.9
–1.4
45
7/53
5/54
10
5.5
–1.2
39
8/57
4/58
8
6.8
–1.7
24
4/60
2/61
10
6.7
2.3
106
12/69
11/70
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5.9
0.1
36
11/73
3/75
16
8.5
–1.1
58
1/80
7/80
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7.6
–0.3
12
7/81
11/82
16
9.7
–2.1
92
7/90
3/91
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7.5
–0.9
120
3/01
11/01
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5.8
0.8
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Taming the US recessions, 1929 - 2001
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Real GDP Growth in Five Major Countries
Canada
United Kingdom
Germany
Japan
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Symptoms of Business Cycles
(景氣循環之徵兆)
• Cyclical unemployment is a key indicator of shortterm fluctuations.
• Cyclical unemployment rises sharply during
recessions.
– New labor market entrants have difficulty finding work.
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Fluctuations in US Unemployment Rate
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Fluctuations in US Investment Spending
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Symptoms of Business Cycles
• However, Inflation is not as sharply defined as unemployment
in recessions and expansions.
• Inflation generally decreases during a business cycle.
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影響景氣循環的因素
• 分內在因素與外在因素兩大類。
內在因素: 經濟體內部的不穩定因素。
例如: 對未來的預期心理 (樂觀或悲觀)、貨幣
供給的不穩定、總統或國會大選 … 。
外在因素: 戰爭、國際政治事件、能源危機、重大
科技發明 … …。
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Business Cycle Indicators (景氣循環指標)
Source: 行政院經建會。
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Business Cycle Indicators (景氣循環指標)
• Coincident Indicators (同時指標): 與景氣循環呈現大致類似
的變動狀態的經濟變數。
– Industrial production (工業生產).
– Total sales in manufacturing, wholesale, and retail
(製造業銷售量、躉售批發量、零售量).
– Nonfarm employment (非農業就業量)
– Real after-tax household income (實質稅後家計所得).
• Leading Indicators (領先指標): 領先景氣變動的經濟變數。
例如: 股價指數、製造業存貨量指數、耐久財訂單、工業及
服務業加班工時、貨幣成長率。
• Lagging Indicators (落後指標)。
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Business Cycle Indicators (景氣循環指標)
Source: 行政院經建會。
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Source: 行政院經建會。
Short-Term Economic Fluctuations
• Actually, economic fluctuations are not cyclical at all.
Instead, they are irregular in their length and severity, and
thus are difficult to predict.
• Expansions and recessions usually are not limited to a few
countries but have widespread / global impacts.
– Great Depression (大蕭條) of the 1930s was worldwide.
– US recessions of 1973-1975 and 1981-1982 were widely felt
outside the US.
– East Asian suffered a major slowdown in the late 1990s.
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East Asian Financial Crisis
• 1997年7月2日泰國宣佈放棄釘住美元的匯率制度後，短短數月間，
菲律賓、韓國、馬來西亞、印尼相繼遭受國際投機客的侵襲，馬幣
和泰銖下跌60%，韓國股價下跌50%。
• 1997年10月後: 俄羅斯股市下跌20%，韓圜兌美元的匯率跌至
1737.60∶1，貶值幅度為34%；印尼盾兌美元的匯率跌至14000∶1，
貶值幅度高達85%；新加坡幣下跌61%；日本證券價格三週內下跌
15%；香港經濟呈現負成長，香港證券價格在3天內下降23%。
• 銀行: 南韓14家銀行停業，泰國58家金融公司停業，印尼16家銀行
破產。
• 南韓、菲律賓、泰國之國家金融由 International Monetary Funds
(IMF) 接管。
• 擴散地區: Thailand  Malaysia  Philippines  South Korea 
Indonesia  Singapore  Hong Kong  Japan  Russia 
Czech & Slovak  Ukraine  Brazil
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Potential Output
• Potential output, Y*, is the maximum sustainable
amount of real GDP that an economy can produce.
– Also called full-employment GDP (充分就業下的GDP).
• Actual output (實質產出), Y, does not always equal
potential output.
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Output Gaps
• Output gap (產出缺口) is the difference between
potential output and actual output at a point in time.
Output gap = Y – Y*
– Recessionary gap (緊縮缺口) is a negative output gap;
Y* > Y.
– Expansionary gap (擴張缺口) is a positive output gap;
Y* < Y.
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• Policymakers consider stabilization policies (穩定政策)
when there are output gaps.
– Recessionary gaps mean output and employment are
below their sustainable level.
 Recessionary gap represents wasted resources.
– Expansionary gaps may lead to inflation.
• Recessionary gaps have high unemployment rates.
– Expansionary gaps have low unemployment rates.
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Natural Rate of Unemployment
• The natural rate of unemployment, u*, is the sum of
frictional unemployment (摩擦性失業) and structural
unemployment (結構性失業).
– It is the rate of unemployment when cyclical
unemployment is 0
.
– Occurs when Y = Y*.
– 自然失業率為充分就業 (循環性失業率為零) 時的失業率。
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Natural Rate of Unemployment
• Cyclical unemployment is the difference between
total unemployment, u, and u*.
 u – u* = cyclical unemployment rate.
– Recessionary gaps have u > u* (and Y* > Y).
(Since cyclical unemployment rate is positive, u – u* > 0.)
– Expansionary gaps have u < u* (and Y* < Y).
(Since cyclical unemployment rate is negative, u – u* < 0.)
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US Natural Rate of Unemployment
• From 6.3% in 1979 to 4.8% in 2007.
• Why has the natural rate of unemployment in the US declined?
– Frictional unemployment (摩擦性失業) decreased?
– Structural unemployment (結構性失業) decreased?
– Or both?
• Age structure of the population has changed.
– Share of working age population ages 16 – 24 has declined
from 25% to 15%.
• This group has higher unemployment than older workers.
• Frequent job changes increases frictional unemployment.
• Lower skills means more structural unemployment.
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Okun’s Law
• Okun's law relates the relationship between the output gap
and the cyclic unemployment.
– Okun's law: one percentage point increase in cyclical
unemployment induces a 2 percentage point increase
in the output gap.
– Okun’s law: (Y – Y*) / Y* = – 2 (u – u*).
• Example: suppose the economy begins with 1% cyclical
unemployment and a recessionary gap of 2% of potential GDP
(Y* – Y = 2%).
– If cyclical unemployment increases to 2%, the recessionary
gap increases to 4% of Y*.
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US Output Gap
Year
u
1982 9.7%
1991 6.8
u*
6.1%
5.8
Y* ($B)
$5,584
7,305
1998
2002
5.2
5.2
8,950
10,342
4.5
5.8
Recessionary Gap ($B)
$402
146
(125)
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• In 1982, 1991, and 2002, the economy had a recessionary gap
(Y* > Y). In 1998, there was an expansionary gap.
• The 1982 recessionary gap was $402 billion.
And US population was 230 million in 1982.
– $402 billion/230 million = $1,748 per individual.
– In 2000 dollars it equals $7,000 for a family of four.
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Causes of Short-Term Fluctuations
•
Output gaps arise for two main reasons:
1. Markets require time to reach equilibrium price and
quantity. (市場調整到均衡價格和數量需要時間。)
•
•
Firms change prices infrequently.
(因為廠商不常調整價格  物價具僵固性。)
Quantity produced is not at equilibrium during the
adjustment period. (在價格的調整期間，數量不會馬上
達到均衡。)
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Causes of Short-Term Fluctuations
2. Changes in total spending at preset prices affects
output levels. (總支出改變，若物價不變，會影響產出
水準。)
•
When spending is low, output will be below
potential output.
•
Policy: adjust government spending to close the
output gap.
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Cures for Short-Term Fluctuations
• The economy has self-correcting mechanisms (自我修正機
制).
– Firms will adjust to output gaps.
• If spending is less than potential output, firms will slow
the increase of their prices.
• If spending is more than potential output, firms increase
prices.
– Eventually, prices reach equilibrium and eliminate output
gaps.
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Short-Term Economic Fluctuations
Causes
Short-Term
Economic
Fluctuations
Potential
Output
Symptoms
Business
Cycles
Output Gaps
4 Phases of
Business Cycles
Natural Rate of
Unemployment
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