Download ※經濟學依研究方法： ※生產可能曲線（PPC or PPF） ※需求

100-01 學科期中考前攻略（一）
《經濟學》100/11/01
※經濟學依研究方法：
（1）實證經濟學（唯真經濟學）
：只是闡明事實的真象（What it is）或因果關係，
並不做任何主觀的價值判斷。
（2）規範經濟學（唯善經濟學）
：涉及主觀的價值判斷，它以事先的判斷準則，
衡量經濟活動的好壞（What is good or bad）
，太
多或太少，以及應該如何做（How to do , What
should be）的問題。
※生產可能曲線（PPC or PPF）
（1）即生產技術、資源一定下，生產兩種財貨 x 以及 y 最大可能組合的軌跡。
（2）其斜率之意義為，維持在同一條生產可能曲線上（表示技術以及資源不變
之下）為了多生產一單位的 x 財貨，所需放棄 y 財貨的數量，亦即生產 x
的機會成本。
（3）絕對利益（absolute advantage）：
 比起其他生產者，使用較少數量的投入來生產商品；亦即可生產較多的商品。
（4）比較利益（comparative advantage）：
 一生產者放棄較少的其他商品來生產 X 商品時，我們說生產商品 X 的機會成
本較低，亦即生產者有比較利益生產 X 商品。
※需求
（1）需求定義：
在其他條件不變之下，消費者在特定的期間下，面對產品的某一價格，願意而
且能夠購買的數量。
（2）需求量的變動 v.s. 需求的變動
1. Change in quantity demanded：指在同一條需求曲線上，需求量因為本身價格的
變動而有所變動的情形。
（movement）
2. Change in demand：指本身價格以外的因素變動而導致整條需求曲線的移動。
（shift）
（3）影響需求的因素：
1. 所得：所得增加  Q Xd  ，此商品為正常財（normal good）
。
d
所得增加  Q X  ，此商品為劣等財（inferior good）
。
2. 相關商品價格： Py   Q yd   Q xd  ：表示 X 與 Y 為替代品（substitutes）。
Py   Q yd   Q xd ：表示 X 與 Y 為互補品（complements）。
3. 預期未來價格：預期未來商品價格會上漲  Q Xd 
4. 預期未來所得：預期未來所得會增加  Q Xd 
4. 偏好：對某商品的偏好增加  Q Xd 
5. 消費者人數：消費者人數愈多  Q Xd 
1
100-01 學科期中考前攻略（一）
《經濟學》100/11/01
※供給
（1）供給定義：
在其他條件不變之下，生產者在特定的期間下，面對產品的某一價格，願意而
且能夠銷售的數量。
（2）供給量的變動 v.s. 供給的變動
1. Change in quantity supplied：指在同一條供給曲線上，供給量因為本身價格的
變動而有所變動的情形。
（movement）
2. Change in supply：指本身價格以外的因素變動而導致整條供給曲線的移動。
（shift）
（3）影響供給的因素：
1.
2.
3.
4.
5.
生產技術：技術愈進步，生產成本愈低  Q XS 
生產要素價格：生產要素價格愈高，生產成本愈高  Q XS 
預期價格：預期未來商品價格會上漲  Q XS 
供給者人數：供給者人數愈多  Q XS 
天災：颱風  Q XS 
※需求的價格彈性 ( Price elasticity of demand )
Q
需求量變動百分比
Q P
1
Q
（1） E d  


 
 點的位置
P
價格變動百分比
P Q 需求線斜率
P
E d  1 ，具有彈性 ( Elastic )
E d  1 ，單一彈性 ( Unit elastic )
E d  1 ，不具彈性 ( Inelastic )
（2）弧彈性 ( midpoint formula )：
Q2  Q1
Q  Q2 / 2
Ed   1
P2  P1
P1  P2 / 2
（3）需求價格彈性愈大，表示消費者對於需求量對價格愈敏感，消費者的選擇
愈大。
（4）需求價格彈性與總收入( TR )或總支出( TE )的關係：
 當價格 P 上升時，需求量 Q 減少，故總收入或總支出 TR  TE  P  Q 如何變
化，則會不確定，端視需求價格彈性的大小。
1. E d  1  P與TR呈反向關係 ， P  TR  薄利多銷
2. E d  1  P與TR呈正向關係 ， P  TR  穀貴傷民
P  TR  穀賤傷農
3. E d  1  P與TR無關 ，即總收入不受價格影響。
（5）影響需求價格彈性大小之因素：( 消費者可選擇愈多，彈性愈大 )
1.替代品的多寡：替代品愈多  需求價格彈性愈大
2
100-01 學科期中考前攻略（一）
《經濟學》100/11/01
2.消費支出占所得比例：占所得比例愈大  需求價格彈性愈大
3.時間長短：時間愈長  需求價格彈性愈大
※供給的價格彈性( Price elasticity of supply )
Q
供給量變動百分比
Q P
1
Q
（1） E s 


 
 點的位置
P P Q 供給線斜率
價格變動百分比
P
E s  1 ，具有彈性 ( Elastic )
E s  1 ，單一彈性 ( Unit elastic )
E s  1 ，不具彈性 ( Inelastic )
（2）弧彈性 ( midpoint formula )：
Q2  Q1
Q  Q2 / 2
Es  1
P2  P1
P1  P2 / 2
（3）影響供給價格彈性大小之因素：
1.生產要素是否具多種用途：用途愈多  供給價格彈性愈大
2.生產成本隨產量變動之敏感性：愈敏感  愈不容易改變供給量  供給價格彈
性愈小
3.時間長短：時間愈長  供給價格彈性愈大
※需求所得彈性( Income elasticity of demand )
Q2  Q1
Q
Q  Q2 / 2
需求量變動百分比
Q M
Q



 1
Em 
M M Q
M 2  M1
所得變動百分比
M
M1  M 2 / 2
 E m  0 ，為正常財 ( normal goods )
E m  0 ，為中性財 ( neutral goods )
E m  0 ，為劣等財 ( inferior goods )
 E m  1 ，為奢侈品 ( luxury goods )
0  E m  1 ，為必需品 ( necessities )
※價格上限 ( price ceiling )
1.
2.
3.
4.
5.
6.
定義：政府規定產品最高價格不得超過？元
作法：有效價格上限，要將價格訂在均衡價格之下
目的：保護消費者
例子：油價調漲時
結果：出現 shortage，也就是 excess demand，因此出現黑市交易。
當需求彈性與供給彈性愈大，excess demand 會愈大。
3
100-01 學科期中考前攻略（一）
《經濟學》100/11/01
※ 價格下限 ( price floor )
1.
2.
3.
4.
5.
作法：有效價格下限，要將價格訂在均衡價格之上
目的：保護生產者，勞工
例子：最低工資
結果：出現 surplus，也就是 excess supply，因此出現生產過剩，出現失業。
當需求彈性與供給彈性愈大，excess supply 會愈大。
※決定無謂損失的因素：供給以及需求彈性
Case1： E d 愈大  消費者負擔的稅愈少，生產者負擔的稅愈多
 無謂損失愈大
Case2： E s 愈大  消費者負擔的稅愈多，生產者負擔的稅愈少
 無謂損失愈大
※Laffer Curve（拉佛曲線）
※出口國或是進口國？
（1） 若國內均衡價格（自給自足 autarky 下）高於國際價格，貿易結果將成為
進口國，且價格下降到 Pw ，消費者剩餘增加，生產者剩餘減少，社會福
利增加。
（2） 若國內均衡價格（自給自足 autarky 下）低於國際價格，貿易結果將成為
出口國，且價格上升到 Pw ，消費者剩餘減少，生產者剩餘增加，社會福
利增加。
※ 貿易政策
（1） 進口關稅：
消費者剩餘：減少
生產者剩餘：增加
關稅收入：增加
社會福利：減少
（2） 進口限額（quota）
消費者剩餘：減少 a,b,c,d
生產者剩餘：增加 a
進口商收入：增加 c
社會福利：減少 b,d
4
100-01 學科期中考前攻略（一）
《經濟學》100/11/01 ※PPF
1. The following table contains some production possibilities for an economy for a
given month.
Sweaters Gloves
4
300
6
?
8
100
If the production possibilities frontier is bowed outward, then “?” could be
a. 100.
b. 150.
c. 200.
d. 250.
ANS: D
2. Production possibilities frontiers are usually bowed outward. This is because
a. the more resources a society uses to produce one good, the fewer resources
it has available to produce another good.
b. it reflects the fact that the opportunity cost of producing a good decreases as
more and more of that good is produced.
c. of the effects of technological change.
d. resources are specialized, that is, some are better at producing particular
goods rather than other goods.
ANS: D
3.The difference between production possibilities frontiers that are bowed out and
those that are straight lines is that
a. bowed-out production possibilities frontiers apply to economies that face
tradeoffs, whereas straight-line production possibilities frontiers apply to economies
that do not face tradeoffs.
b. bowed-out production possibilities frontiers apply to economies in which
resources are not specialized, whereas straight-line production possibilities frontiers
apply to economies in which resources are specialized.
c. bowed-out production possibilities frontiers illustrate increasing opportunity
cost, whereas straight-line production possibilities frontiers illustrate constant
opportunity cost.
d. straight-line production possibilities frontiers illustrate real-world conditions,
whereas bowed-out production possibilities frontiers illustrate more simplistic
assumptions.
ANS: C
※Demand and Supply
1. What would happen to the equilibrium price and quantity of coffee if the wages of
coffee-bean pickers fell and the price of tea fell?
1 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 a. Price would fall and the effect on quantity would be ambiguous.
b. Price would rise and the effect on quantity would be ambiguous.
c. Quantity would fall and the effect on price would be ambiguous.
d. Quantity would rise and the effect on price would be ambiguous.
ANS:
A
2. Which of the following would shift the demand curve for gasoline to the right?
a. a decrease in the price of gasoline
b. an increase in consumer income, assuming gasoline is a normal good
c. an increase in the price of cars, a complement for gasoline
d. a decrease in the expected future price of gasoline
ANS:
B
3. What will happen to the equilibrium price and quantity of new cars if the price of
gasoline rises, the price of steel rises, public transportation becomes cheaper and more
comfortable, and auto-workers negotiate higher wages?
a. Price will fall and the effect on quantity is ambiguous.
b. Price will rise and the effect on quantity is ambiguous.
c. Quantity will fall and the effect on price is ambiguous.
d. Quantity will rise and the effect on price is ambiguous.
ANS:
C
4. When we move along a given demand curve,
a. only price is held constant.
b. income and the price of the good are held constant.
c. all nonprice determinants of demand are held constant.
d. all determinants of quantity demanded are held constant.
ANS:
C
5. Which of the following events could shift both the demand curve and the supply
curve for a good?
a. A technological advance pertaining to the production of the good is observed.
b. Incomes of all buyers of the good increase.
c. The number of sellers of the good increases.
d. Everyone revises upward their expectation of next month’s price of the good.
ANS:
D
6. What will happen to the equilibrium price and quantity of traditional camera film if
traditional cameras become more expensive, digital cameras become cheaper, the cost
of the resources needed to manufacture traditional film falls and more firms decide to
manufacture traditional film?
a. Price will fall and the effect on quantity is ambiguous.
b. Price will rise and the effect on quantity is ambiguous.
c. Quantity will fall and the effect on price is ambiguous.
d. The effect on both price and quantity is ambiguous.
ANS:
A
2 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 ※Elasticity
1. A good will have a more inelastic demand,
a. the greater the availability of close substitutes.
b. the broader the definition of the market.
c. the longer the period of time.
d. the more it is regarded as a luxury.
ANS:
B
2. When we move upward and to the left along a linear, downward-sloping demand
curve, price elasticity of demand
a. first becomes smaller, then larger.
b. always becomes larger.
c. always becomes smaller.
d. first becomes larger, then smaller.
ANS:
B
3. The discovery of a new hybrid wheat would increase the supply of wheat. As a
result, wheat farmers would realize an increase in total revenue if
a. the supply of wheat is elastic.
b. the supply of wheat is inelastic.
c. the demand for wheat is inelastic.
d. the demand for wheat is elastic.
ANS:
D
4. The demand for Chocolate Chip Cookie Dough ice cream is likely quite elastic
because
a. ice cream must be eaten quickly.
b. this particular flavor of ice cream is viewed as a necessity by many ice-cream
lovers.
c. the market is broadly defined.
d. other flavors of ice cream are good substitutes for this particular flavor.
ANS:
D
5. If the price elasticity of demand for tuna is -0.7, then a 1.5% increase in the price of
tuna will decrease the quantity demanded of tuna by
a. 1.05% and tuna sellers' total revenue will increase as a result.
b. 1.05% and tuna sellers' total revenue will decrease as a result.
c. 2.14% and tuna sellers' total revenue will increase as a result.
d. 2.14% and tuna sellers' total revenue will decrease as a result.
ANS:
A
6.A decrease in supply will cause the largest increase in price when
a. both supply and demand are inelastic.
b. both supply and demand are elastic.
c. demand is elastic and supply is inelastic.
d. demand is inelastic and supply is elastic.
3 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 ANS:
A
※Price floor and Price ceiling
1. If the government removes a binding price ceiling from a market, then the price
paid by buyers will
a. increase and the quantity sold in the market will increase.
b. increase and the quantity sold in the market will decrease.
c. decrease and the quantity sold in the market will increase.
d. decrease and the quantity sold in the market will decrease.
ANS:
A
2. A binding price floor will reduce a firm's total revenue
a. always.
b. when demand is elastic.
c. when demand is inelastic.
d. never.
ANS:
B
※Welfare
1. When a tax is levied on sellers of tea,
a. the well-being of both sellers and buyers of tea is unaffected.
b. sellers of tea are made worse off and the well-being of buyers is unaffected.
c. sellers of tea are made worse off and buyers of tea are made better off.
d. sellers and buyers of tea both are made worse off.
ANS:
D
2. Suppose your own demand curve for tomatoes slopes downward. Suppose also that,
for the last tomato you bought this week, you paid a price exactly equal to your
willingness to pay. Then
a. you should buy more tomatoes before the end of the week.
b. you already have bought too many tomatoes this week.
c. your consumer surplus on the last tomato you bought is zero.
d. your consumer surplus on all of the tomatoes you have bought this week is
zero.
ANS:
C
3. Which of the following will cause an increase in consumer surplus?
a. an increase in the production cost of the good
b. a technological improvement in the production of the good
c. a decrease in the number of sellers of the good
d. the imposition of a binding price floor in the market
ANS:
B
4. Which of the following will cause an increase in producer surplus?
a. the imposition of a binding price ceiling in the market
b. buyers expect the price of the good to be lower next month
c. the price of a substitute increases
4 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 d. income increases and buyers consider the good to be inferior
ANS:
C
5. Total surplus in a market will increase when the government
a. imposes a tax on that market.
b. imposes a binding price floor on that market.
c. removes a binding price ceiling from that market.
d. None of the above is correct.
ANS:
C
6. Coffee and tea are substitutes. Bad weather that sharply reduces the coffee bean
harvest would
a. increase consumer surplus in the market for coffee and decrease producer
surplus in the market for tea.
b. increase consumer surplus in the market for coffee and increase producer
surplus in the market for tea.
c. decrease consumer surplus in the market for coffee and increase producer
surplus in the market for tea.
d. decrease consumer surplus in the market for coffee and decrease producer
surplus in the market for tea.
ANS:
C
7. Suppose televisions are a normal good and buyers of televisions experience a
decrease in income. As a result, consumer surplus in the television market
a. decreases.
b. is unchanged.
c. increases.
d. may increase, decrease, or remain unchanged.
ANS:
D
8. A drought in California destroys many red grapes. As a result of the drought, the
consumer surplus in the market for red grapes
a. increases, and the consumer surplus in the market for red wine increases.
b. increases, and the consumer surplus in the market for red wine decreases.
c. decreases, and the consumer surplus in the market for red wine increases.
d. decreases, and the consumer surplus in the market for red wine decreases.
ANS:
D
※Tax
1. The deadweight loss from a $1 tax will be smallest in a market with
a. inelastic supply and elastic demand.
b. inelastic supply and inelastic demand.
c. elastic supply and elastic demand.
d. elastic supply and inelastic demand.
ANS:
B
2. When a tax is placed on the sellers of lemonade,
5 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 a. the sellers bear the entire burden of the tax.
b. the buyers bear the entire burden of the tax.
c. the burden of the tax will be always be equally divided between the buyers
and the sellers.
d. the burden of the tax will be shared by the buyers and the sellers, but the
division of the burden is not always equal.
ANS:
D
3. If the government removes a tax on sellers of a good and imposes the same tax on
buyers of the good, then the price paid by buyers will
a. increase and the price received by sellers will increase.
b. increase and the price received by sellers will not change.
c. not change and the price received by sellers will increase.
d. not change and the price received by sellers will not change.
ANS:
D
4. The size of a tax and the deadweight loss that results from the tax are
a. positively related.
b. negatively related.
c. independent of each other.
d. equal to each other.
ANS:
A
5. Suppose a tax of $1 per unit is imposed on a good. The more elastic the demand
for the good, other things equal,
a. the larger is the decrease in quantity demanded as a result of the tax.
b. the smaller is the tax burden on buyers relative to the tax burden on sellers.
c. the larger is the deadweight loss of the tax.
d. All of the above are correct.
ANS:
D
6. Which of the following statements is correct regarding a tax on a good and the
resulting deadweight loss?
a. The greater are the price elasticities of supply and demand, the greater is the
deadweight loss.
b. The greater is the price elasticity of supply and the smaller is the price
elasticity of demand, the greater is the deadweight loss.
c. The smaller are the decreases in quantity demanded and quantity supplied,
the greater the deadweight loss.
d. The smaller is the wedge between the effective price to sellers and the
effective price to buyers, the greater is the deadweight loss.
ANS:
A
※Laffer Curve
1. When a country is on the downward-sloping side of the Laffer curves, a cut in the
tax rate will
6 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 a. decrease tax revenue and decrease the deadweight loss.
b. decrease tax revenue and increase the deadweight loss.
c. increase tax revenue and decrease the deadweight loss.
d. increase tax revenue and increase the deadweight loss.
ANS:
C
※Export and Import
1. When a country allows trade and becomes an importer of a good,
a. consumer surplus and producer surplus both increase.
b. consumer surplus and producer surplus both decrease.
c. consumer surplus increases and producer surplus decreases.
d. consumer surplus decreases and producer surplus increases.
ANS:
C
2. A tariff on a product makes
a. domestic sellers better off and domestic buyers worse off.
b. domestic sellers worse off and domestic buyers worse off.
c. domestic sellers better off and domestic buyers better off.
d. domestic sellers worse off and domestic buyers better off.
ANS:
A
3. If the United States imposes a tariff on automobiles, then
a. total surplus in the American automobile market decreases.
b. producer surplus in the American automobile market increases.
c. U.S. imports of foreign automobiles decrease.
d. All of the above are correct.
ANS:
D
4. When a country that imports a particular good imposes an import quota on that
good,
a. consumer surplus increases and total surplus increases in the market for that
good.
b. consumer surplus increases and total surplus decreases in the market for that
good.
c. consumer surplus decreases and total surplus increases in the market for that
good.
d. consumer surplus decreases and total surplus decreases in the market for that
good.
ANS:
D
5. A major difference between tariffs and import quotas is that
a. tariffs create deadweight losses, but import quotas do not.
b. tariffs help domestic consumers, and import quotas help domestic producers.
c. tariffs raise revenue for the government, but import quotas create surplus for
those who get the licenses to import.
d. All of the above are correct.
7 100-01 學科期中考前攻略（一）
《經濟學》100/11/01 ANS:
C
6. Import quotas and tariffs produce similar results. Which of the following is not one
of those results?
a. The domestic price of the good increases.
b. Consumer surplus of domestic consumers increases.
c. Producer surplus of domestic producers increases.
d. A deadweight loss is experienced by the domestic country.
ANS:
B
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