Download 一、選擇題︰一題1 分

台灣知識庫文教機構
2015 年暑期班第四次大考
命題教師：楊莉
考試時間：60 分鐘
範圍:消費者均衡解與修正凱因斯模型；
選擇題︰一題 1 分，計算題︰一題 2 分, 總分 115 分
一、選擇題︰一題 1 分
1.Bob views apples and oranges as perfect substitutes in his consumption, and MRS=1
for all combinations of the two goods in his indifference map Suppose the price of
apples is $2 per pound, the price of oranges is $3 per pound, and Bob’s budget is 430
per week. What is Bob’s utility maximizing choice between these two goods?
(A) 4 pounds of apples and 6 pounds of oranges.
(B) 5 pounds of apples and 5 pounds of oranges.
(C) 10 pounds of oranges and no apples.
(D) 15 pounds of apples and no oranges. 【100 政大商學院】
2.Assume that we have a demand curve of the form: log (Q)  a  b log (P)  c log (I) ,
where Q  quantity, P  price, I  income, and a, b, and c are positive constants.
The income and price elasticities for the demand curve represented above are always
(A)equal to one. (B) equal to zero. (C)equal (i.e., income elasticity always equals
price elasticity). (D) constant but not necessarily equal to one another. 【100 政
大商學院】
3.Consumers will be in equilibrium with respect to the consumption of two goods if :
(A)the ratio of marginal utility to price is equal for both goods.
(B) the marginal utility of the lowest price good is greater than the marginal utility of
the highest price good.
(C)the ratio of the marginal utility of A to the marginal utility of B is equal to the ratio
of the price of B to the price of A.
(D) the marginal utility of both goods is identical, regardless of the price.(E)none of
the above.【100 中正企研所】
4.Identify the reasons why the quantity demanded of a product increases as the price
of that product decreases.
(A) as the price declines, the real income of the consumer increases
(B) as the price of product A declines, it makes it more attractive than product B
(C) as the price declines, the consumer will always demand more on each successive
price reduction
(D) (A) and (B)
(E) (A) and (C)【100 中正企研所】
5.Mikey is very picky and insists that his mom make his breakfast with equal parts of
cereal and apple juice-any other combination will end up on the floor. Cereal costs 4
cents per tablespoon and apple juice costs 6 cents per tablespoon. If Mikey’s mom
budgets $8 per month for Mikey’s breakfast, how much cereal and juice does she
buy?
(A) 40 tablespoons each of cereal and juice.
(B) 80 tablespoons each of cereal and juice.
(C) 40 tablespoons of cereal and 75 tablespoons of juice.
(D) 100 tablespoons of cereal and 67 tablespoons of juice. 【99 政大商學院】
6.If there are only two goods, if more of good 1 is always preferred to less, and if less of
good 2 is always preferred to more, then indifference curves
(A)slope downward.
(B)slope upward.
(C)may cross.
(D)could take the form of ellipses.
(E)None of the above. 【100 中正國經所】
7.Ambrose has the utility function U ( x1, x2 )  4 x10.5  x2 . If Ambrose is initially consuming
25 units of nuts and 17 units of berries, then what is the largest number of berries
that he would be willing to give up in return for an additional 39 units of nuts?
(A)8
(B)12 (C)25 (D)6 (E)3【100 中正國經所】
8.Ollie has a utility function U ( x, y)  ( x  2)( y  3) . The price of x is $1 and the price of y
is $1. When he maximizes his utility subject to his budget constraint, he consumes
positive amounts of both goods. Ollie consumes
(A)exactly as many units of x as of y.
(B)1 more unit of x than he consumes of y.
(C)1 more unit of y than he consumes of x.
(D)2 more units of x than he consumes of y.
(E)None of the above. 【100 中正國經所】
9.Angela consumes only two goods, x and y. Her income doubles and the prices of the
two goods remain unchanged. Assuming that she is a utility maximizer and likes
both goods,
(A)she will consume more of both goods.
(B)the ratio of her consumption of x to y remains constant.
(C)her utility doubles.
(D)if her preferences are convex, she must consume more x.(E)None of the above.
【100 中正國經所】
10.Wilma Q has a utility function U ( x1, x2 )  x12  1.5x1x2  30x2 . The prices are P1  $1 and
P2  $1 P. For incomes between $20 and $60, the Engel curve for good 2 is
(A)upward sloping.
(B)downward sloping.(C)vertical.
(D)upward sloping for
incomes between $20 and $40 and downward sloping between $40 and $60.
(E)downward sloping for incomes between $20 and $40 and upward sloping between
$40 and $60. 【100 中正國經所】
11.Which of the following utility functions represent preferences of a consumer who
does not have homothetic preferences?
(A) U ( x, y)  xy .
(B) U ( x, y)  x  2 y .
(C) U ( x, y)  x  y 5 .
(D) U ( x, y)  min{x, y} .
(E)More than one of the above. 【100 中正國經所】
12.Charlie's utility function is X A X B . The price of apples used to be $1 per unit and the
price of bananas was $2 per unit. His income was $40 per day. If the price of apples
increased to $1.50 and the price of bananas fell to $1.75, then in order to be able to
just afford his old bundle, Charlie would have to have a daily income of (A)$23.75.
(B)$47.50.
(C)$96. (D)$71.25.
(E)$190.
【100 中正國經所】
13.Which of the following utility functions represent the same preferences as
U ( x, y )  x  y ? (A) U ( x, y)  10 xy . (B) U ( x, y)  x  y .(C) U ( x, y)  ln x  ln y x  y . (D)All of
these【100 逢甲財金所】
14.If an individual's utility function is given by U ( x, y)  xy and I  100 , px  1 ,
p y  4 , his or her preferred consumption bundle will be:
(A)(20, 20).
(B) (50, 12.5).
(C) (40, 15).
(D)(30, 15). 【100 逢甲財金所】
15.Consider the following three market baskets.
Basket Good x Good y
A
2
6
B
6
4
C
4
5
If Basket A and Basket B are on the same indifference curve, preferences satisfy the
usual assumptions, and the indifference curves have a diminishing marginal rate
of substitution, (A) Basket C is preferred to Basket A.(B) Basket A is preferred to
Basket C.(C) The consumer is indifferent between Basket A and Basket C.(D)
There is not enough information to determine how the consumer would rank
Basket A relative to Basket C. 【98 中山企研所】
16.As a consumer moves along an indifference curve and decreases consumption of the
good on the x-axis, the consumer needs ____ of the good on the y-axis to give up an
additional unit of the good on the x-axis.
(A)more and more(B)less and less (C)a constant amount (D)none 【97 嘉大管研所】
17.Among the following four utility functions, which of them can be used to derive a
straight line Engle curve and it passes through the origin. (1) u  log x  y . (2)
u  log x  log y . (3) u  min{x, y} . (4) u  x  y .
(A) (1).
(B)(1)(2)
(C)(1)(2)(3).
(D)(1)(3).
(E)(2)(3)(4)
【97 中正國經所】
18.如果投資支出對利率的反應愈敏感時，(A)財政政策相對有效(B)貨幣政策相對有(C)此時
經濟體系處於流動性陷阱，貨幣政策完全無效(D)此時經濟體系處於流動性陷阱，兩者皆
無效(E)以上皆非【100 北大經研所】
19.Consider an increase in government purchases in the IS-LM model.
(A) The IS curve shifts to the left.
(B) The increase in government purchases raises income, interest rates, and the price
level.
(C) Crowding out occurs because expansionary fiscal policy causes interest rates to
rise, thereby reducing government purchases.
(D) The increase in income in response to the fiscal expansion is larger than it is in the
Keynesian cross.
(E) Suppose the monetary authorities increase the money supply to keep the interest
rate at its original level, the increase in income in response to the fiscal expansion
will be the same as it is in the Keynesian cross. 【100 清大計量財金所】
20.某經濟體之 IS 曲線為 Y  50010000R ， LM 曲線為 Y  200 10000R 。其中 Y 為所得、 R 為
利率。則該總體經濟均衡 (Y * , R* ) 為(A)(200, 2%)(B)(100, 2%)
(C)(200, 1%)
(D)(300,
1%) (E)(350, 1.5%) (2%) 【97 交大科管所】
21.承上題，若在該經濟體中貨幣供給量突然緊縮，則根據凱因斯學派的分析，短期下該總
體經濟均衡的變化為：(A)利率上升且所得下降且失業量增加(B)利率上升且所得下降且
失業量增加(C)利率下降且所得增加且失業量減少(D)利率上升且所得增加且失業量減少
(E)利率上升且所得上升且失業量上升 (2%)
【97 交大科管所】
22.承上題，若在該經濟體中自發性投資突然增加，則根據凱因斯學派的分析，短期下該總
體經濟均衡的變化為：(A)利率上升且所得下降且失業量增加(B)利率上升且所得下降且
失業量增加(C)利率下降且所得增加且失業量減少(D)利率上升且所得增加且失業量減少
(E)利率上升且所得上升且失業量上升 (2%)
【97 交大科管所】
23.承上題，若在該經濟體中自發性投資突然減少且貨幣供給量突然增加，則根據凱因斯學
派的分析，短期下該總體經濟均衡的變化為：(A)利率上升
(D)所得增加 (E)失業量增加 (2%)
(B)利率下降
(C)所得下降
【97 交大科管所】
24. Which of the following cause a rightward shift in the money demand curve?
(A)a reduction in income(B)an increase in the money supply(C)a reduction in the
interest rate(D)none of the above
25.Which of the following statement is consistent with a given (i.e., fixed) IS curve?
(A)A reduction in the interest rate causes investment spending to increase.
(B)An increase in government spending causes an increase in demand for goods.
(C)An increase in taxes causes a reduction in demand for goods.
(D)A reduction in the interest rate causes an increase in the money supply.
26.Suppose investment spending is NOT very sensitive to the interest rate. Given this
information, we know that:(A)the LM curve should be relatively steep.(B)the LM
curve should be relatively flat.(C)the IS curve should be relatively steep.(D)the IS
curve should be relatively flat. (2%)
27.Suppose there is a central bank purchase of bonds and simultaneous tax cut. We
know with certainty that this combination of policies must cause:
(A)an increase in the interest rate. (B)a reduction in interest rate.
(C)an increases in output. (D)a reduction in output.
28.Which of the following will occur if there is a reduction in consumer confidence?
(A)The LM curve will shift up. (B)The IS curve will shift rightward.
(C)The IS curve will shift leftward.(D)The LM curve will shift down.
29.Suppose fiscal policy makers implement a policy to reduce the size of a budget
deficit. Based on the IS-LM model, we know with certainty that the following will
occur in the short run as a result of this fiscal policy action.(A)Investment spending
will increase.(B)Investment spending will decrease.(C)There will be no change in
investment spending.(D)Investment spending may increase, decrease, or not
change.
30. “Crowing-out” occurs in the IS-LM model as rising government spending requires a
in the interest rate in order to
the demand for money at the new
equilibrium, thus
planned private investment.
(A)rise, keep constant, lowering (B)rise, raise, lowering
(C)fall, keep constant, raising
(D)fall, raise, lowering【100 銘傳經研所】
31.The crowding-out effect suggests that
(A)expansionary fiscal policy causes inflation.
(B)restrictive fiscal policy is an effective weapon against inflation.
(C)reduction in private spending resulting from the higher interest rates caused by a
budget deficit will largely offset the expansionary impact of a pure fiscal action.
(D)a budget surplus will cause the private demand for loanable funds, the interest
rate, and aggregate demand to fall. 【100 台大財金所】
32.In the Keynesian model, if an economy were caught in the liquidity trap.
Expansionary monetary policy would:
(A) Lower interest rates and stimulate investment spending,
(B) decrease the opportunity cost of holding money.
(C) Be unable to reduce the interest rate and therefore unable to stimulate investment
and aggregate demand.
(D) Lead to a direct increase in consumption, which would stimulate aggregate
demand.
【97 台大財金所】
33.造成 IS 向右移動之可能原因為： (A)自發性消費的減少 (B)自發性投資的增加 (C)外國
對本國產品偏好減少 (D)本國對外國產品的偏好增加 (E)以上皆非【中興企研所】
34.如果消費函數為 C=100+0.75YD, 則稅收增加 25 單位將會導致 IS 曲線向左移動： (A)25
單位 (B)50 單位 (C)75 單位 (D)100 單位
【中興企研所】
35.An increase in the marginal propensity to consume would cause the IS curve to (A)
make a parallel shift to the shift. (B) rotate to become flatter from its vertical
intercept. (C)rotate to become steeper from its vertical intercept. (D) make a
parallel shift to the left.
【成大財金所】
36.Suppose that investment is independent of GDP. Which part below would then
describe an IS-LM representation of a second economy in which investment is
positively correlated with GDP?
(A)No change in either the IS or the LM curves.
(B)A flatter IS curve and an unchanged LM curve.
(C)A steeper IS curve and an unchanged LM curve.
(D)A flatter LM curve and an unchanged IS curve.
(E)A steeper LM curve and an unchanged IS curve.
【政大經研
所】
37.Last year, Taiwan experienced its first economic recession since the central
government moved to Taiwan. Do you think which of the following causes is the
major initial cause for this negative growth in income? (A)The LM curve shifts to
the left. (B)The IS curve shifts to the left. (C)The aggregate supply curve shifts to
the left. (D)Both (A) and (B). (E)Both (B) and (C). 【中央企研所】
38.Which of the following statement is CORRECT? Under the liquidity trap,
(A)The LM curve is vertical line.
(B)The IS curve is vertical line.
(C)The monetary policy is the most effective policy in stimulating the economy.
(D) The fiscal policy is the most effective policy in stimulating the economy. 【101 政大
經研所】
39.The higher the interest sensitivity of investment, the(A)less effective is monetary
policy and the more effective is fiscal policy.(B)more effective are both monetary
and fiscal policies(C)less effective are both monetary and fiscal policies.(D)less
effective is fiscal policy and the more effective is monetary policy.(2 分)【102 中正企
研所】
影響產出，而財政政策越
40.邊際消費傾向越大，則貨幣政策越
(A)能，能
(B)能，不能
(C)不能，能
(D)不能，不能(2 分)【102 台大國企所】
影響產出，而財政政策越
41.投資對利率越敏感，則貨幣政策越
(A)能，能 (B)能，不能 (C)不能，能
影響產出：
影響產出：
(D)不能，不能(2 分)【102 台大國企所】
42.貨幣需求的所得彈性越大，則貨幣政策越
影響產出，而財政政策越
影響產
出：(A)能，能 (B)能，不能 (C)不能，能 (D)不能，不能(2 分)【102 台大國企所】
43.邊際進口傾向越大，則貨幣政策越
(A)能，能
(B)能，不能
影響產出，而財政政策越
(C)不能，能
影響產出：
(D)不能，不能(2 分)【102 台大國企所】
44.Fiscal policy involves manipulating(A)the supply of money.(B)consumption
spending.(C)federal subsidies and minimum wage values.(D)government spending
and taxes.(E)none of the above. (4 分)【102 暨南財金所】
45.如果一個經濟體系處於流動性陷阱，則：(A)利率變動對投資沒有影響(B)實質貨幣供給
的增加對利率沒有影響(C)公開市場操作將不會移動實質貨幣供給曲線(D)投資變動對總
和計畫性支出沒有影響(2 分)【102 淡江財金所】
二、計算題︰一題 2 分
◙Assume that a utility function is given by U  min{X,2Y} . Let PX , PY , be the prices
of X, Y and m be the income.
(1)Find the Marshallian demand for X.
(2)Find the Marshallian demand for Y.
(3)請計算間接效用函數。
◙某甲在消費蘋果( Q A )和香蕉( Q B )的效用函數下： U  min( aQ A , bQ B )
其中 a、b 為常數。又已知蘋果與香蕉的價格分為 PA ， PB ，請回答下列問題：
(4)求某甲對蘋果的普通需求函數。
(5)求某甲對香蕉的普通需求函數。
(6)求某甲的間接效用函數。
【台大財金所】
◙A consumer’s utility function is U  xy , where x and y denote the amounts of two
goods.
(7) Please specify the consumer’s Marshallian demand curve for good x if the
consumer’s income equals 200.
(8) Based on the demand curve from (7), find the price elasticity of demand for x
when its price equals 5. 【99 清大經研所】
◙(9)小明對橘子( X 1 )與蘋果( X 2 )的效用函數為 U ( X1 , X 2 )  4 X11/2  X 2 ，若他原來消費 25 顆
橘子與 18 顆蘋果，現在其要增加 11 顆橘子消費，在維持效用不變之下，則小明最多
要放棄多少顆蘋果？
◙某消費者消費 X 與 Y 兩種財貨，令 x 與 y 分別為其消費 X 與 Y 兩種財貨的數量，其效用
函數可表示為： U ( x, y)  min{3x  y , x  3 y} ，其中 U 為效用值，min 為極小值函數。
某消費者的所得為 60，又財貨 X 與 Y 的單位價格分別為 P 與 1。
(10)假設 P  2 ，則某消費者最適的財貨 X 消費量為
(11)假設 P  0.25 ，則某消費者最適的財貨 X 消費量為
單位。
單位。【96 台大財金所】
◙(12)【是非題】Every point on the demand curve is the optimal choice of the
consumer, which means, for a given price, the corresponding demand on that
curve guarantees the highest utility that the consumer can obtain.(True or False)
◙Ms. Caffeine enjoys coffee (C) and tea (T) according to the utility function
U (C, T )  3C  4T
(13)What does her utility function say about her marginal rate of substitution (MRS)
of coffee for tea?
(14)What do her indifference curve look like?
(15)If coffee and tea cost $3 each and Ms. Caffeine has $12 to spend on these products,
how much coffee and tea should she buy to maximize her utility?
(16)How would her consumption change if the price of coffee fell to $2?【政大風險管
理】
◙(17)【是非題】如果商品 X 相對商品 Y 的價格( PX / PY )為 3，而某消費者之 X 對 Y 的邊際
替代率( MRSXY )為 2 的情況下，這個人增加 X 的購買可以提高他的效用。
◙Sarah has $300 to allocate between opera tickets and movie tickets. The price of each
opera tickets is $60, and the price of each movie ticket is $6. Her marginal rate of
substitution (MRS) of opera tickets for movie tickets equal 5, regardless of what
market basket she choose.
(18)How many opera and movie tickets will she purchase?
(19)If the price of each opera ticket is $30 and the price of each movie ticket is $6, how
many opera and movie tickets will she purchase? 【96 高大經管所】
◙(20)某甲將其所得全數消費在 X 與 Y 二種商品，已知 X、Y 二商品之所得彈性分別為 0.92
與 1.24，則甲之所得中有多少百分比花在 X 商品上？
【台大財金所】
◙令 X1 表包子個數，X2 表香蕉個數，某人最喜歡的消費組合是(X1, X2)＝(3, 4)，吃的太多
或太少效用均不及消費(3, 4)時的水準，
(21)請畫出該消費者可能的無異曲線形狀？
(22)此無異曲線是否符合「負斜率」與「凸向原點」的特性？
(23)該消費者有這樣的消費偏好，他是否一定會將預算用完？【交大經管所】
◙(24)設某消費者的預算限制式為 PX0 X  PY0Y  M ，則當政府對 X 財貨之消費給予 50%的津
貼，並對 Y 財貨每單位之消費課徵 5 元的租稅，且同時對每位消費者收取人頭稅 100
元，求新預算限制式為何？
1
◙已知效用函數為： U  100X 4 Y 3
(25)求 X、Y 的邊際效用？( MU X  ? MU Y  ?)
(26)求 X、Y 的邊際效用是否會遞減？
(27)求 X、Y 的邊際替代率？( MRS XY  ?)【98 高應大人資所】
◙某甲的所得為 46，其消費 X 與 Y 兩種財貨，而其效用函數為 U(xy) = xy，其中 x 與 y
分別為某甲對財貨 X 與 Y 的消費量。財貨 Y 之單位價格為 4。財貨 X 之單位價格隨購買
量而有不同：購買前 3 單位之財貨 X 時之價格為 6；若購買數量超過 3 單位，則超過 3
單位的部份每單位價格為 4。
某甲對財貨 X 的最適消費量為 _(28)____。
當消費最適的財貨組合時，某甲的效用水準為 ___(29)___。【97 台大財金所】
◙(30)Walter consumes two goods, X and Y. Walter’s utility function can be
represented by U  10X 2 Y . The price of good X is $2, and the price of good Y is
$1. Walter has $30 to spend on the purchases of goods X and Y. If Walter is
maximizing his utility subject to his budget constraint, how many units of
goods X and Y should he buy?【99 中山企研所丁組】
◙(31)Ann’s utility function is U(x, y)  x  47 y  3y2 . Her income is $107. The price of x is
$1, and the price of y is $23. How many units of good x does Ann demand?【96 中
興財金所】
◙(32)假設環保人士非常在乎汽車排放量（或汽車節能減碳程度）的多寡，並以此作為汽車
需求與使用的條件。請畫出環保人士對於私人汽車需求的無異曲線，橫軸設定為碳排
放量，縱軸為汽車使用量。
(33)承上小題。若將橫軸改為節能減碳程度，其他不變，請重新回答上一題的問題。【99
中央經研所】
◙某人的效用函數為 U ( X ,Y )  X 1/4Y 3/4 ， X （橫軸）為食物數量， Y （縱軸）為其它財貨
數量。如果 X 及 Y 的價格 PX
 PY  10 元，所得 ( I ) 為
5000 元，試求：
(34)如果政府給予 3000 元的消費券（可以使用於 X 或 Y ）
，效用最大下的 X 及 Y 消費
組合。
(35)如果政府給予 3000 元的食物券（只能使用於 X ）
，效用最大下的 X 及 Y 消費組
合。
三、以下部分不用作答
效用函數
u  X Y 
X 財普通需求函數
M
XM 
(   ) Px
X Y
u  min  ; 
  
XM 
u( X , Y )  X  Y
XM 
U  X  b nY
U
X


U ( X ,Y )  
XM 
Y
M
U  b1  log( X1  a1 )  b2  log( X 2  a2 ) X 1
M
 Px   Py
PY  M
PX2  PX PY
YM 
PX 
XM 
1
PX1
YM 

PY1
M
YM 
X 2M
bPX
PY
M

1
P  1 P  1
X
1
1
2
PX PY 2
 PX
b I  b2 a1 P1  b1a2 P2
 1
(b1  b2 ) P1
PX  M
PX PY  PY2
YM 
M
XM 
M
 Px   Py
YM 
M  bPX M

b
PX
PX

1 1

X Y
Y 財普通需求函數
M
YM 
(   ) Py
Y
 PY
M
1
1
2
PX PY 2
 PY
b I  b2 P1a1  b1a2 P2
 2
(b1  b2 ) P2
★The utility function for two commodities X 1 and X 2 is
U( X1 , X 2 )   ln( X1  1 )   ln( X 2   2 )
For the above utility function, if     0.5 , 1  10 ,  2  20 , derive the demand
function terms of m, P1 , P2 (where m is income, P1 and P2 are prices for X 1
and X 2 .
(1)Derive the demand for X 1 and the demand for X 2 .
(2)Explain whether X 1 is normal good or inferior good.
(3)Explain whether X 1 and X 2 are substitute goods or complementary goods.【中山經研
所】
★The basic problem facing a typical consumer is to maximize her utility, subject to
limited resources. Answer the following questions. Given the utility function
U ( x1 , x2 )  ( x1  3) ( x2  2) and the constraint p1 x1  p2 x2  M :
(4)Find the optimal levels of x1* in terms of p1 , p 2 , and M.
(5)Find the optimal levels of x2* , in terms of p1 , p 2 , and M.
(6) Find all the comparative-static derivatives︰
x1
p1
, evaluate their signs,and interpret
their economic meanings.
(7) Find all the comparative-static derivatives︰
x1
p 2
, evaluate their signs,and interpret
their economic meanings.
(8) Find all the comparative-static derivatives︰
x1
M
, evaluate their signs,and
interpret their economic meanings.【96 中央經研所】
★Preference and Demand
(9)When we know the representative consumer with fixed proportion of expenditure
on good X and good Y, please derive the possible utility form to describe the
preference of the representative consumer.
(10)When we know the representative consumer with fixed quantities of consumption
on good X and good Y, please derive the possible utility form to describe the
preference of the representative consumer.【99 逢甲財稅；國貿所】
★(1) Max U   ln( X1  1 )   ln( X 2   2 )
 Max U   ln( X1  1 )   ln( X 2   2 )
m  P1 X 1  P2 X 2
s.t
L  0.5 ln( X1  10)  0.5 ln( X 2  20)  [ m  P1 X1  P2 X 2 ]
L
0
X 1

0.5
 P1  0
X 1  10
L
0
X 2

0.5
 P2  0
X 2  20
L
 0  m  P1 X 1  P2 X 2  0

X  20 P1
P 

 2
 X 2   1  ( X 1  10 )  20
X 1  10 P2
 P2 
∴ X 1M 
(2)
(3)
X 1
m
m  10 P1  20 P2
2 P1

1
0
2 P1
X 2M 
代入 m  P1 X1  P1 X1  10P1  20P2
20 P2  10 P1  2 m
2 P2
 X 1 為正常財
X 1M  20

 0  X 1 與 X 2 為互補品關係。
P2
2 P1
★(4-5) Max U  ( x1  3) ( x2  2)
s.t. p1 x1  p 2 x 2  M
L  ( x1  3) ( x2  2)   (M  p1 x1  p2 x2 )
L
F.O.C：
 0 , ( x2  2)   p1  0
x1
L
 0 , 1 ( x1  3)   p2  0
x 2
x 2  2 p1

 p1 x1  3 p1  p 2 x 2  2 p 2 帶回預算限制式
x1  3 p 2
p

p
p1 x1  p 2  1 x1  3 1  2   M
p2
 p2

2 p1x1  M  3 p1  2 p2
2 p1 x1  3 p1  2 p 2  M
x1 
M 3 p2
 
2 p1 2 p1
p

p
p1  2 x 2  2 2  3   p 2 x 2  M
p1
 p1

2 p2 x2  M  2 p2  3 p1
(6) x1 
x1
p1
(7)
x1
p2
x1
x2 
..........
3p
M
1  1
2 p2
2 p2
M 3 p2
 
2 p1 2 p1


2 p 2 x 2  2 p 2  3 p1  M
M p2

 0  表示 X 1 符合需求法則，普通需求曲線為負斜率。
p12 p12
1
 0  表示兩個財貨為毛替代品關係。
P1
1
 0  表示 X 1 為正常財。
M 2 P1
3p
M
★ x 2 
1 1
2 p2
2 p2
(8)
x 2


p 2
 M  3 p1 
3p
M
0
 12  
2
2

2 p2 2 p2
 2 p2 
 表示 X 2 符合需求法則，普通需求曲線為負斜率。

x 2
p1

3
 0  表示兩個財貨為毛替代品關係。
2 P2
★(9)財貨支出占所得比例固定不變，表示消費者偏好型態為「Cobb-Douglas utility
function」，
證明如下： U  X  Y 1 ，
效用極大化普通需求函數為 X M 
M
PX
；Y M 
(1   ) M
PY
PX  X

 X 財支出占所得比例: M  

Y 財支出占所得比例: PY  Y  ( 1  )

M
(10)消費者偏好型態為「完全互補」效用函數，假設  個 X 財必須搭配  個 Y 財才有一單
X Y
;  ，則效用極大化的普通需求函數為
  
位的效用，則效用函數表達為 U  min 
XM 
M
M
；Y M 
。
 PX   PY
 PX   PY
台灣知識庫
研究所暑期班
文教機構
總體經濟
範圍：貨幣數量說與流動性偏好理論
1.The interest-rate effect
a. depends on the idea that increases in
interest rates increase the quantity
of money demanded.
b. depends on the idea that increases in
interest rates increase the quantity
of money supplied.
c. is the most important reason, in the
case of the United States, for the
downward slope of the aggregatedemand curve.
d. is the least important reason, in the
case of the United States, for the
downward slope of the aggregatedemand curve.
2.The wealth effect stems from the idea
that a higher price level
a. increases the real value of
households’ money holdings.
b. decreases the real value of
households’ money holdings.
c. increases the real value of the
domestic currency in foreignexchange markets.
d. decreases the real value of the
domestic currency in foreignexchange markets.
3.For the U.S. economy, which of the
following helps explain the slope of the
aggregate-demand curve?
a. An increase in the price level
decreases the interest rate.
b. An increase in the price level
increases the interest rate.
c. An increase in the money supply
decreases the interest rate.
d. An increase in the money supply
increases the interest rate.
4.According to John Maynard Keynes,
a. the demand for money in a country is
determined entirely by that nation’s
central bank.
b. the supply of money in a country is
determined by the overall wealth of
the citizens of that country.
c. the interest rate adjusts to balance
the supply of, and demand for,
money.
d. the interest rate adjusts to balance
the supply of, and demand for, goods
and services.
5.According to classical macroeconomic
theory,
a. the price level is sticky in the short
run and it plays only a minor role in
the short-run adjustment process.
b. for any given level of output, the
interest rate adjusts to balance the
supply of, and demand for, money.
c. output is determined by the supplies
of capital and labor and the available
production technology.
d. All of the above are correct.
6.According to classical macroeconomic
theory,
a. output is determined by the supplies
of capital and labor and the available
production technology.
b. for any given level of output, the
interest rate adjusts to balance the
supply of, and demand for, loanable
funds.
c. given output and the interest rate,
the price level adjusts to balance the
supply of, and demand for, money.
d. All of the above are correct.
7.According to the liquidity preference
theory, an increase in the overall price
level of 10 percent
a. increases the equilibrium interest
rate, which in turn decreases the
quantity of goods and services
demanded.
b. decreases the equilibrium interest
rate, which in turn increases the
quantity of goods and services
demanded.
c. increases the quantity of money
supplied by 10 percent, leaving the
interest rate and the quantity of
goods and services demanded
unchanged.
d. decreases the quantity of money
demanded by 10 percent, leaving the
interest rate and the quantity of
goods and services demanded
unchanged.
8.Using the liquidity-preference model,
when the Federal Reserve increases the
money supply,
a. the equilibrium interest rate
decreases.
b. the aggregate-demand curve shifts to
the left.
c. the quantity of goods and services
demanded is unchanged for a given
price level.
d. the long-run aggregate-supply curve
shifts to the right.
9.While a television news reporter might
state that “Today the Fed lowered the
federal funds rate from 5.5 percent to
5.25 percent,” a more precise account of
the Fed’s action would be as follows:
a. “Today the Fed told its bond traders
to conduct open-market operations in
such a way that the equilibrium
federal funds rate would decrease to
5.25 percent.”
b. “Today the Fed lowered the discount
rate by a quarter of a percentage
point, and this action will force the
federal funds rate to drop by the
same amount.”
c. “Today the Fed took steps to
decrease the money supply by an
amount that is sufficient to decrease
the federal funds rate to 5.25
percent.”
d. “Today the Fed took a step toward
contracting aggregate demand, and
this was done by lowering the federal
funds rate to 5.25 percent.”
10.Liquidity preference theory is most
relevant to the
a. short run and supposes that the price
level adjusts to bring money supply
and money demand into balance.
b. short run and supposes that the
interest rate adjusts to bring money
supply and money demand into
balance.
c. long run and supposes that the price
level adjusts to bring money supply
and money demand into balance.
d. long run and supposes that the
interest rate adjusts to bring money
supply and money demand into
balance.
11.People choose to hold a smaller
quantity of money if
a. the interest rate rises, which causes
the opportunity cost of holding
money to rise.
b. the interest rate falls, which causes
the opportunity cost of holding
money to rise.
c. the interest rate rises, which causes
the opportunity cost of holding
money to fall.
d. the interest rate falls, which causes
the opportunity cost of holding
money to fall.
12.If expected inflation is constant and
the nominal interest rate increases by 2
percentage points, then the real interest
rate
a. increases by 2 percentage points.
b. increases, but by less than 2
percentage points.
c. decreases, but by less than 2
percentage points.
d. decreases by 2 percentage points.
13.Which of the following Fed actions
would both increase the money supply?
a. buy bonds and raise the reserve
requirement
b. buy bonds and lower the reserve
requirement
c. sell bonds and raise the reserve
requirement
d. sell bonds and lower the reserve
requirement
14.People hold money primarily because
it
a. has a guaranteed nominal return.
b. serves as a store of value.
c. can directly be used to buy goods and
services.
d. functions as a unit of account.
15.According to liquidity preference
theory, the opportunity cost of holding
money is
a. the interest rate on bonds.
b. the inflation rate.
c. the cost of converting bonds to a
medium of exchange.
d. the difference between the inflation
rate and the interest rate on bonds.
16.When the interest rate decreases, the
opportunity cost of holding money
a. increases, so the quantity of money
demanded increases.
b. increases, so the quantity of money
demanded decreases.
c. decreases, so the quantity of money
demanded increases.
d. decreases, so the quantity of money
demanded decreases.
reduces the quantity of money
demanded. This is shown as a
movement along the money-demand
curve. An increase in the price level
shifts money demand to the right.
b. an increase in the interest rate
increases the quantity of money
demanded. This is shown as a
movement along the money-demand
curve. An increase in the price level
shifts money demand leftward.
c. an increase in the price level reduces
the quantity of money demanded.
This is shown as a movement along
the money-demand curve. An
increase in the interest rate shifts
money demand rightward.
d. an increase in the price level
increases the quantity of money
demanded. This is shown as a
movement along the money-demand
curve. An increase in the interest
rate shifts money demand leftward.
Figure 1
17.In which of the following cases would
the quantity of money demanded be
largest?
a. r = 0.03, P = 1.4
b. r = 0.03, P = 1.2
c. r = 0.04, P = 1.2
d. r = 0.06, P = 1.0
18.According to liquidity preference
theory, an increase in money demand for
some reason other than a change in the
price level causes
a. the interest rate to fall, so aggregate
demand shifts right.
b. the interest rate to fall, so aggregate
demand shifts left.
c. the interest rate to rise, so aggregate
demand shifts right.
d. the interest rate to rise, so aggregate
demand shifts left.
19.According to liquidity preference
theory,
a. an increase in the interest rate
20.Refer to Figure 1. If the current
interest rate is 2 percent,
a. there is an excess supply of money.
b. people will sell more bonds, which
drives interest rates up.
c. as the money market moves to
equilibrium, people will buy more
goods.
d. All of the above are correct.
21.Refer to Figure 1. There is an excess
demand for money at an interest rate of
a. 2 percent.
b. 3 percent.
c. 4 percent.
d. None of the above is correct.
22.Refer to Figure 1. At an interest rate
of 4 percent, there is an excess
a. demand for money equal to the
distance between points a and b.
b. demand for money equal to the
distance between points b and c.
c. supply of money equal to the
distance between points a and b.
d. supply of money equal to the
distance between points b and c.
23.Refer to Figure 1. Which of the
following is correct?
a. If the interest rate is 4 percent, there
is excess money demand, and the
interest rate will fall.
b. If the interest rate is 3 percent, there
is excess money supply, and the
interest rate will rise.
c. Starting with an interest rate of 4
percent, the demand for goods and
services will increase until the
money market reaches a new
equilibrium.
d. None of the above is correct.
Figure 2. On the left-hand graph,
MS represents the supply of money
and MD represents the demand for
money; on the right-hand graph, AD
represents aggregate demand. The
usual quantities are measured along
the axes of both graphs.
.
MS
P2
P1
AD
Y2
Y1
24.Refer to Figure 2. What is measured
along the horizontal axis of the left-hand
graph?
a. nominal output
b. real output
c. the opportunity cost of holding
money
d. the quantity of money
24.Refer to Figure 2. What does Y
represent on the horizontal axis of the
right-hand graph?
a. the quantity of money
b. the rate of inflation
c. real output
d. nominal output
25.Refer to Figure 2. Which of the
following quantities is held constant as
we move from one point to another on
either graph?
a. the nominal interest rate
b. the quantity of money demanded
c. investment
d. the expected rate of inflation
r2
r1
MD
2
MD
1
26.Refer to Figure 2. If the graphs
apply to an economy such as the U.S.
economy, then the slope of the AD curve
is primarily attributable to the
a. wealth effect.
b. interest-rate effect.
c. exchange-rate effect.
d. Fisher effect.
27.Refer to Figure 2. A decrease in Y
from Y1 to Y2 is explained as follows:
a. The Federal Reserve increases the
money supply, causing the money-
demand curve to shift from MD1 to
MD2; this shift of MD causes r to
increase from r1 to r2; and this
increase in r causes Y to decrease
from Y1 to Y2.
b. An increase in P from P1 to P2
causes the money-demand curve to
shift from MD1 to MD2; this shift of
MD causes r to increase from r1 to
r2; and this increase in r causes Y to
decrease from Y1 to Y2.
c. A decrease in P from P2 to P1 causes
the money-demand curve to shift
from MD1 to MD2; this shift of MD
causes r to increase from r1 to r2;
and this increase in r causes Y to
decrease from Y1 to Y2.
d. An increase in the price level causes
the money-demand curve to shift
from MD2 to MD1; this shift of MD
causes r to decrease from r2 to r1;
and this decrease in r causes Y to
decrease from Y1 to Y2.
28.Refer to Figure 2. As we move from
one point to another along the moneydemand curve MD1,
a. the price level is held fixed at P1.
b. the interest rate is held fixed at r1.
c. the money supply is changing so as
to keep the money market in
equilibrium.
d. the expected inflation rate is
changing so as to keep the real
interest rate constant.
29.Refer to Figure 2. If the moneysupply curve MS on the left-hand graph
were to shift to the right, this would
a. represent an action taken by the
Federal Reserve.
b. shift the AD curve to the left.
c. create, until the interest rate
adjusted, an excess demand for
money at the interest rate that
equilibrated the money market
before the shift.
d. All of the above are correct.
30.Refer to Figure 2. Assume the
money market is always in equilibrium.
Under the assumptions of the model,
a. the real interest rate is higher at Y2
than it is at Y1.
b. the quantity of money is the same at
Y1 as it is at Y2.
c. the price level is higher at r2 than it
is at r1.
d. All of the above are correct.
31.Refer to Figure 2. Assume the
money market is always in equilibrium.
Under the assumptions of the model,
a. the quantity of goods and services
demanded is higher at P2 than it is
at P1.
b. the quantity of money is higher at Y1
than it is at Y2.
c. an increase in r from r1 to r2 is
associated with a decrease in Y from
Y1 to Y2.
d. All of the above are correct.
32.Refer to Figure 2. Assume the
money market is always in equilibrium,
and suppose r1 = 0.08; r2 = 0.12; Y1 =
13,000; Y2 = 10,000; P1 = 1.0; and P2 =
1.2. Which of the following statements
is correct?
a. When r = r2, nominal output is
higher than it is when r = r1.
b. When r = r2, real output is higher
than it is when r = r1.
c. When r = r2, the expected rate of
inflation is higher than it is when r =
r1.
d. If the velocity of money is 4 when r =
r2, then the quantity of money is
$3,000.
33.Refer to Figure 2. Assume the
money market is always in equilibrium,
and suppose r1 = 0.08; r2 = 0.12; Y1 =
13,000; Y2 = 10,000; P1 = 1.0; and P2 =
1.2. Which of the following statements
is correct? When P = P2,
a. investment is lower than it is when P
= P1.
b. nominal output is higher than it is
when P = P1.
c. the expected rate of inflation is
higher than it is when P = P1.
d. the velocity of money is higher than
it is when P = P1.
Figure3.
34.Refer to Figure 3. What quantity is
represented by the vertical line on the
left-hand graph?
a. the supply of money
b. the demand for money
c. the rate of inflation
d. the quantity of bonds that was most
recently sold or purchased by the
Federal Reserve
35.Refer to Figure 3. Which of the
following sequences (numbered arrows)
shows the logic of the interest-rate
effect?
a. 1, 2, 3, 4
b. 1, 4, 3, 2
c. 3, 4, 2, 1
d. 3, 2, 1, 4
36.Refer to Figure 3. For an economy
such as the United States, what
component of the demand for goods and
services is most responsible for the
decrease in output from Y1 to Y2?
a. consumption
b. investment
c. net exports
d. government spending
37.According to liquidity preference
theory, if the quantity of money
demanded is greater than the quantity
supplied, then the interest rate will
a. increase and the quantity of money
demanded will decrease.
b. increase and the quantity of money
demanded will increase.
c. decrease and the quantity of money
demanded will decrease.
d. decrease and the quantity of money
demanded will increase.
38.According to liquidity preference
theory, if the quantity of money supplied
is greater than the quantity demanded,
then the interest rate will
a. increase and the quantity of money
demanded will decrease.
b. increase and the quantity of money
demanded will increase.
c. decrease and the quantity of money
demanded will decrease.
d. decrease and the quantity of money
demanded will increase.
39.According to liquidity preference
theory, if there were a shortage of
money, then
a. the interest rate would be above
equilibrium and the quantity of
money demanded would be too large
for equilibrium.
b. the interest rate would be above
equilibrium and the quantity of
money demanded would be too small
for equilibrium.
c. the interest rate would be below
equilibrium and the quantity of
money demanded would be too small
for equilibrium.
d. the interest rate would be below
equilibrium and the quantity of
money demanded would be too large
for equilibrium.
40.If, at some interest rate, the quantity
of money demanded is greater than the
quantity of money supplied, people will
desire to
a. sell interest-bearing assets, causing
the interest rate to decrease.
b. sell interest-bearing assets, causing
the interest rate to increase.
c. buy interest-bearing assets, causing
the interest rate to decrease.
d. buy interest-bearing assets, causing
the interest rate to increase.
41.Which of the following is correct?
a. A higher price level shifts money
demand rightward.
b. When
money
demand
shifts
rightward, the interest rate rises.
c. A higher interest rate reduces the
quantity of goods and services
demanded.
d. All of the above are correct.
42.If there is excess demand for money,
then people will
a. deposit more money into interestbearing accounts, and the interest
rate will fall.
b. deposit more money into interestbearing accounts, and the interest
rate will rise.
c. withdraw money from interestbearing accounts, and the interest
rate will fall.
d. withdraw money from interestbearing accounts, and the interest
rate will rise.
43.People might deposit more money into
interest-bearing accounts,
a. making the interest rate fall, if there
is a surplus in the money market.
b. making the interest rate rise, if there
is a surplus in the money market.
c. making the interest rate fall, if there
is a shortage in the money market.
d. making the interest rate rise, if there
is a shortage in the money market.
44.Which of the following statements is
correct for the long run?
a. Output is determined by the amount
of capital, labor, and technology; the
interest rate adjusts to balance the
supply and demand for money; the
price level adjusts to balance the
supply and demand for loanable
funds.
b. Output is determined by the amount
of capital, labor, and technology; the
interest rate adjusts to balance the
supply and demand for loanable
funds; the price level adjusts to
balance the supply and demand for
money.
c. Output is determined by the amount
of capital, labor, and technology; the
interest rate adjusts to balance the
supply and demand for loanable
funds; the price level is relatively
slow to adjust.
d. Output responds to the aggregate
demand for goods and services; the
interest rate adjusts to balance the
supply and demand for loanable
funds; the price level adjusts to
balance the supply and demand for
money.
45.Which of the following statements is
correct for the short run?
a. Output is determined by the amount
of capital, labor, and technology; the
interest rate adjusts to balance the
supply and demand for money; the
price level adjusts to balance the
supply and demand for loanable
funds.
b. Output is determined by the amount
of capital, labor, and technology; the
interest rate adjusts to balance the
supply and demand for loanable
funds; the price level adjusts to
balance the supply and demand for
money.
c. Output responds to the aggregate
demand for goods and services; the
interest rate adjusts to balance the
supply and demand for money; the
price level is relatively slow to
adjust.
d. Output responds to the aggregate
demand for goods and services; the
interest rate adjusts to balance the
supply and demand for loanable
funds; the price level adjusts to
balance the supply and demand for
money.
46.A decrease in the interest rate could
have been caused by the money-demand
curve shifting
a. leftward because the price level fell.
b. leftward because the price level rose
c. rightward because the price level fell.
d. rightward because the price level
rose.
47.The interest rate falls if
a. either money demand or money
supply shifts right.
b. money demand shifts right or money
supply shifts left.
c. either money demand or money
supply shifts left.
d. money demand shifts left or money
supply shifts right.
48.People will want to hold more money
if the price level
a. or if the interest rate increases.
b. or if the interest rate decreases.
c. increases or if the interest rate
decreases.
d. decreases or if the interest rate
increases.
49.People will want to hold less money if
the price level
a. increases or if the interest rate
increases.
b. decreases or if the interest rate
decreases.
c. increases or if the interest rate
decreases.
d. decreases or if the interest rate
increases.
50.If the interest rate increases
a. or if the price level increases, then
people will want to hold more money.
b. or if the price level increases, then
people will want to hold less money.
c. or if the price level decreases, then
people will want to hold more money.
d. or if the price level decreases, then
people will want to hold less money.
51.Which of the following events would
shift money demand to the right?
a. an increase in the interest rate or an
increase in the price level
b. an increase in the interest rate, but
not an increase in the price level
c. an increase in the price level, but not
an increase in the interest rate
d. neither an increase in the interest
rate nor an increase in the price level
52.Which of the following events would
shift money demand to the left?
a. an increase in the interest rate or an
increase in the price level
b. an increase in the interest rate, but
not an increase in the price level
c. an increase in the price level, but not
an increase in the interest rate
d. neither an increase in the interest
rate nor an increase in the price level
53.Assume the money market is initially
in equilibrium. If the price level
increases, then according to liquidity
preference theory there is an excess
a. supply of money until the interest
rate increases.
b. supply of money until the interest
rate decreases.
c. demand for money until the interest
rate increases.
d. demand for money until the interest
rate decreases.
54.According to liquidity preference
theory, if the price level decreases, then
a. the interest rate falls because money
demand shifts right.
b. the interest rate falls because money
demand shifts left.
c. the interest rate rises because money
supply shifts right.
d. the interest rate rises because money
supply shifts left.
55.According to liquidity preference
theory, a decrease in the price level
causes the interest rate to
a. increase, which increases the
quantity of goods and services
demanded.
b. increase, which decreases the
quantity of goods and services
demanded.
c. decrease, which increases the
quantity of goods and services
demanded.
d. decrease, which decreases the
quantity of goods and services
demanded.
56.The most important reason for the
slope of the aggregate-demand curve is
that as the price level
a. increases, interest rates increase,
and investment decreases.
b. increases, interest rates decrease,
and investment increases.
c. decreases, interest rates increase,
and investment increases.
d. decreases, interest rates decrease,
and investment decreases.
57.Which of the following properly
describes the interest-rate effect?
a. A higher price level leads to higher
money demand; higher money
demand leads to higher interest
rates; a higher interest rate
increases the quantity of goods and
services demanded.
b. A higher price level leads to higher
money demand; higher money
demand leads to lower interest rates;
a higher interest rate reduces the
quantity of goods and services
demanded.
c. A lower price level leads to lower
money demand; lower money
demand leads to lower interest rates;
a lower interest rate reduces the
quantity of goods and services
demanded.
d. A lower price level leads to lower
money demand; lower money
demand leads to lower interest rates;
a lower interest rate increases the
quantity of goods and services
demanded.
58.If the Fed conducts open-market
sales, which of the following quantities
increase(s)?
a. interest rates, prices, and investment
spending
b. interest rates and prices, but not
investment spending
c. interest rates and investment, but
not prices
d. interest rates, but not investment or
prices
59.If the Fed conducts open-market
purchases, then which of the following
quantities increase(s)?
a. interest rates, prices, and investment
spending
b. interest rates and prices, but not
investment spending
c. prices and investment spending, but
not interest rates
d. interest rates, but not prices or
investment spending
60.The economy is in long-run
equilibrium. Suppose that automatic
teller machines become cheaper and
more convenient to use, and as a result
the demand for money falls. Other
things equal, we would expect that, in
the short run,
a. the price level and real GDP would
rise, but in the long run they would
both be unaffected.
b. the price level and real GDP would
rise, but in the long run the price
level would rise and real GDP would
be unaffected.
c. the price level and real GDP would
fall, but in the long run they would
both be unaffected.
d. the price level and real GDP would
fall, but in the long run the price
level would fall and real GDP would
be unaffected.
61.If the interest rate is above the Fed's
target, the Fed should
a. buy bonds to increase the money
supply.
b. buy bonds to decrease the money
supply.
c. sell bonds to increase the money
supply.
d. sell bonds to decrease the money
supply.
62.If the stock market booms, then
a. household spending increases. To
offset the effects of this on the price
level and real GDP, the Fed would
increase the money supply.
b. household spending increases. To
offset the effects of this on the price
level and real GDP, the Fed would
decrease the money supply.
c. household spending decreases. To
offset the effects of this on the price
level and real GDP, the Fed would
increase the money supply.
d. household spending decreases. To
offset the effects of this on the price
level and real GDP, the Fed would
decrease the money supply.
1.C
6.D
11.A
16.C
21.A
26.B
31.C
36.B
41.D
46.A
51.C
56.A
61.A
2.B
7.A
12.A
17.A
22.C
27.B
32.D
37.A
42.D
47.D
52.D
57.D
62.B
3.B
4.C
5.C
8.A
9.A
10.B
13.B 14.C 15.A
18.D 19.A 20.B
23.C 24.DC 25.D
28.A 29.A 30.D
33.A 34.A 35.D
38.D 39.D 40.B
43.A 44.B 45.C
48.C 49.D 50.D
53.C 54.B 55.C
58.D 59.C 60.B
總體經濟選擇題
Mankiw 習題
範圍:國民所得計算
1. In a simple circular-flow diagram,
total income and total expenditure are
a. never equal because total income
always exceeds total
expenditure.
b. seldom equal because of the
ongoing changes in an economy’s
unemployment rate.
c. equal only when one dollar is
spent on goods for every dollar
that is spent on services.
d. always equal because every
transaction has a buyer and a
seller.
2. In a simple circular-flow diagram,
a. households spend all of their
income.
b. all goods and services are bought
by households.
c. expenditures flow through the
markets for goods and services,
while income flows through the
markets for the factors of
production.
d. All of the above are correct.
3. In the actual economy, goods and
services are purchased by
a. households, but not firms or the
government.
b. households and firms, but not
the government.
c. households and the government,
but not firms.
d. households, firms, and the
government.
4. To compute GDP, we
a. add up the wages paid to all
workers.
b. add up the costs of producing all
final goods and services.
c. add up the market values of all
final goods and services.
d. take the difference between the
market values of all final goods
and services and the costs of
producing those final goods and
services.
5. GDP adds together many different
kinds of products into a single measure
of the value of economic activity by using
prices determined by
a. banks.
b. economists.
c. the government.
d. markets.
6. In order to include many different
goods and services in an aggregate
measure, GDP is computed using,
primarily,
a. values of goods and services
based on surveys of consumers.
b. market prices.
c. consumer and producer
surpluses.
d. costs of producing goods and
services.
7.Gross domestic product adds together
many different kinds of goods and
services into a single measure of the
value of economic activity. To do this,
GDP makes use of
a. market prices.
b. prices that government
economists believe reflect the
true value of goods and services
to society.
c. the assumption that quantities
of goods and services produced
are unchanged from year to year.
d. the assumption that prices of
goods and services are
unchanged from year to year.
8. In computing GDP, market prices
are used to value final goods and
services because
a. market prices do not change
much over time, so it is easy to
make comparisons between
years.
b. market prices reflect the values
of goods and services.
c. if market prices are out of line
with how people value goods, the
government sets price ceilings
and price floors.
d. None of the above is correct;
market prices are not used in
computing GDP.
9. If the price of a DVD player is three
times the price of a CD player, then a
DVD player contributes
a. more than three times as much
to GDP as does a CD player.
b. less than three times as much to
GDP as does a CD player.
c. exactly three times as much to
GDP as does a CD player.
d. to GDP but a CD player does not
contribute to GDP.
10. Which of the following is correct?
a. The market value of rental
housing services is included in
GDP, but the market value of
owner-occupied housing services
is not.
b. The market value of owneroccupied housing services is
included in GDP, but the market
value of rental housing services
is not.
c. The market values of both
owner-occupied housing services
and rental housing services are
included in GDP.
d. Neither the market value of
owner-occupied housing services
nor the market value of rental
housing services is included in
GDP.
11. The value of the housing services
provided by the economy's owneroccupied houses is
a. included in GDP, and the
estimated rental values of the
houses are used to place a value
on these housing services.
b. included in GDP, and the actual
mortgage payments made on the
houses are used to estimate the
value of these rental services.
c. excluded from GDP since these
services are not sold in any
market.
d. excluded from GDP since the
value of these housing services
cannot be estimated with any
degree of precision.
12. Suppose an apartment complex
converts to a condominium, so that the
former renters are now owners of their
housing units. Suppose further that a
current estimate of the value of the
condominium owners' housing services is
the same as the rent they previously
paid. What happens to GDP as a result
of this conversion?
a. GDP necessarily increases.
b. GDP necessarily decreases.
c. GDP is unaffected because
neither the rent nor the estimate
of the value of housing services
is included in GDP.
d. GDP is unaffected because
previously the rent payments
were included in GDP and now
the rent payments are replaced
in GDP by the estimate of the
value of housing services.
13. James owns two houses. He rents
one house to the Johnson family for
$10,000 per year. He lives in the other
house. If he were to rent the house in
which he lives, he could earn $12,000 per
year in rent by doing so. How much do
the housing services provided by the two
houses contribute to GDP?
a. $0
b. $10,000
c. $12,000
d. $22,000
14. GDP excludes most items that are
produced and sold illegally and most
items that are produced and consumed
at home because
a.
the quality of these items is not
high enough to contribute value
to GDP.
b.
measuring them is so difficult.
c.
the government wants to
discourage the production and
consumption of these items.
d.
these items are not reported on
income tax forms.
15. Estimates of the values of which of
the following non-market goods or
services are included in GDP?
a. the value of unpaid housework
b. the value of vegetables and other
foods that people grow in their
gardens
c. the estimated rental value of
owner-occupied homes
d. All of the above are included in
GDP.
16. Over the last few decades,
Americans have chosen to cook less at
home and eat more at restaurants.
This change in behavior, by itself, has
a. reduced measured GDP.
b. not affected measured GDP.
c. increased measured GDP only to
the extent that the value of the
restaurant meals exceeded the
value of meals previously cooked
at home.
d. increased measured GDP by the
full value of the restaurant
meals.
17. Over time, people have come to rely
more on market-produced goods and less
on goods that they produce for
themselves. For example, busy people
with high incomes, rather than cleaning
their own houses, hire people to clean
their houses. By itself, this change has
a. caused measured GDP to fall.
b. not caused any change in
measured GDP.
c. caused measured GDP to rise.
d. probably changed measured
GDP, but in an uncertain
direction; the direction of the
change depends on the difference
in the quality of the cleaning
that has resulted.
18. Ralph pays someone to mow his
lawn, while Mike mows his own lawn.
Regarding these two practices, which of
the following statements is correct?
a. Only Ralph’s payments are
included in GDP.
b. Ralph’s payments as well as the
estimated value of Mike’s
mowing services are included in
GDP.
c. Neither Ralph’s payments nor
the estimated value of Mike's
mowing services is included in
GDP.
d. Ralph’s payments are definitely
included in GDP, while the
estimated value of Mike’s
mowing services is included in
GDP only if Mike voluntarily
provides his estimate of that
value to the government.
19. A professional gambler moves from
a state where gambling is illegal to a
state where gambling is legal. Most of
his income was, and continues to be,
from gambling. His move
a. necessarily raises GDP.
b. necessarily decreases GDP.
c. doesn't change GDP because
gambling is never included in
GDP.
d. doesn't change GDP because in
either case his income is
included.
20. Which of the following is included in
GDP?
a. medical marijuana purchased
from a government-run
pharmacy by a glaucoma patient
b. recreational marijuana
purchased from a drug dealer by
a college student
c. recreational marijuana produced
and consumed by a man in his
attic
d. All of the above are included in
GDP.
21. Marijuana is an illegal good and
broccoli is a legal good. Which of the
following statements is true?
a. Darin grows and sells marijuana
to Lisa. When Darin and Lisa
get married, GDP falls.
b. Darin grows and sells marijuana
to Lisa. When Darin and Lisa
get married, GDP rises.
c. Darin grows and sells broccoli to
Lisa. When Darin and Lisa get
married, GDP falls.
d. Darin grows and sells broccoli to
Lisa. When Darin and Lisa get
married, GDP rises.
22. Which of the following statements is
correct?
a. The value of intermediate goods
is always included in GDP.
b. The value of intermediate goods
is included in GDP only if those
goods were produced in the
previous year.
c. The value of intermediate goods
is included in GDP only if those
goods are added to firms’
inventories to be used or sold at
a later date.
d. The value of intermediate goods
is never included in GDP.
23. Gasoline is considered a final good if
it is sold by a
a. gasoline station to a bus
company that operates a bus
route between San Francisco and
Los Angeles.
b. pipeline operator to a gasoline
station in San Francisco.
c. gasoline station to a motorist in
Los Angeles.
d. All of the above are correct.
24. A steel company sells some steel to a
bicycle company for $150. The bicycle
company uses the steel to produce a
bicycle, which it sells for $250. Taken
together, these two transactions
contribute
a. $150 to GDP.
b. $250 to GDP.
c. between $250 and $400 to GDP,
depending on the profit earned
by the bicycle company when it
sold the bicycle.
d. $400 to GDP.
25. Al’s Aluminum Company sells $1
million worth of aluminum to Shiny Foil
Company, which uses the aluminum to
make aluminum foil. Shiny Foil
Company sells $4 million worth of
aluminum foil to households. The
transactions just described contribute
how much to GDP?
a. $1 million
b. $3 million
c. $4 million
d. $5 million
26. One bag of flour is sold for $1.00 to a
bakery, which uses the flour to bake
bread that is sold for $3.00 to consumers.
A second bag of flour is sold to a
consumer in a grocery store for $2.00.
Taking these three transactions into
account, what is the effect on GDP?
a. GDP increases by $2.00.
b. GDP increases by $3.00.
c. GDP increases by $5.00.
d. GDP increases by $6.00.
27. Suppose there are only two firms in
an economy: Cowhide, Inc. produces
leather and sells it to Couches, Inc.,
which produces and sells leather
furniture. With each $1,000 of leather
that it buys from Cowhide, Inc., Couches,
Inc. produces a couch and sells it for
$3,000. Neither firm had any inventory
at the beginning of 2006. During that
year, Cowhide produced enough leather
for 20 couches. Couches, Inc. bought
80% of that leather for $16,000 and
promised to buy the remaining 20% for
$4,000 in 2007. Couches, Inc. produced
16 couches during 2006 and sold each
one during that year for $3,000. What
was the economy's GDP for the 2006?
a. $48,000
b. $52,000
c. $64,000
d. $68,000
28. Suppose there are only two firms in
an economy: Rolling Rawhide produces
rawhide and sells it to Chewy Chomp,
Inc., which uses the rawhide to produce
and sell dog chews. With each $2 of
rawhide that it buys from Rolling
Rawhide, Chewy Chomp, Inc. produces a
dog chew and sells it for $5. Neither
firm had any inventory at the beginning
of 2007. During that year, Rolling
Rawhide produced enough rawhide for
1000 dog chews. Chewy Chomp, Inc.
bought 75% of that rawhide for $1500
and promised to buy the remaining 25%
for $500 in 2008. Chewy Chomp, Inc.
produced 750 dog chews during 2007 and
sold each one during that year for $5.
What was the economy's GDP for 2007?
a. $3750
b. $4250
c. $5250
d. $5750
29. In 2007, Corny Company grows and
sells $2 million worth of corn to Tasty
Cereal Company, which makes corn
flakes. Tasty Cereal Company produces
$6 million worth of corn flakes in 2007,
with sales to households during the year
of $4.5 million. The unsold $1.5 million
worth of corn flakes remains in Tasty
Cereal Company’s inventory at the end
of 2007. The transactions just described
contribute how much to GDP for 2007?
a. $4.5 million
b. $6 million
c. $6.5 million
d. $8 million
30. The total sales of all firms in the
economy for a year
a. equals GDP for the year.
b. is larger than GDP for the year.
c. is smaller than GDP for the
year.
d. Any of the above is possible.
31. Transactions involving items
produced in the past, such as the sale of
a 5-year-old automobile by a used car
dealership or the purchase of an antique
rocking chair by a person at a yard sale,
are
a. included in current GDP because
GDP measures the value of all
goods and services sold in the
current year.
b. included in current GDP but
valued at their original prices.
c. not included in current GDP
because GDP only measures the
value of goods and services
produced in the current year.
d. not included in current GDP
because these items have no
current value.
32. Until recently, George lived in a
home that was newly constructed in
2005. In 2005, he paid $200,000 for the
brand new house. He sold the house in
2006 for $225,000. Which of the
following statements is correct regarding
the sale of the house?
a. The 2006 sale increased 2006
GDP by $225,000 and had no
effect on 2005 GDP.
b. The 2006 sale increased 2006
GDP by $25,000 and had no
effect on 2005 GDP.
c. The 2006 sale increased 2006
GDP by $225,000; furthermore,
the 2006 sale caused 2005 GDP
to be revised upward by $25,000.
d. The 2006 sale affected neither
2005 GDP nor 2006 GDP.
33. Tyler and Camille both live in
Oklahoma. A new-car dealer in
Oklahoma bought a new car from the
manufacturer for $18,000 and sold it to
Tyler for $22,000. Later that year,
Tyler sold the car to Camille for $17,000.
By how much did these transactions
contribute to U.S. GDP for the year?
a. $18,000
b. $22,000
c. $39,000
d. $57,000
34.Consider two cars manufactured by
Chevrolet in 2007. During 2007,
Chevrolet sells one of the two cars to
Sean for $24,000. Later in the same
year, Sean sells the car to Kati for
$19,000. The second automobile, with a
market value of $30,000, is unsold at the
end of 2007 and it remains in Chevrolet’s
inventory. The transactions just
described contribute how much to GDP
for 2007?
a. $24,000
b. $43,000
c. $54,000
d. $73,000
35. Which of the following is included in
U.S. GDP?
a. the value of production by an
American working in Morocco
b. the value of production by a
Moroccan working in the U.S.
c. Both (a) and (b) are correct.
d. Neither (a) nor (b) is correct.
36. Anna, a U.S. citizen, works only in
Germany. The value she adds to
production in Germany is included
a. in both German GDP and U.S.
GDP.
b. in German GDP, but it is not
included in U.S. GDP.
c. in U.S. GDP, but it is not
included in German GDP.
d. in neither German GDP nor U.S.
GDP.
37. An American company operates a
fast food restaurant in Romania. Which
of the following statements is accurate?
a. The value of the goods and
services produced by the
restaurant is included in both
Romanian GDP and U.S. GDP.
b. One-half of the value of the
goods and services produced by
the restaurant is included in
Romanian GDP, and the other
one-half of the value is included
in U.S. GDP.
c. The value of the goods and
services produced by the
restaurant is included in
Romanian GDP, but not in U.S.
GDP.
d. The value of the goods and
services produced by the
restaurant is included in U.S.
GDP, but not in Romanian GDP.
38. Quality Motors is a Japanese-owned
company that produces automobiles; all
of its automobiles are produced in
American plants. In 2007, Quality
Motors produced $20 million worth of
automobiles, with $12 million in sales to
Americans, $6 million in sales to
Canadians, and $2 million worth of
automobiles added to Quality Motors’
inventory. The transactions just
described contribute how much to U.S.
GDP for 2007?
a. $12 million
b. $14 million
c. $20 million
d. $34 million
39. Which of the following items is
included in U.S. GDP?
a. goods produced by foreign
citizens working in the United
States
b. the difference in the price of the
sale of an existing home and its
original purchase price
c. known illegal activities
d. None of the above is included in
U.S. GDP.
40. Which of the following items is
included in U.S. GDP?
a. final goods and services that are
purchased by the U.S. federal
government
b. intermediate goods that are
produced in the U.S. but that are
unsold at the end of the GDP
accounting period
c. goods and services produced by
foreign citizens working in the
U.S.
d. All of the above are included in
U.S. GDP.
41. Which of the following values would
be included in U.S. GDP for 2006?
a. the rent that John, an American
citizen, would have paid on his
home in New York in 2006 had
he not owned that home
b. the rent that Sarah, an
American citizen, paid on her
apartment in San Francisco in
2006
c. the value of the legal services
provided by Carlos, an attorney
and a Mexican citizen, who lived
in Houston and practiced law
there in 2006
d. All of the above would be
included in U.S. GDP for 2006.
42. Which of the following examples of
production of goods and services would be
included in U.S. GDP?
a. Samantha, a Canadian citizen,
grows sweet corn in Minnesota and
sells it to a grocery store in Canada.
b. Ian, an American citizen, grows
peaches for his family in the back
yard of their Atlanta home.
c. Leo, an American citizen, grows
marijuana in his Seattle home and
sells it to his friends and neighbors.
d. None of the above examples of
production would be included in
U.S. GDP.
43. Which of the following transactions
adds to U.S. GDP for 2006?
a. In 2006, Ashley sells a car that she
bought in 2002 to William for
$5,000.
b. An American management
consultant works in Mexico during
the summer of 2006 and earns the
equivalent of $30,000 during that
time.
c. When John and Jennifer were both
single, they lived in separate
apartments and each paid $750 in
rent. John and Jennifer got
married in 2006 and they bought a
house that, according to reliable
estimates, could be rented for
$1,600 per month.
d. None of the above transactions adds
to U.S. GDP for 2006.
44. The government of Wrexington, a
country which has adopted American GDP
accounting conventions, reported that GDP
in quarter 3 was $12 billion at an annual
rate. This means that the market value of
all final goods and services produced within
Wrexington in quarter 3 was
a. $3 billion.
b. $4 billion.
c. $12 billion.
d. $48 billion.
45. In a certain small country, the unit of
currency is the huck. That country’s
government recently announced that "GDP
amounted to 400 million hucks in the
quarter that just ended." Assuming this
country has adopted American GDP
accounting conventions, this statement
means that GDP,
a. without seasonal adjustment,
amounted to 100 million hucks in
the quarter that just ended.
b. with seasonal adjustment,
amounted to 100 million hucks in
the quarter that just ended.
c. without seasonal adjustment,
amounted to 400 million hucks in
the quarter that just ended.
d. with seasonal adjustment,
amounted to 400 million hucks in
the quarter that just ended.
1.D
2.D
3.D
4.C
5.D
6.B
7.A
8.B
9.C 10.C
11.A 12.D 13.D 14.B 15.C
16.D 17.C 18.A 19.A 20.A
21.C 22.C 23.C 24.B 25.C
26.C 27.B 28.B 29.B 30.B
31.C 32.D 33.B 34.C 35.B
36.B 37.C 38.C 39.A 40.D
41.D 42.A 43.C 44.A 45.B
台灣知識庫文教機構
2015 年暑期班第四次大考
命題教師：楊莉
考試時間：60 分鐘
範圍:消費者均衡解與修正凱因斯模型；
選擇題︰一題 1 分，計算題︰一題 2 分, 總分 115 分
一、選擇題：每題 1 分
1.(D)；
MU X 1 MUY 1
 
  X  15
PX
2
PY
3
Y 0
2：(C)；價格需求彈性=-b；所得彈性=c；根據 Homogeneity condition 可知，需求+交叉
需求彈性+所得彈性=0；因此(-b)+c=0；b=c；需求彈性等於所得彈性。
3.(A)
4.(D)；利用替代效果與所得效果來分析需求曲線形狀。
5:(B)；由題意可知：消費者效用函數為完全互補:
U  min(C , A)
Max
4C  6 A  800
s.t.
CA





  C  A  80
4
C

6
A

800


6.(B)；Good 1 為 Goods；Good 2 為 Bads，表示無異曲線為正斜率。
7.(B)； X 0  25 ， Y0  17 ， u0  4(25)0.5  17  37
37  4(25  39)0.5  x2  x2  5 ， X 2  5  17  12
8.(B)；均衡條件
MU X PX
y 3


 1  x  2  y  3 代入預算式∴ x  y  1
MU Y
PY
x 1
9.(E)；(A)若效用函數為 quasi-linear preference，則所得增加兩倍，由於 X 財為中性財，
需求量不變，而 Y 財需求量增加。(B)此題效用函數未必為 Homothetic preference，
Y 
 比例不一定固定不變。(D)若消費者為準線性偏好，亦為凸性偏好，
X
當所得增加， 
則 X 需求量不變。
10.(B)；消費者均衡條件：
Mu X 1
Mu X 2

P1
2 x  1.5 x2
 1
1
P2
1.5 x1  30
∴ x1  3x2  60  x1  60  3x2 代入預算線
60  2 x1  M  x2 Engel Curve 方程式，
表示 x2 的 Engel’s Curve 為負斜率
11.(C)
40
40
 10
 20 ， X B0 
2(2)
2(1)
M   1.5(20)  1.75(10)  47.5
12.(B)；原均衡， X A0 
13.(D)
14.(B)
15.(A)；MRS 遞減隱含消費者為凸性偏好，具有「平均優於極端」的消費傾向；C 組合為
A、B 的加權平均  xC 

xA  xB 2  6
y  yB 6  4


 4; yC  A

 5  ，故知對消費者而言，C
2
2
2
2

組合比 A、B 更好。
16.(A)；定義良好之偏好型態滿足：邊際替代率( MRSxy )遞減，隱含無異曲線凸向原點，故當
放棄的 X 財減少時，所需增加的 Y 財需遞增。
17.(E)；(1)準線性效用偏好的商品，不具有所得效果，恩格爾曲線為垂直線。
(2) u  log x  log y .ICC 為過原點的直線，表示 X 愈 Y 財貨所得彈性等於一，恩格
爾曲線為過原點的直線。
(3) u  min{x, y} . ICC 為過原點的直線，表示 X 愈 Y 財貨所得彈性等於一，恩格爾
曲線為過原點的直線。
(4) u  x  y .效用最大均衡解為角隅解 ，ICC 為過原點的直線(橫軸或是縱軸)，表
示 X 愈 Y 財貨所得彈性等於一，恩格爾曲線為過原點的直線。
18.(B)；若 I r 愈大
r
Y

G  r [1  CYd (1  t1 )  I r ]  I r kY
(A)錯誤，FP 愈無效；
愈小
大
大
(B)正確；MP 愈有效；
Ir
Y

m  r [1  CYd (1  t1 )  I Y ]  I r kY
愈大
(C)錯誤，不管 I r 愈大或是 I r 愈小，只要在流動性陷阱下，MP 皆無效。
(D)錯誤，在流動性陷阱下，FP 有效；MP 完全無效。
19.(E);(A)政府支出增加，IS 曲線右移。(B)在 IS LM Model 假設 P 固定外生變數， G 增加
會造成 Y 增加， r 上漲，但是 P 不變。(D) IS LM Model 政府支出乘數會小於 Simple
Keynesian Model 政府支出乘數。(E)假設政府支出增加，搭配擴張性貨幣政策維持利
率不變，此時所得增加量恰好等於 SK Model 所以增加量。
20.(E)；21.(A)；22.(D)；23.(B)
24.(D)；25.(A)；26.(C)；27.(C)；28.(C)；29.(A)；
30.(B)；政府支出增加，所得增加，因 kY  0 使得貨幣需求增加，貨幣市場出現 Excess
Demand 現象，導致利率上漲，投資量減少，稱為「排擠效果」。
31.(C)；當政府實施預算赤字政策使得利率上漲，導致私部門消費量與投資量減少，會抵銷
財政政策有效性，稱為「排擠效果」。
32.(C)；當經濟體系處於流動性陷阱時，貨幣政策完全無效。
33.(B)；外國對本國產品偏好減少，使出口減少，將使 IS 曲線往左移。
本國對國外產品偏好增加，使進口增加，將使 IS 曲線往左移。
34.(C)
35.(B)；當邊際消費傾向提高時，會使 IS 曲線變更平坦。
36.(B); 當投資會受所得影響時，將使 IS 曲線變的更加平坦，但對 LM 曲線毫無影響。
37.(B);造成我國經濟衰退的主要原因來自於投資意願的降低與國際景氣低迷，使我國出口減
少，以上原因皆使 IS 曲線和 AD 曲線左移。
38.(D)；流動性陷阱下，只有財政政策最有效，貨幣政策完全無效。
39.(D)；投資對利率的變動愈不敏感投資的陷阱貨幣政策完全無效，財政政策完全有
效。
擴張性財政政策：政策有效
R
IS
IS 
擴張性貨幣政策：政策無效
R
IS
LM
Y*
Y
Y
LM
LM 
Y
Y
所以投資對利率的變動愈敏感投資陷阱的相反所以上述的結論也都相反（貨幣政策
完全有效，財政政策完全無效），答案為(D)。
40.(A)；邊際消費傾向愈大，財政政策與貨幣政策愈有效。
41.(B)；
r
Y

G  r [1  CY (1  t1 )  I Y ]  I r kY
Y
Ir

m  r [1  CY (1  t1 )  IY ]  I r kY
若 I r 愈大，貨幣乘數愈大  貨幣政策愈有效
政府支出乘愈小  財政政策愈無效
Y
Y
42.(D)； kY 愈大，
愈小，
愈小，表示財政政策與貨幣政策愈無效。
G
m
43.(D)； M Y 愈大，財政政策與貨幣政策愈無效。
44.(D)；財政政策係指政府支出與租稅工具。
45.(B)；流動性陷阱下，貨幣政策完全無效。
二、計算題︰一題 2 分
★(1-2)
Marshallian demand function
Max U  min{X , 2Y}
s.t
M  PX X  PY Y
X  2Y
均衡時 
 M  2PX Y  PY Y
M  PX X  PY Y
2M
M
∴ YM 
， XM 
2PX  PY
2PX  PY
(3)將普通需求函數 X M , Y M 代回直接效用函數，即可求出間接效用函數
 2M
2M 
U ( PX , PY , M )  min 
,

 2 PX  PY 2 PX  PY 
2M
∴ U
2 PX  PY
★(4-5)
Q *B 
Max U  min( aQ A , bQ B )
aQ  bQ B
bM
 A
∴ Q *A 
，
PA Q A  PB Q B  M
P
Q

P
Q

M
aP

bP
A
A
B
B

B
A
s.t
aM
aPB  bPA
 abM
abM 
(6)將 Q *A ， Q *B 代入直接效用函數可得： U  min 
,

 aPB  bPA aPB  bPA 
abM
abM
U
∴ U ( PA , PB , M ) 
aPB  bPA
aPB  bPA
★(7)Cobb-Douglas utility function：
x 財普通需求函數為 x M 
200 100
200 100

， yM 

2 Py
Py
2 Px
Px
(8)當 Px  5 時，x 財需求量 x *  20 ，則 x 財需求彈性為
d 
 dx Px 100 Px
 2 
1
dPx x
Px 100
Px
(9)原來組合： X 1  25 ， X 2  18 ， U 0  38
1
新組合： 38  4 (36) 2  X 2'  X 2'  14 ， X 2  4
小明要放棄 4 個蘋果，才可以維持原效用水準不變。
◙：
1
3
(10) MRS  
PX
 P  MRS  3
PY
(11) P  MRS 
1
3
無異曲線與預算線相切在拗折點，效用最大
預算線斜率比無異曲線較平坦階段(MRS＝
發生在無異曲線為拗折點之處
1/3)更平坦，效用最大均衡解發生在角隅解
效用極大化均衡解：
X  Y
 X *  Y *  20

2 X  Y  60
全部所得買 X 財： X  
60
 240
0.25
Y  0
◙(12): 正確；普通需求線上每一點都是消費者在預算限制條件下效用極大化最適選擇。
◙(13) MRS 
MU C 3

MUT 4
(14)無異曲線為直線，其 MRS 為常數，表示兩個財貨為完全替代品；
3 P
12
MRS   C  1  C *  0, T * 
 4；
4
P
3
T
(15)
MRS 
3 PC 2
12

  C* 
 6, T *  0 ；
4 PT 3
2
(16)
◙(17)：錯誤。
MUX MUY
MUX PX
MRSXY  2 



 應多買 Y 財，少買 X 財，才能提高效用。
PX
MUY PY
PY
◙(18)：消費者呈現完全替代型偏好，因此效用極大化為角解。
令：opera tickets 為 X，movie tickets 為 Y
MRS  5 
(19) MRS 
PX
MU X MUY
M 300
 10 

 X *  0, Y * 

 50
PY
PX
PY
PY
6
PX
 5 ；預算線與無異曲線重合，因此最適解有無限多組，預算線上每一點均為
PY
最適解。
◙(20)：利用恩格爾加總定理： i EMi  1  0.92 X  1.24 1   X   1   X  0.75
◙(21)無異曲線以(3，4)為飽合點之圓心，形成圓形，愈往圓心效用愈高，圖示如下：
X2
u 2  u1  u0
u
4
u0
0
u1
u2
X1
3
(22)由於消費者行為不符合單調性與凸性，使得無異曲線不一定為負斜率，在無異曲線為圓
形下，某些階段為負斜率、水平線、垂直線、正斜率。
(23)未必會將所得用盡：所得用盡之情況為 b 點，效用最大為 a 點，消費者追求效用極大化
之均衡點為 a 點，並未將所得用盡。
X2
b
a
4
u0
0
3
X1
◙(24)： 1  50%PX X  ( PY  5)Y  M  100
3
U
 25X 4 Y 3  0 ， MU Y  U Y  300X 4 Y 2  0
X
7
1
MU X  75 4 3
U Y
(26) U XX 
 600X 4 Y  0

X Y  0 ， U YY 
X
Y
4
1
◙(25) MU X 
表示 X 財符合邊際效用遞減法則；而 Y 財呈現邊際效用遞增現象。
3
(27) MRS XY
dY  MU X 25 X 4 Y 3
Y




 0 ，表示無異曲線為負斜率。
1
dX
MUY
12
X
4 2
300 X Y
X3
6 X  4Y  46
6 X  4Y  4 6
◙(28-29)： 

18  4( X  3)  4Y  46 X  3
4 X  4Y  4 0
Max U  XY
46
若X  3
 X* 
 3.83 
2 6
s.t
6X  4Y  46
Max U  XY
40
若X 3
 X* 
5
Y *  5  U *  25
2 4
s.t
4X  4Y  40
X3
X3
∴ 最適消費 X *  5 , Y *  5
◙(30)：
Max U  10 X 2Y
s.t. 2 X  Y  30
◙(31)： MRSxy 

1
1

47  6 y 23
 X *  10 ， Y *  10
MU x
1

MU y 47  6 y
；根據效用極大化一階必要條件可知: MRS xy 
 47  6y  23 ， y*  4
x* 
1
( M  Py y )  107  (23 4)  15
Px
Px
Py
x *  15
◙(32-33)：
 X：喜好品
 X：厭惡品
Y：喜好品
(13) 
y
Y：喜好品
y
u3
(
(
u2
汽
車
u1
u3
)
)
汽
車
(14) 
u2
u1
x (碳量)
1 3


4 4

Max
U

X
Y
◙(34) 
  X  200
 s.t. 10 X  10Y  8000
x
(節能減碳)
Y   600
(35)


 s.t.
1 3


Max U  X 4Y 4


  X  200（不合
10 X  10Y  8000, X  300 
Y   600  X   300
Y   500
台灣知識庫文教機構 2015 經濟學
適合系所：企研所、財金所、經研所
第四次大考
原就讀學校︰
考科組合：
學生姓名︰
一、選擇題︰一題 1 分
1.
6.
11.
16.
21.
26.
31.
36.
41.
2.
7.
12.
17.
22.
27.
32.
37.
42.
3.
8.
13.
18.
23.
28.
33.
38.
43.
4.
9.
14.
19.
24.
29.
34.
39.
44.
5.
10.
15.
20.
25.
30.
35.
40.
45.
二、填充題︰一格 2 分
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.