總體經濟學

Macro economics

授課教師：王泓仁教授

Liang
[挑選日期]
Content
1. Introduction.....................................................................................................................4

1.1. 3Questions...........................................................................................................4

1.2. Economic model...................................................................................................6

2. National incomes: where is comes from & where it goes?...................................7

2.1. Basic concept.......................................................................................................7

2.1.1. 3 markets and 4 players.....................................................................7

2.1.2. Economic activity graph......................................................................8

2.1.3. Some equations from the graph.......................................................8

2.2. How the total production is determined?...................................................9

2.3. How is income distributed?...........................................................................10

2.4. What determine the demand for goods and services? How the output
from production is used?.............................................................................................12

2.4.1. Consumption..........................................................................................12

2.4.2. Investment...........................................................................................13

2.4.3. Government purchase........................................................................14

2.5. How the economy comes into equilibrium?................................................15

2.5.1. Equilibrium in goods and services market....................................15

2.5.2. Equilibrium in financial market........................................................16

2.5.3. Policy analysis: movement along or shift the curve?.................16

3. Money & Inflation..........................................................................................................19

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 3.1. What is Money..................................................................................................19

3.1.1. Function of money...............................................................................19

3.1.2. Some definition of money.................................................................19

3.1.3. Types of money....................................................................................19

3.2. Quantity theory of money.............................................................................21

3.3. Seignrorage.......................................................................................................22

3.4. Inflation and interest rates.........................................................................22

3.5. Cost of inflation...............................................................................................23

3.6. The Money Demand.........................................................................................24

3.6.1. Model 1: 劍橋學派...............................................................................24

3.6.2. Model 2: Keynesian, Liquidity theory of Money.........................25

4. The Open Economy.......................................................................................................25

4.1. The international flows of capital and goods...........................................25

4.2. Saving & investment in a small open economy..........................................27

4.3. 補充：Globle imbalances................................................................................29

4.3.1. 金融風暴的近因....................................................................................29

4.3.2. 發生了甚麼事？....................................................................................30

4.3.3. Implication............................................................................................31

4.3.4. 美國是否依賴中國？.............................................................................31

4.4. Exchange rate...................................................................................................32

4.5. How the real exchange rate is determined?............................................33

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 4.6. The determinants of the nominal exchange rate...................................35

4.7. PPP: purchasing power parity.......................................................................35

5. I.O.U.S.A.........................................................................................................................36

5.1. 主題是甚麼..........................................................................................................36

5.2. 立論基礎..............................................................................................................36

5.2.1. Budget deficit.....................................................................................36

5.2.2. Savings deficit....................................................................................36

5.2.3. Trade deficit.......................................................................................36

5.2.4. Leadership deficit..............................................................................36

5.3. 對台灣的啟示.....................................................................................................37

6. Consumption....................................................................................................................37

6.1. Keynesian consumption function..................................................................37

7. Some news.......................................................................................................................39

7.1. 央行澄清：沒有暗示新台幣升值.....................................................................39

7.2. 台灣生活物價指數今公布 分甲乙丙三類........................................................39

7.3. USA health care..............................................................................................40

1. Introduction

1.1. 3Questions
1. Why do economics grow? Why the growth rate slows down?
甲、 “GDP”, “per capita” ,”overtime”
乙、 To approximate living standard

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 丙、 亞洲公務人員為什麼要貪汙？薪水偏低？
丁、 經濟成長減緩，看每個國家 GDP 翻倍的時間都要增長
戊、 Diminishing marginal return! (在技術被限制的情況下會受到這個法則的限
制)
nominal
己、 real=
price deflator
庚、 GDP and GNP,前者包括外商在台的利潤，後者包括大陸台商的利潤。交集
是台灣台商的利潤
辛、 GDP vs CPI, 前者包括政府買的軍購，後者卻是典型都市消費者會買的東西
2. Why do economies have cycles?

GDP

Time
甲、

乙、 經濟長期是成長的，短期有循環(cycle)

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 丙、 台灣的失業率：維持在 5.8%。美國現況：10%左右，經濟大蕭條 25%

丁、 Definition:

U nemployment rate=willing ¿ work but unable ¿ find jobs ¿

people looking for jobs

戊、 Discouraged worker，覺得景氣太糟市場太壞，沒有在找工作的人
3. What can policies do?
甲、 Government policy 分兩類
i. Fiscal policy 改變 G or T
ii. Monetary policy
乙、 消費券屬於哪種？消費券是央行印的，但是既非兩種政策之一，也可說兩種
政策兼而有之。

1.2. Economic model

 Made of symbols and equations, illustrate the relationship between key
economic variables
 Precise arguments/assumptions:

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 Exogenous variables1, endogenous variable2

Exogenous Endogenous
Model
variables variable

1
Exogenous variables:外生變數(由政策所決定，不關心這個變數如何來的)

2
endogenous variable:內生變數(經過模型之後會產生的結果)

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2. National incomes: where is comes from & where it goes?

2.1. Basic concept

2.1.1. 3 markets and 4 players

goods
and
services

3
markets

labor money
markets markets

firms

4
foreigners household
players

government

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＊：以 house hold 而不以個人為單位，因為經濟活動的 decision 都是以家計為單位
（比如說要買房子，通常不會為了個人因素買，而是為了全家人去買）

2.1.2. Economic activity graph

Assume no international trade.

Income (Y): Factor market

labor income ( 勞動要素收入 )
Factor payment (Y)
capital income ( 資本收入 )
economic profit ( 企業家精神收入 )

Financial market

Private saving
Public saving Deficit

Household Government Firms

Tax (T)

Government purchase (G)

Investment (I)

Consumption (C)
Goods & Services market Output (Y)

箭頭代表錢的流向

公司的錢都是股東的！錢最後還是跑到 household

此處 Investment 的定義為 capital investment。由 firms 購入資本，投入 Goods &

Services market

2.1.3. Some equations from the graph

等式有兩種要注意：

 Definition：用來表示定義的恆等式(identity)
 Equilibrium：用來表示條件的關係式

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Goods market:

Y =C + I + G

Factor market:

Y= labor income+ capital income + economic profit

Government:

Deficit=G-T or. T=G-deficit

Financial market:

Private saving+ public saving=I or. Private saving= deficit+ I

What determinate level of production? How the market distributes the income
to the factor owners?

2.2. How the total production is determined?

Determined by production function:

Y =F ( k , L )

1. Factors of production: k, L
2. Production technology: F(, )3

Here, we assume: k =ḱ (with a bar means it’s fixed), L= Ĺ, in S0 , Y =F ( ḱ , Ĺ )=Ý

Price k L implication
Short run Fixed k =ḱ L= Ĺ May have unemployment
(<3 years) (business cycle)
Long run Flexibl k =ḱ L= Ĺ Full employment4, no
(3~5 years) e factor accumulation
Very long Flexibl k may L= Ĺ, may Full employment, no
run e change over change over factor accumulation

3
生產函數本身就隱含了生產技術。舉例來說，比較 2k+L 與 3k+L 兩函數，同樣單位的要素，
由後者的生產函數可以得到更高產出。表示後者有更精良的技術。

4
仍然有摩擦性失業

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 (>5 years) time time (economic growth)

2.3. How is income distributed?

The following theory we will introduce is called neoclassical theory of
distribution. It is based on classical idea that prices adjust to balance supply
and demand, together with the idea that demand for each factors of production
depends on the marginal productivity of that factor.

Y =F ( k , L )

提供要素的代價

 K: obtain rent
 L: wage
 Firm(企業家): profit

NOTATION:

Output price P
Revenue P*Y
Wage rate w
Labor cost(wage bill) w*L
Capital rental rate R
Capital cost R*k
Profit =revenue-cost
=PY-(wL-Rk)
ASSUMPTIONS:

1. F(,) has a CRTS5 technology.

2. Competitive market: w, P, R are given to the firm. (they are fixed)
3. The firm chooses the k and L to maximize profit.

By the assumption 1 and 2, the cost is CRTS, and the income is CRTS, too.
Thus, the profit is also CRTS. However, the economic has equilibrium, which

5
CRTS: constant return to scale. We say a production function F(k, L) is CRTS iff
F(ak,aL)=aF(k,L), for positive scalar a.

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implies that economic profit must be zero. Otherwise, a profit maximizing firm
can earn infinite economic profit by inputting as much factor as it can.

By assumption 3:

max π=P ⋅ F ( k , L )−wL−Rk solution :k ¿ ⋅ L¿ ⇒ profit ¿

k,L

∂ F (k , L) ∂π ∂ F (k , L) ∂π w
MPk = ≡ F k =0 MPL= ≡ F L =0F L =
∂k ∂k ∂L ∂L P
P (real wage rate/marginal product of labor)
P ⋅ Fk −R=0 R=P ⋅ F k ∨. F k =
R
Q: how is the amount of output(Y)6 distributed to the factor markets?

A: factors are paid according to their marginal contribution to the production

process:

w R
labor : =MPLcapital : =MPK
P P

So,

w R
Y= ⋅ L+ ⋅k + 0 F ( k , L )=MPL ⋅ L+ MPk ⋅ k
P P

w
⋅L
p 2
labor share=factor product ¿ L ¿ = ≈
out put Y 3

R
⋅L
¿ p 1
capital share=factor product ¿ capital obtain = ≈
out put Y 3

(實際的數字是實證資料)大陸的 capital share>1/3

6
In this course, output and income is same thing. It depends on which perspective you
take.

頁 12
Q:有沒有甚麼樣的方程式，有著規模報酬的性質，又有邊際報酬遞減的性質7，適合當
作生產函數來用？

A:Cobb-Douglas function

方程式 2-1 Cobb-Douglas function

F ( k , L )= Ak α L1−α , 0<α < 1

在人口統計學中，出生率(crude birth rate, CBR)的定義是每年、每一千人當中

的新生人口數。某年出生率的數值扣掉死亡率的數值，即為該年的人口自然增長率
(「自然」意謂不含移民人口)。另外一個生育率指標也經常用到：總和生育率(total
fertility rate, TFR)－即在育齡期間（國際傳統上一般以 15 歲至 44 歲或 49 歲為
準）,每個婦女平均的生育子女數。一般來說，總和生育率是一個更好的生育率指標，
因為它不像自然生育率那樣，容易被人口的年齡分佈所影響。一般來講如果總和生育
率小於 2.1(對已發展國家來說)，新生人口是不足以代替生育婦女和其伴侶數量的。

2.4. What determine the demand for goods and services? How the output
from production is used?
Y =C + I + G+ NX

Assume closed economy, NX=0

C I G
Y= + +
household firms governments

2.4.1. Consumption
佔 Y 成分最大的是 C （2/3 of GDP）
（但以變動率來看(在台灣)使 Y 變化最大的成分來講 NX 最大）

Income: Y

Disposable income8: Y-T (can be used in consumption and saving)

7
Return to scale 和 diminishing marginal return 是否衝突？Return to scale 指的是「所有種
類」的要素投入皆倍數增加，報酬也會等倍增加；diminishing marginal return 指的是固定其
他要素投入，「只變動一種」要素，會有報酬遞減的現象

8
Disposable income:可支配所得

頁 13
C=c ( Y −T )

可支配所得的函數，c 是個函數

Definition 2-1 Marginal propensity to consume

∂C
MPC ≡ ,0< MPC <1
∂ ( Y −T )

Marginal propensity to consume: the amount on consumption for each dollar

increase in disposable income.

台灣消費券成功的原因跟商家的促銷行動有關。使得消費券發出的時候，人們有更大
的誘因去花錢（增加 MPC）

C=a+ b ( Y −T )

其中 a>0,是 Autonomous consumption9 ，b 是 MPC

2.4.2. Investment
大約佔 15%的 GDP

Definition 2-2 Investment

Money spent on goods that provide services or returns in the future.

不是一般買基金買股票那種投資！而是購入固定資產

Giving up consumption today in exchange for future consumption.

Investment 的重要動機：risk averse! 故有 Consumption smoothing 的行為

interest rate is key issue. 利率高的時候不投資!!（銀行利率高要趕快存錢？那是

儲蓄不是投資！）

兩種想法：

1. 買機器要借錢，利率高不借錢
2. 利率高的時候，折現之後保有錢比較有價值

9
Autonomous consumption:自發性消費

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Example 2-1

Have $10 today. Buy a machine which returns $x each year for 10 years.

define

x x x
Ω ( r )=−10+ + +…+
1+r (1+ r ) 2
( 1+r )10

Ω ( r ) >0才會去投資

net gross
Interest rate r 1+r
Definition 2-3 nominal interest rate

¿ P Q
1+i nominal =money returned ¿ next year = t +1 t +1
money invested today Pt Q t

Definition 2-4 real interest rate

¿ Q
1+r real =quantitiy of goods returned ¿ next year = t +1
quantitiy of goods invested today Qt

方程式 2-2 fisher equation

Pt +1 Q t+1
P Q
1+i nominal = t+1 t +1 =
Pt Q t ( Pt
)( Qt
inflation rate real interest
)
¿ ( 1+ π )( 1+r )¿ 1+ π +r + πr≈ 1+ π +r

Thus we can get:

⇒ i nominal =π +r real

2.4.3. Government purchase

觀念澄清：Government purchase 不是 Government spending!!

Government spending 包含 Government purchase & transfer payment(轉移性支出)

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Government purchase 必須是實質用於購買商品或服務的行為（如國防，建設…等
等）；反之，轉移性支出是如健保勞保等等，從人民收錢，又把錢丟給人民，對我們
關心的 GDP 不造成影響。

Note: 通常 government purchase 和 tax 都視為外生變數，當作固定的值，記為 Ǵ , T́ 。

我們關心這些政策變數的變化會如何影響 C I r

2.5. How the economy comes into equilibrium?

Equilibrium of two markets

Supply Demand
A:Goods and Y C, I, G
services
B:Financial markets Loanable funds(saving) Loanable funds(investment)
To show that

1. Equilibrium in A implies equilibrium in B, and vice versa.

2. Interest rate plays an important role.

2.5.1. Equilibrium in goods and services market

Y =C + I + G

And get in detail of each component, we can get…

Y =F ( ḱ , Ĺ )=Ý C=c ( Ý −T́ )=Ć I =I ( r )G=Ǵ

Combine those result,

Y = Ć+ I ( r )+ Ǵ
supply demand

So, adjustment in the interest rate ensures equilibrium in the market.

If supply> demand
produce too much
no needs to do investment

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r↓i↑
demand↑ until demand=supply

2.5.2. Equilibrium in financial market

Y −T −C + T −G
Y =C + I + G⇒ Y −C−G=I
⇒ (⏟
private saving ) ( public saving )
=I

national saving

S I
⇒ = ⇒ financial market eqilibrium
supply for loanable funds demand for loanable funds

S=S*
r

r=r1

r=r*

r=r2
I(r)

S.I.

S=Y −C−G ⇒S= ŚY =F ( ḱ , Ĺ )=Ý C=ĆG=Ǵ

At r1: fund supply> fund demand, r↓ until r=r*

如何看一個國家有沒有多餘的資金？就看超額準備率。通常超額準備率都會在 0.1%內
波動，但在 2008 年的時候，超額準備率竟然有 0.6%，顯示國內的可貸資金供給過多。

2.5.3. Policy analysis: movement along or shift the curve?

 If caused by change in exogenous variable shift the curve
 If caused by change in endogenous variable movement along the curve
 What is endogenous variable on the graph? The variable on the axes!

Example 2-2

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y=f ( x , z )=10−2 x +5 z

Can easily be seen from the graph

We concern about:

1. Which curve is affected?

2. Movement-along or shift?10
3. In which direction?

Example 2-3 On fiscal policy

S’ bar S bar
r

I(r)
ΔG

S,I
ΔI

Equilibrium : Ś=I ( r ) Ś ≡Y −C−G=Ý −c ( Ý −T́ ) −Ǵ I ≡ I ( r )

這裡假設 Y 是不會變動的

10
只描述往左或往右，而不要描述往上或往下。雖然對於負斜率的線，往左等於往下，但是對
正斜率的線來說往左卻是往上。必須要有統一的講法

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所以政府想要利用財政政策(fiscal policy)增加開銷時，會在可貸資金市場和民間部門
競爭，於是資金價格(利率)上升。

由於假設 Y 不會變動，此時由圖可見

| ΔI|=| ΔG|

政府資金的增加使民間部門的投資完全減少！稱做 100% crowding out11。

Example 2-4 Animal spirit

突然投資的爆增，無法用 model 來解釋。

投資暴增使得 r↑，I 還是不動，因為可貸資金的供給是個定數

S
r

I’

S,I

3. Money & Inflation12

Definition 3-5 inflation

Inflation: the phenomenon of continued increase in the price level.

11
crowding out effect:指政府增加開銷使得民間部門的投資減少的情形，由於本例是極端的例
子，假設了 Y 不隨 G 的改變而影響，所以才會政府開銷的增加完全等於投資的減少。若 S 是正
斜率，則 crowding out effect 不會那麼嚴重。crowding out effect 是非常壞的現象，要盡量
避免

12
傅利曼(M. Friedman)最知名的理論，是他提出的貨幣供給作為決定生產價值基準的因素，通
貨膨脹在根本上源自於貨幣供給量的主張(inflation is a monetary phenomenon)，是以本章把
money 和 inflation 提在一起。(貨幣主義)

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Definition 3-6 price level

GDP deflector

CPI: Measuring the price of a standard group of goods meant to represent the
typical market basket of a typical urban consumer.

P t+1 −P t
π t +1=
Pt

3.1. What is Money

3.1.1. Function of money

1. Medium of exchange
2. Store of value
3. Unit of account

3.1.2. Some definition of money

demand
deposit sving
M2
deposit
M1 bills
currency
coins

3.1.3. Types of money

Commodity money Fiat money
Definitio has intrinsic value no intrinsic value
n
Example Gold, silver Dollar bill
Property 1. Universally Value is given by the government
accepted
2. Durable

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 Pros Avoid sustained inflation Supply is under the government’s control
Cons Inconvenient to verify 13
inflation

This note is legal tender for all debts, public or private.

FYI 3-1綠野仙蹤(The Wonderful Wizard of Oz)和貨幣供給十分有關係

故事中… 寓意
Doris 非常鄉村姑娘的名字
Tin man 中西部工廠的勞工
Straw man 中西部的農夫
Lion 當時一個懦弱的總統候選人
走在黃金色的道路上 代表是在金本位的制度
要到東方找綠色的城堡的巫師 東方是華盛頓 DC，綠色代表錢，巫師是總統
最後丟了一個銀幣把主角們送回去 倡議必須放棄金本位回到銀本位
故事的作者是中西部的一個財金記者

FYI 3-2 Yap island

雅浦島本地並不出產製造石幣用的石灰石，當地人只有到帛琉等地將石材用獨木舟等
運回自己的家鄉，再將其進一步加工成石幣。因而許多石頭在渡海過程中就石沉大海，
能流傳下來的很稀少。根據當地人的傳說，5 百至 6 百年前一支探險隊到達帛琉並帶
回了圓孔石灰石，因其非常珍貴，當地人便將其當做以物換物的中介。20 世紀之後，

13
常常因為不該採的時候採到金礦，要錢的時候偏偏採不到礦。黃金或白銀開採不足的時候，
會發生物價下跌。例如工業革命以後，人口與經濟的增長大過於黃金的增長。

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隨著外來經濟的入侵，當地人不再像之前那麼依賴石幣進行貿易。第二次世界大戰中，
駐紮此地的日本守軍將其打碎鋪路，毀壞了不少石幣。如今，由於旅遊業的發展和經
濟全球化，當地人更願意用美元等貨幣同遊客交易，使用石幣的傳統漸漸消失。

3.2. Quantity theory of money

MV =PY

M: money stock currency

V: velocity, the times the entire money stock change hand in a given period of
time.

Transaction: water
2
Transaction: milk
2

M=4 Transaction: book

Transaction: bread 2

2
M=4 V=2 ( 每一塊錢都轉手兩次 ) P=2 Y=4

由上圖可知，要支持經濟社會 100 億的交易不需要真的發行 100 億的貨幣。因為一張

貨幣可以轉手好幾次。

MV =PY

1 1 1 1
⇒ ln M + ln V =ln P+ln Y ⇒ dM + dV = dP+ dY
M V P Y

M t+1 −M t
Mt π

⏞ +%ΔV =%ΔP
⇒ %ΔM ⏞ +%ΔY

Usually, V is constant.

%ΔV =0

頁 22
Therefore,

%ΔM =π +%ΔY … ( ¿ )

If, in the short run that Y =Ý , then

%ΔM =π

Shows that inflation is a monetary phenomenon!

Note 1: In gold standard, usually M is fixed. So,

π=−%ΔY

Note 2: If %ΔM >%ΔY ⇒ π >0, inflation.

Note 3: If want π=0 , the growth rate of money must be equal to the economic
growth rate.

3.3. Seignrorage
Definition 3-7 Seignrorage

Seignrorage(鑄幣稅): The revenue of the government from printing money.

(Government’s power of having “inflation tax.”)

 Finance government debt14

 Borrow from the public
 Printing money

Print the money

 ⇒ M ↑⇒ π ↑
 Make existing money worth less… (not worthless!)
 Take away the purchasing power from the public.
 Call this “inflation tax”

3.4. Inflation and interest rates

台幣有升值壓力，詳見：11.1

14
Let Government purchase: 100%: tax 80%, debt 20%.

頁 23
Definition 3-8 Fisher effect

i=r + π

參照：方程式 2 -2 fisher equation

Fisher effect: Increases in π usually lead to increases in i. (r is usually

determined by real variable)

FYI 3-3 Hyperinflation

The inflation in the Weimar Republic

was a period of hyperinflation in
Germany (the Weimar Republic)
during 1921-1923.

史上最可怕的通膨，最後引起希特勒的
崛起。

3.5. Cost of inflation

通膨會造成許多不方便

 Cost of expected inflation

1. Shoe leather cost: 因為通膨
的影響，要常常變動資產的配置去賺取利息。會造成許多摩擦力。(鞋皮的隱
喻因為要常跑銀行而磨破鞋子)
2. Menu cost: transaction cost!
3. Wage, tax, etc. are usually not indexed to the inflation
 Cost of hyperinflation
1. Extremely large transaction cost
2. Huge degree of uncertainty
甲、 Relative price variability
乙、 Redistribution effect
3. Social instability：世界各國的央行都把物價穩定視為最重要的目標之一，
原因於此！

頁 24
The cost of holding money:

Put in pocket: get – π

Put in bank: get r (>0)

So, the return of putting money in pocket

(−π )−r=−( π +r )=−i

So, the cost of holding money is the nominal interest rate.

3.6. The Money Demand

How much currency+ demand deposit you want to keep? Vs saving deposit(i)

3.6.1. Model 1: 劍橋學派

why keep money? most likely for transaction purpose

受到 income, the general price level,交易的次數有關

So,

M d ≝ k ⋅Y ⋅ P

方程式 3-3

Md
⇒ ( )
P
⏟
=kY

real money demand

Ms: nominal money supply. In equilibrium, M d =M s=M

So, in equilibrium (money market equilibrium condition)

eq eq
d
M ¿⏞ M ≝ kYP⇒ M ¿⏞ kYP

方程式 3-4

頁 25
 M
⇒ (⏟
P)
=kY

real money balance( RMB)

(The quantity theory of money)

注意方程式 3 -3 和方程式 3 -4 長得很像，但意義不同。前者是定義貨幣供給的函數；

後者描述在貨幣市場達到均衡狀態時的情形。

凱因斯覺得 P 不應該上漲的時候貨幣需求也上漲

3.6.2. Model 2: Keynesian, Liquidity theory of Money

Model 1 implies that when P keep rising, Md ↑ ,too. That is not realistic.

Classical dichotomy

M d
( )
P
=L¿

In equilibrium, M d =M s=M

So,

( MP )=L ( i, Y )
4. The Open Economy

4.1. The international flows of capital and goods

“open”: trade with other countries

The “openness” of an economy is measured by

Exports+ Imports
GDP

Closed:

Y =C + I + G

頁 26
Open: (d for domestic, f for foreign)

Y =C d + I d + Gd + EXC=C d +C f ⇒C d=C−C f Y = ( C−C f ) + ( I −I f ) + ( G−Gf ) + EX

C f + I f +G f )
¿ C+ I +G+ EX−(⏟
ℑ

So,

Y =C + I + G+ ⏟
EX−ℑ
Y =C + I + G+ NX
NX

Y −C−G=I + NX S=I + NX⇒ S−I =NX

當國內的投資和儲蓄不相等時，會進出口國外的財貨來補足

In closed economy: S has to equal to I. In open economy, the difference can be

financed by foreign goods.

NX
trade balance

NX>0 NX=0 NX<0

trade surplus trade balanced trade deficit

Trade account=current account

S> I ⇒ NX >0 Trade surplus (current account(CA) surplus): Save more than is
needed for domestic investment. The excess amount is lent to foreigner. 
capital outflowcapital account(KA) deficit15

假設有個只有兩個國家的世界

圖表 4-1用兩個國家的世界說明國際貿易

Country A Country B
S−I =NX >0 S−I =NX <0

15
只要是錢流出去，就是 capital deficit。注意 current account 和 capital account 的 surplus
和 deficit 是互補的。BOA(balance of account)=CA+KA=0

頁 27
 ( Y −C−G )−I =NX > 0 ( Y −C−G )−I =NX < 0
Lent to country B (capital account Get money from A(capital account
deficit) surplus)
(current account surplus) Use the money to buy things from A.
(current account deficit)
和金融海嘯有點關係，中國大陸因為法令限制儲蓄很高而投資不振。因此出口旺盛，
借錢給美國(買美國債券)，使得美國的利率變得很低。

4.2. Saving & investment in a small open economy

Assumption:

1. Perfect capital mobility(資金可以任意移動，而不會有央行打電話喝咖啡)

2. Small economy
3. r =r w , fixed(since the small economy assumption). r w is determined by world
saving investment.

Trade surplus, S-I=NX>0 S=Y-C-G

r

r=rw

r=rw
Trade deficit S-I=NX<0
I=I(r)

S,I

Perform policy analysis16

1. increase government purchase, G↑

甲、 national saving↓S shift to S’
乙、 Since r=rw is fixed, so the equilibrium changes from A to B
丙、 At B, S<INX<0trade deficit.
G>T budget defcit. So, budget deficit leads to trade deficit.
twin deficit!

16
下面舉的前兩例 G↑和 T↓，都屬於擴張性財政政策(expansionary fiscal policy)

頁 28
 S’ S=Y-C-G
r

A
r=r0
B
I=I(r)

S,I
丁、

2. Tax cut, T↓
甲、 減稅的話，總儲蓄會上升 or 下降？直覺上政府退稅 100 元，就算花掉了 60
元，還有 40 元可以儲蓄，但…
T↓Y-T↑C=c(Y-T) ↑Y-C-G↓總儲蓄是下降的
其實上述直覺描述的是私部門的儲蓄(private saving)+40，公部門的儲蓄
(public saving)其實少掉了 100 元的稅金。於是總儲蓄還是下降的

S’ S=Y-C-G
r

A
r=r0
B
I=I(r)

S,I
乙、

3. Foreign government increase purchase, G f ↑

甲、 For G f ↑ ⇒ r w ↑
w
乙、 At r 1 , S > I ⇒ NX >0

頁 29
 S=Y-C-G
r Trade surplus

S
r=r0
I

r=r0

I=I(r)

S,I
丙、

丁、 就像當初伊拉克戰爭時，國外政府增加支出，買了很多台灣的電子設備，還
有沙漠中的裝備。

4.3. 補充：Globle imbalances

金融海嘯的遠因

全球化與全球失衡

全球化之後富有的國家會輸出資金！

二三十年前，人們對資本市場全球化的預測

開發中國家： 富有國家
高投資率：工資低，但可以得到先進技術 低投資率
高成長低儲蓄； 高儲蓄
大量貿易赤字(資金流入)； 貿易出超資金流出
但與現在觀察不同資金從開方中國家流向富有國家！
主要債權國與債務國的比例佔全世界其實很低

 為什麼？發生了什麼事？
 此現象會持續下去嗎？
 各國能做什麼事？

4.3.1. 金融風暴的近因
次級房貸泡沫化

頁 30
葛林斯班用降息解決網路泡沫，但低利政策造成後來房市的泡沫

4.3.2. 發生了甚麼事？
全球儲蓄過剩(globle saving glut)， 新興國家儲蓄很多

S
⏟ −I = NX
⏟
China China >0
中國國內儲蓄過剩 對美國出超
投資太少

美國： S < I

新興國家的金融仲介出問題

美國一直處於負債狀況，而且逐年上升。石油輸出國資金流入

參考圖表 4 -1 用兩個國家的世界說明國際貿易

4.3.2.1. 全球儲蓄過剩(globle saving glut)

 為什麼新興國家儲蓄那麼多？
 民眾(私部門儲蓄)
 對於未來的不確定感，增加預防性儲蓄(醫療照護)
 對資本移動的管制，使投資機會受限
 國家(公部門儲蓄)
 對未來的不確定感，累積外匯以因應金融風暴及突來的變動17(被亞洲金
融風暴嚇到，必須多準備外匯以防投機客攻擊貨幣)
 新興產油國：累積大量賣油盈餘

4.3.2.2. 金融仲介與投資
新興家金融仲介出問題，限制世界對新興國家的投資。

雖然新興國家的投資很多（多過已開發國家；例：中國），但仍低於儲蓄；為什麼？

 光有技術及低工資仍不夠；財產權是個問題。
 金融中介無效率；風險無法順利移轉。

17
亞洲金融風暴：投機客預期泰銖會下跌，於是大量賣出泰銖。泰國央行為了預防貶值，必須
使用大量外匯(美元)，買回泰銖。但最後外匯用完的一天，泰銖還是大幅貶值了，於是引起金
融風暴

頁 31
4.3.2.3. 對美國資產的偏好
為什麼是對美國(而非歐盟)產生大量赤字？

 美國的低儲蓄率及預算赤字；
 對美國資產的偏好；
 低風險、高流動性

對美國資產有信心而進行投資，使美國外債不斷上升，但這終將使投資人信心喪失。
除非：美國生產力不斷上升

FYI 4-4五隻小豬(PIIGS)

黑豬五國（英語：PIIGS），亦作歐豬五國或五小豬國，是國際債券分析家、學者和
國際經濟界媒體對歐洲五個較弱的經濟體的貶稱。這個稱呼涵蓋葡萄牙
（Portugal）、義大利（Italy）、愛爾蘭（Ireland）、希臘（Greece）、西班牙
（Spain），特別指各國的主權債券市場。 黑豬五國最初稱為黑豬四國 "PIGS", 其
中"I"指義大利，後來加入了愛爾蘭。最初的這四個南歐國家文化傳統、地理位置比較
接近，加上近年同樣面對財政赤字的愛爾蘭共和國（地理上不屬南歐，但位置較接
近。），最近幾年經濟增長停滯不前，失業率高，又有較高的財政赤字。 鑒於情況近
似，才有財經人士把五國並列一起。

4.3.3. Implication
 美國和全世界的實質利率都很低
 資產市場的過熱；

4.3.4. 美國是否依賴中國？
若外國(特別是中國)的資金停止流入美國；美元走弱、通膨、美國利率提高，造成進一
步需求的衰退，中國也怕這種事情發生。兩相依賴！

4.3.4.1. 美國能做甚麼？
 美國的問題：國家總儲蓄太低
 貨幣政策對策：升息以鼓勵私部門處續，並遏止房屋價格的飆漲，也許可因此避
免金融風暴的發生，現在升息時機已過。
 財政政策對策(公儲蓄=稅收-支出)：
 減少支出：最大宗是老人醫療照護：難(因為參議員都是老人)。

頁 32
  增加稅收：時機已過。

4.3.4.2. 中國能做甚麼？
 要調整不平衡，中國的淨出口勢必下降：NX=S-I，表示投資上升或儲蓄下降。
 投資上升：不太可能在上升。
 降低私部門儲蓄：經濟及社會環境好了以後，自然會下降
 降低公部門儲蓄：可透過增加教育醫療公共建設等支出或財政刺激方案達成。
 匯率政策(升值以減緩出口)：
 人民幣、日幣的角色很重要
 人民幣不升，其他韓幣台幣等，不容易升；
 政策協調問題，日幣不願參與協調
 因貿易間的連結日幣不一起協調，其他貨幣也難以調動。

4.4. Exchange rate

Definition 4-9 nominal exchange rate

要把自己當成美國人去想

美國人定義自己的 nominal exchange rate: the amount of foreign currency that

can be bought by 1 USD.

number of CAD
e=
$ 1 USD

照理說台灣定義自己的 nominal exchange rate 應該

number of USD
e=
$ 1 NTD

但台灣的定義

number of NTD
e=
$ 1 USD

*the level of e is determined in the foreign exchange market 18;

$ stronger$ appreciatee↑19

18
這個市場，不是有一大堆人擠在同一個地點交易實體的市場。而是一個抽象的概念

頁 33
Definition 4-10 real exchange rate

number of NTD
PTW
ϵ=
1 USD
PUS

分子部分：the number of TW goods that can be purchased by the amount of

NTD.

分母部分：the number of US goods that can be purchased with 1 USD.

方程式 4-5

number of NTD pUS p

ϵ= × TW =e × ¿
1 USD P p

p* is foreign price level

εbig foreign goods relatively cheapEX↓,IM↑NX↓

so, NX=NX(ε) 反比關係

4.5. How the real exchange rate is determined?

S−I
⏟ ( r ) = NX
⏟ ( ϵ)
supply demand
net capital outflow determine the
the supply of USD demand for USD

19
NTD stronger→NTD appreciate→e↓

頁 34
 S-I
ε

NX(ε)

NX,S-I

Policy analysis:

(1) tax cut:

S’-I
ε S-I

NX(ε)

NX,S-I

Tax cutS dropscapital outflows↓supply of USD in the foreign exchange

market↓;USD appreciate; e↑

p
Since p, p* unchanged(exogenous variable)ϵ =e ↑NX↓
p¿

A tax cut cause a decrease in net export!!

(2) 假設發生世界大戰，國外政府支出增加G foreign ↑

頁 35
 S-I S-I’
ε

NX(ε)

NX,S-I

G foreign ↑ ⇒r w ↑ ⇒ I ↓⇒ S−I ↑ ⇒ capital out flow ↑⇒ supply of USD ↑ ⇒ e ↓ ⇒ ϵ ↓ ⇒ NX ( ϵ ) ↑

4.6. The determinants of the nominal exchange rate

p p¿
ϵ =e ⇒ e=ϵ
p¿ p

取 log natural 再全微分

% Δe=% Δϵ+ %
⏟ Δ p¿ −%
⏟ Δp
π
¿
π

So, it is determined by:

1. the real exchange rate

2. the relative inflation rate

4.7. PPP: purchasing power parity

購買力平價學說

Assumption:

 Perfect capital mobility

 International trade

In equilibrium, the real exchange rate=1

PPP argue that the e would adjust to eliminate the arbitrage opportunity.

頁 36
 S-I
ε

NX,S-I

Evidence for PPP: not very strong

1. non-trade goods(land, service) will reflect in the price.

2. Transportation cost

5. I.O.U.S.A
David walker 美國審計長

2007 年負債 8.7 兆佔 GDP 13 兆的 64%

5.1. 主題是甚麼
美國債務國高，還債留子孫。呼籲國人注意國家債務問題。

5.2. 立論基礎

5.2.1. Budget deficit

2007 年美國 GDP 有 13 兆，負債 8.7 兆。居然在和平時期負債也佔 GDP 的 60 己趴

嬰兒潮的社會安全捐。嬰兒潮的人一退休，退休金和健保都不夠給付。

大政府的開銷；小政府的稅收

頁 37
5.2.2. Savings deficit
「不要買買不起的東西」的觀念，美國人民不擅儲蓄，月光族滿街跑，沒錢了就用信
用卡借錢來買，不論是民間，連政府的理財風氣皆是如此，因此「量入為出」的習慣
真的很重要。

5.2.3. Trade deficit

中國、日本、石油輸出國變成美國主要債權國

5.2.4. Leadership deficit

政府不減少開支，又要減稅。

5.3. 對台灣的啟示

6. Consumption
Theories from: Keynes, Fisher, M.Friedman

6.1. Keynesian consumption function

 Consumption depends on disposable income, but not so much on the interest
rate.
∂C
 (MPC) Marginal propensity to consume 邊際消費傾向b= , 0<b<1
∂ ( Y −T )
C
 (APC) Average propensity to consume APC= ，falls when income rise.
Y −T

-----------------------------------4/28

C 2=−( 1+r ) C1 + [ Y 2 + ( 1+r ) Y 1 ]

頁 38
 C2

ΔC2

ΔC1
C1

ΔC 2
: by having one more unit of C1, how much C2 should I give up?→+(1+r)
ΔC 1

Represent the price of C2 in terms of C1.20

Note that (1+r) is always greater than 1, since r is non-negative! Be cautious

when drawing the graph.

C2

C1

未完待補

7. Growth model

7.1. Steady state

7.2. Golden rule

7.3. Population growth

ΔL
population growth rate : =n>0
L

In general case:預算線的斜率意義就是「橫軸商品的價格以縱軸來表示」
20

頁 39
 K
what happens to k = if no investment?
L

1. Depreciation: K↓at the rate of δ

2. Population growth: L↑at the rate of n

Therefore, k↓ at the rate ofδ+n if no investment.21

So, the “break even investment22”

i=( δ +n ) k ,∨I = ( δ +n ) K

Therefore,

Δk =s ⋅ f ( k )−( δ +n ) k

式子的意義是：現在總投資 s*f(k)除了考慮彌補折舊掉的資本，還要分給成長的人口，
資本才會增加。

y (δ+n)k

sf(k)

k
k*

K
k ¿: k ¿= :constant y ¿ : y ¿ =( k ¿ ) : constantY ¿ :Y ¿ =L⋅ y ¿ :increaseat rate of n
L

The effect of n↑:k*, y* at lower level in steady state.

The Golden Rule: maximize C23

21
%Δk=%ΔK −%ΔL=−δ−( n )=− ( δ+n )
22
The i (or I) that keeps K/L constant

頁 40
C= y−i =f ( k ) −( n+δ ) k , at k ¿GR MPK =( n+δ )

8. The technology change

雖然生產技術的進步可以直接反映在生產函數上。但有個簡單的做法比較容易分析，
而且做出來的結果也很符合預期。

Y =F ( k , L× E ) E :labor efficiency

因為技術的進步，就好像勞工變多了一樣。Labor augmenting technology improves

the efficiency of labor.

L*E: the number of effective worker.

Increase in E is like increases in labor force.

So even if K, L are constant, E↑Y↑

Assume:

ΔE
=g
E

So, we have L growth at n, E growth at g, L*E growth at n+g

Now define:

K Y
k= :capital per efficient worker y=
¿ ¿

the breakeven level of i (the i keep k constant) is:

i=( n+ g+ δ ) k

23
At steady state, Δk =0=i−( n+ δ ) k , i=( n+ δ ) k

頁 41
 y (δ+n+g)k

sf(k)

k
k*

At steady-state:

Y Y
¿
k ¿ : constant y : y=f ( k ) constant
L ( )
=E ⋅ y , grows at gY =L
L
, growsat n+ g

Summary:

Growth of Y in Growth of Y/L in

Steady state Steady state
Y=F(K, L)
L fixed 0 0
L grows at n n 0
Y=F(K, LE)
L grows at n, E grows at n+g g
g
Steady state:

Δk=0

The Golden Rule: maximize C

∂C
=0
∂ k ss

Things that affect Long-Run level of Y

1. Technology: δ, n

頁 42
2. Biology: n 提供誘因使生小孩的機會成本增加(例如讓婦女受教育，有一分薪水不
錯的工作，養小孩的機會成本增加)
3. Preference: s

Facts:

1. [rate] sustained growth in Y/L

2. [rate] the growth rate of Y/L slow down
3. [level] Differences in Y/L across countries

For 1 and 2, concerns g.

Y
g>0 ⇒ sustained growth∈
L

but why the growth slow down? Can’t be explained by this model.

About3:Assume technology is the same across countries.( g,δ,E)

Question: will poor countries grow faster (in terms of Y/L) and catch up to the
rich ones?(邁向世界大同？)

Important: the growth rate during the transition period depends on how far it is
away from the s-s. the farther the faster.

Scenario1: s, n are also the same across countries. Countries differ only in the
initial capital stock.

y (δ+n+g)k

sf(k)

k
kTW kUS k*

頁 43
1. Assume all countries have the same steady state.
2. TW will grow faster. ”catch-up phenomenon”
3. Since converge to the steady state, it is called “absolute convergence”
4. In absolute convergence, poor countries grow faster.

Scenario 2: countries different in n and initial capital stock.

y (δ+n1+g)k

sf(k)

kA k1* k

y (δ+n2+g)k

sf(k)

kB k2* k

1. n1>n2
2. Persistent Long run differences in “level” of Y/L across countries.
3. Different steady state for different countries. conditional convergence
4. For kA<kB A is poor in this moment.
5. A does not necessarily grow faster than B.
6. In long run, k A <k B , y A < y B (level). But the growth rate y A = y B (rate)
¿ ¿ ¿ ¿ ¿ ¿

頁 44
補充：

K/L
Change in saving rate
s-s
slope=g

s-s
k
slope=g

time

上圖要說明我們討論的 growth rate 是在 steady state(s-s)的時候。中間 level 的改變

(如改變 saving rate)的 growth rate 不討論。

8.1. Growth accounting

Accounting for the sources of economic growth.

Y =F ( K , L )

 If K↑by 1 Y↑by MPK, If K↑by ΔK Y↑by MPK ⋅ ΔK so ΔY =MPK ⋅ ΔK

 Similarly, if L↑by 1 Y↑by MPL, If L↑by ΔL Y↑by MPL ⋅ ΔLso
ΔY =MPL ⋅ ΔL
 If both K and L change, then

ΔY =MPK ⋅ ΔK + MPL⋅ ΔL … ( ¿ )

Dividing both side of (*) by Y:

ΔY MPK MPL MPK ⋅ K ΔK MPL⋅ L ΔL

Y
=
Y
⋅ ΔK +
Y
=
Y (
K
+
Y L ) ( )
⇒ %ΔY = ( MPKY ⋅ K )%ΔK +( MPLY ⋅ L )%ΔL
 MPK is capital‘s rental “price.”

頁 45
 ( MPKY ⋅ K )cost share of capital
 If F(K,L) is Cobb-Douglas with CRTS; Y =K α L1 -α

 Then ( MPKY ⋅ K )=α

Technology:

注意之前用的是 labor augmenting technology “E*L”

這邊要用的是”total factor productivity” (easier for growth accounting)

Y = A ⋅ F (K , L)

ΔY ΔA
Similarly, = if A change
Y A

ΔY F ( ⋅ ) Δ A ΔA
 If A↑by 1 Y↑by F(‧),If A↑by Δ A Y↑by F ( ⋅ ) Δ A = =
Y A ⋅ F ( ⋅) A

%ΔY
⏟= %ΔA
⏟ +α %ΔK + ( 1−α ) %ΔL
growth growth∈¿ total factor
¿output productivity

ΔA
How to measure from the data?
A

%ΔA =%ΔY −α %ΔK −( 1−α ) %ΔL

Is called “Solow residual.” 是用複迴歸模型去算產出勞力和資本的關係，剩下不能解

釋的部份歸因於科技進步。

頁 46
9. Aggregate demand I.
Labor market

Money market
Goods market

Aggregate demand

Long run 有 growth; short run 有 fluctuation。經濟學家關心如何用政策縮小

fluctuation

Keynesian cross(goods market) IS curve

IS

Represent the relationship between r & Y when the goods market is in

equilibrium.

IS 上每一點都是商品市場的均衡

頁 47
Theory of liquidity preference (money market)

LM

Represents the relationship between r & Y when the money market is in

equilibrium

Wage theory(labor market)  AS curve

P
AS

Represent the relationship between P and Y when the labor market is in

equilibrium.

IS+LM  AD curve

頁 48
 P

AD

Represent the relationship between P & Y when both the goods and money
markets are in equilibrium.

AD+AS

P AS

E
‧

AD

The point when the three markets are in equilibrium.

9.1. Keynesian Cross

Illustrate the equilibrium condition of the goods market.

Y ¿⏟ C + I +G∨. Y
⏟ = AE
⏟
equilibrium actual planned
condition output expenditure

AE
⏟ ≝C +I+G
aggregate
expenditure

頁 49
 AE
E=C+I+G;slope=MPC<1

45

∂ AE
AE=c ( Y −T́ ) + Í + Ǵ =c
∂Y

9.1.1. Government purchase multiplier

AE Y=E

AE’

AE

ΔG

ΔY Y

ΔY > ΔG

1
Y =C ( Y −T ) + I +G ΔY = ΔG+ ΔG × MPC + ΔG × MPC2 +…
¿ ΔG (⏟
1−MPC )
government
purchase
multiplier

9.1.2. Tax Multiplier

Y =C ( Y −T ) + Í + Ǵ

頁 50
 −C −MPC
ΔY =
1−C
ΔT = Δ T (
1−MPC
⏟ )
tax multiplier

9.2. Using Keynesian Cross to Derive the IS curve

AE AE=C+I(r0)+G

AE’=C+I(r1)+G

45

r1

r0

IS

找下圖的內生變數、上圖的外生變數→就是 r r 1 >r 0

Every point on the IS curve is a goods market equilibrium. IS curve shifters:

everything that could affect AE except for r

9.3. The money market & the LM curve

The theory of liquidity preference

M
M : nominal money P : price level :real money balance ( RMB )
P

頁 51
Supply:

M s Ḿ
( )
P
=
P

Demand:

M d
( )
P
=L¿

S
i

M/P

Money supply 下降時

S’ S
i

M/P

在貨幣供給瞬間下降時，貨幣需求大於貨幣供給，由於產出不會改變，於是利率非得
上升。

Deriving the LM curve

頁 52
 L(r, y1) S
r r LM

L(r, y0)

M/P y0 y1 y

Every point on the LM curve represents an equilibrium in the money market.

r LM

Equilibrium in both the goods and money market.

‧

IS

此處的 y 不再區分 Y 或 y，全部指的是總產出

G↑

頁 53
 AE 45 度線

AE’

↑ΔG
AE

IS’

IS

Policy analysis:G↑

LM
r

IS’

IS

頁 54
 1
1. G↑IS shift to the right by ΔG ( 1 - MPC )
2. High Y increases money demand r must increase to suppress money
demand and to restore equilibrium in the money market.
3. r↑ cause I↓y↓
4. net effect
1
甲、 y↑ but by less than ΔG ( 1 - MPC )
乙、 r↑

9.3.1. Interactions between money and fiscal policies

Central bank’s goal:

1. Maintaining a healthy money market.

甲、 Target:
i. Money supply
ii. Interest rate
2. Fine tuning economic growth
甲、 Target: output growth rate

Example:

政府想增加稅收

 Keep money supply constant

頁 55
 LM
r
T↑ 使 IS 左移
。A
。D

IS

In Money Market:

S
r

。A

。D

M/P

 Keep interest constant

頁 56
 LM’ LM
r
T↑ 使 IS 左移

r0 。E 。A
。D

IS

LM must shift upward in order to keep r =r 0contractionary monetary policy

 Keep y constant

LM
r
T↑ 使 IS 左移 LM’

。A
。D

。E IS

y0 y

LM must shift downward in order to keep y= y 0expansionary monetary policy

9.3.2. Use IS+LM to derive AD:

1. Combine IS & LM to derive equilibrium in the demand side of market.
2. Allow P to be endogenous Long run analysis

頁 57
 r
LM(P0)

IS

P1

P0

AD

Every point on the AD curve represents an equilibrium in the demand side(goods

and money market) of the market.

貨幣供給的改變是改變總合需求面！(因為貨幣供給是影響 money market，屬於總合

需求面)

Effect of monetary policy: M S ↑ want: AD shift to right

頁 58
 r LM

LM’
。A

。D

IS

AD’

AD

y
P unchaged.

Effect of fiscal policy: G↑ want: AD shift to right

頁 59
 r LM

。D
。A

IS’
IS

AD’

AD

Conclusion: expansionary policies (G↑、M↑、T↓) shift AD to the right.

10. Aggregate supply

Sticky wage model:

1. w= ẃ

2. labor demand depends on real wage rate ( wP )P ↑⇒ ẃP ↓⇒ labor demand ↑ ⇒ y ↑

3. Problem: it implies countercyclical24 real wage rate which is inconsistent with
the fact.

24
反景氣循環(的變數)
Cov ( x , y ) < 0⇒ countercyclicalCov ( x , y ) > 0⇒ procyclicalCov ( x , y ) =0 ⇒ acyclical

頁 60
 explaintion of
Short-run economic
flutuation

Model of AS and
AD

Aggregate demand Aggregate supply

IS-LM model

IS LM

the market of real

Keynesian cross
money balance

Investment
function

頁 61
11. Some news

11.1. 央行澄清：沒有暗示新台幣升值
 2010-03-16
 新聞速報
 【中廣新聞／張雅惠】

    央行總裁彭淮南明天要到立法院財委會業務報告。依規定，書面資料要在兩天前
先送到立法院，書面報告提到，今年一到二月，新台幣兌美元升值，有助於減緩
「輸入性通膨壓力」，媒體報導，彭淮南提到這些是暗示央行為了抑制通膨，而讓
台幣升值。

    央行上午澄清，報導與事實不符，央行並沒有暗示台幣未來走勢，希望媒體不要
自行判斷，反而誤導讀者。

    央行也提到，書面報告強調匯率由市場供需決定，有偶發性或不正常因素干擾，
導致匯率過度波動而無法反映基本經濟情勢時，央行將進場調節，維持匯率市場秩
序。

    今天台北匯市，新台幣兌美元匯率開在三十一點八七兌換一美元，小幅貶值五分，
隨後在平盤附近狹幅震盪，一度升值五分，來到三十一點七七。

11.2. 台灣生活物價指數今公布 分甲乙丙三類

【大紀元 2009 年 10 月 5 日報導】主計處今將公布 9 月最新物價變動，並首度公布生
活物價指數，經建會表示，將分成甲乙丙三類，以甲類生活物價指數為例，將反應食
物、居住、交通等與民眾生活相關物價變動。

吳內閣上任即提出「庶民經濟」，行政院副院長朱立倫日前特別「點菜」，希望經建
會一個月內訂出生活物價指數，主計處下午將公布 9 月物價變動概況，也將一併公布
生活物價指數。

經建會表示，生活物價指數分甲乙丙三類，甲類生活物價指數涵蓋食物類、居住類的
水電燃氣、交通類的油料費，合計占目前消費者物價指數（CPI）權數 33%。

頁 62
乙類生活物價指數，則是把甲類加上教養娛樂，占 CPI 權數合計超過 50%；丙類則直
接參考韓國生活物價指數編制方法，納入生活必需品、每季購買一次以上、價格變動
較頻繁的項目。

根據主計處調查，8 月 CPI 年增率「-0.81%」，跌幅較 7 月的「-2.32%」大幅縮小；

主計處表示，已無通貨緊縮壓力，未來物價將溫和上漲。

11.3. USA health care25

為何歐巴馬急著改革？

Background

1. Discrimination over people that have: pre-existing condition(已經有病的人會

被保險歧視，但其實這些人最需要保險)
2. Unfairly high payment to medicare provides

Method and effect:

 Spend $940 billion for additional 32 million people

 Revenue raising & cost saving:
 Physician’s payment rate ↓21%
 Medicare provider’s payment rate is controlled under inflation rate
(變相減少的意思)
 Increase medicare payroll tax $210 billion
 Tax on high cost employer–sponsored coverage

Estimate effect on total federal deficit: Reduce $140billion!

25
Reference: congressional budget office, USA. www.cbo.gov

頁 63