科目：經濟學原理與實習一
教授：駱明慶
試別：93學年度上學期期中考 (附解答)
時間：2004.11.22
----------------------------------------------------------------------
請在答案卷上清楚地標明題號
一、選擇題，回答正確選項即可，不需說明，每題3分，共30分
1. Metro North Railway is trying to decide whether or not to run an additional
train into New York City from New Heaven at 8:15 a.m. The total cost of
running trains between 8:00 a.m. and 9:00 a.m. is $45,000 and the expected
revenues on any given day are $100,000 during this time period. The cost
of running the additional train is $4,000 and it is expected that revenues
will rise to $104,500. Metro North should
(a) run the train because the total revenues are greater than the total costs.
(b) not run the train because the total costs are already too high.
(c) run the train because the marginal cost is less than the marginal revenue.
(d) not run the train because the marginal cost is greater than the marginal
revenue.
2. In the marketplace, John voluntarily sells his last two loaves of bread to
Mary for $2. We can infer that this will benefit
(a) both John and Mary.
(b) Mary, but not John, since these are John's last two loaves of bread.
(c) Mary, while imposing a cost on John equal to the benefit Mary receives.
(d) neither John nor Mary.
3. If a drought destroyed half of the U.S. garlic crop at a time when the
health benefits of garlic were being well publicized, economists would
expect that in the market for garlic
(a) quantity exchanged would rise but the change in price is uncertain without
further information.
(b) price would rise but the change in quantity exchanged is uncertain without
further information.
(c) both price and quantity exchanged would rise.
(d) price would rise and quantity exchanged would fall.
4. If the fines and jail time for dealing illegal drugs were reduced, we would
expect
(a) an increased demand for illegal drugs.
(b) an increased supply of illegal drugs, a lower price, and higher quantity
traded.
(c) a decreased supply of illegal drugs, a higher price, and lower quantity
traded.
(d) no change in the market for illegal drugs because buyers and sellers
believe they won't get caught.
5. Rent controls typically end up
(a) increasing rents received by landlords.
(b) raising property values.
(c) encouraging landlords to overspend for maintenance.
(d) discouraging new housing construction.
6. Suppose demand for electricity is perfectly inelastic. A tax on electricity
will be
(a) split between producers and consumers in equal shares.
(b) paid only by producers.
(c) paid only by consumers.
(d) split between producers and consumers in unequal shares.
7. Many U.S. producers complain about limited access to the Japanese market.
They say that they cannot export to Japan because Japanese import
restrictions are so severe. Who gains? Who loses?
(a) Everyone loses.
(b) Japanese producers gain, U.S. producers and Japanese consumers lose.
(c) Japanese producers and consumers gain, U.S. producers and consumers lose.
(d) Japanese consumers and U.S. consumers gain, Japanese producers lose.
8. A dentist shared an office building with a radio station. The electrical
current from the dentist's drill causes static in the radio broadcast,
causing the radio station to lose $10,000 in discounted future profits.
The radio station could put up a shield at a cost of $30,000; the dentist
could buy a new drill that causes less interference for $6,000. Either
would restore the radio station's lost profits. What is the economically
efficient outcome?
(a) The radio station puts up a shield, which it pays for.
(b) The radio station puts up a shield, which the dentist pays for.
(c) The radio station does not put up a shield and the dentist does not buy a
new drill.
(d) The dentist gets a new drill and it does not matter who pays for it.
9. The commercial value of ivory is a threat to the elephant, but the
commercial value of beef is a guardian of the cow. This is because
(a) the cow is raised in developed economies while the elephant lives primarily
in less-developed nations.
(b) cows are private goods while elephants tend to roam without owners.
(c) cows and elephants are public good, but ivory is nonrival.
(d) ivory is nonrival and nonexclusive but beef is rival and exclusive.
10. A tax that is higher for men then for women violates the criterion of
(a) diagonal equity.
(b) linear equity.
(c) vertical equity.
(d) horizontal equity.
二、非選擇題，共70分。答題時請務必簡潔，並適當說明你的想法。
1. (25分) 簡答下列問題。
(a) (5分) 在一個生意興隆的餐廳裡，「二手煙」和「哭鬧的小孩」有何相似之處？
(b) (5分) 「再見了，可魯」是一部描寫導盲犬的溫馨電影，賣座相當好的結果，將使得
拉不拉多犬(可魯的品種)和體型嬌小的吉娃娃犬，其幼犬在寵物市場上的價格分別
如何變化？
(c) (5分) 就政府的角色而言，「流浪教師」的現象和「最低工資」(minimum wage)有何
相似之處？
(d) (5分) 請由是否為excludable和是否為rival的角度，判斷「全民健保」屬於何種
goods？這種goods通常有何問題？
(e) (5分) 幾乎所有研究都顯示，我國學生升大學與否，和學生的家庭背景，如父母教育
程度或家庭所得都成正相關。另一方面，在「低學費」政策之下，公立大學的學費之
所以便宜，並不是大學教育的成本低廉，而是政府高度補貼的結果。請評論以下敘述
「大學教育有正的外部性，因此政府應該高度補貼公立大學生的學費。」
2. (15分) 阿豪對光泉牛奶的需求表如下。
-----------------
價格 需求量
-----------------
5 5
10 4
15 3
20 2
25 1
-----------------
(a) (5分) 當牛奶價格為每瓶20元時，阿豪的消費量為何？此時他共花了多少錢喝牛奶？
(b) (5分) 承上題，若超市以3瓶54元進行促銷活動，在仍然可以用每瓶20元的價格購買的
情況之下，阿豪會以54元購買3瓶嗎？為什麼？
(題示:由消費者剩餘的角度考慮此問題。)
(c) (5分) 承(a)，若超市招募會員，只要付入會費8元，就能夠用每瓶15元的價格購買牛
奶，請問阿豪會加入會員嗎？為什麼？
3. (15分) Suppose that a market is described by the following supply and demand
equations:
Qs = 2P
Qd = 300-P
(a) (2分) Solve for the equilibrium price and the equilibrium quantity.
(b) (3分) Suppose that a tax T = 60 is placed on buyers, so the new demand
equation is
Qd = 300-(P+T) = 300-(P+60).
Solve for the new equilibrium. What happens to the price received by
sellers, the price paid by buyers, and the quantity sold?
(c) (4分) From (b), caculate the tax revenue and deadweight loss of the tax?
(d) (3分) Instead of placing the tax on buyers, suppose a tax T = 60 is placed
on sellers, what is the new supply equation? (Hint:You don't need to
answer this part correctly to solve part (e).)
(e) (3分) From (d), solve the new equilibrium, what is the price received by
sellers, the price paid by buyers, and the quantity sold?
4. (15分) 假設T國之汽車供給來源包括國產車及進口車兩種，國產車的供給函數為
Qs = P
國外廠商則願意在以30元的價格供給任何數量的汽車。此外，汽車的需求函數為
Qd = 100-P
(a) (3分) 請畫出汽車市場的總供給線。
(b) (3分) 計算均衡時之價格以及進口數量。
(c) (3分) 假設政府為了保護國內汽車產業，決定對進口車課以每輛10元之關稅，請問均
衡時的價格與進口數量變成多少？
(d) (3分) 承(c)，這10元的關稅有多少轉嫁給消費者？
(e) (3分) 假設政府放棄關稅而改採取進口配額，並限制最多只能有20輛車從國外進口，
請問此時均衡價格為何？
==================================================================
經濟學原理一 期中考解答 2004.11.22
一、選擇題
1.c 2.a 3.b 4.b 5.d 6.c 7.b 8.d 9.b 10.d
二、非選擇題
1a 兩者都產生負的外部性。
1b 電影的熱賣，造成對拉不拉多犬的需求增加，價格提高。至於屬於替代品的吉娃娃犬
則需求減少，價格下降。
1c 兩者都是因為政府訂定一個高於市場均衡的價格，使得供過於求。「流浪教師」是政府
在中小學教師的勞動市場上，給予老師明顯高於其他行業的待遇，使得想成為老師的人數
，遠多於教師的職缺。「最低工資」則是政府要求雇主支付高於市場均衡水準的工資造成
勞動供給大於勞動需求。
1d 「全民健保」投保者皆可使用醫療資源，但個人的使用會排擠他人的醫療資源，因此
「全民健保」不是excludable，但是rival。所以，「全民健保」是一種common resources
，通常會有被過度使用的問題。
1e 雖然許多人同意「教育有外部性」的說法，但是文獻上並沒有足夠的證據證明大學教育
真的有外部性。即使大學教育真的有「正的外部性」，這只說明了大學生總數較「社會最
適」的大學生數目為低，應該有更多的人讀大學。因此，學費補貼的對象應該是處於「讀
與不讀」或是錄取邊緣的學生，而不是考試分數較高，家庭背景較好的公立大學學生。對
於國立大學的學生而言，由於家庭環境較好，即使不補貼學費，也不會影響他們就讀大學
的決策。因此，對公立大學高度補貼的所謂「低學費政策」，是沒有道理的。
2a 2瓶，40元。
2b 本題的作法是比較(1)每瓶20元買兩瓶 (2)54元買3瓶，這兩種情況的消費者剩餘，阿豪
將選擇消費者剩餘較大的選項。
(1)價格為每瓶20元時，阿豪會花40元買2瓶，但他對這2瓶牛奶的願付價格為25+20=45
元。因此，消費者剩餘為5元。(2)在促銷活動下，特價品3瓶的價格為54元，這3瓶牛奶對
阿豪的價值為25+20+15=60元，此時消費者剩餘為60-54=6元，大於單價20元買2瓶時的消費
者剩餘。因此，阿豪會以54元買3瓶。
2c 同上，這裡要比較的是(1)每瓶20元買2瓶和(2)入會費8元，每瓶15元，兩種情況下的消
費者剩餘。
價格15元時，由需求表知阿豪會花45元買3瓶，加上入會費，阿豪共花了8+45=53元，阿
豪對3瓶牛奶的願付價格是60元，消費者剩餘為7元。比以20元單買2瓶時的消費者剩餘-5元
多，因此阿豪會加入會員。
3a P* = 100 , Q* = 200 .
3b Let Qs = 2P = Qd = 300-(P+60), → Q* = 160. The quantity sold is 160, price
received by sellers is 80, and the price paid by the buyers is 140.
3c Tax revenue is T x Q = 60 x 160 = 9600. Deadweight loss is 1/2 x T x ΔQ =
1/2 x 60 x (200-160) = 1200.
3d From the usual demand-supply graph where we put price in the vertical axis
and quantity in the horizontal axis, the supply equation is P = 1/2Q. Since
placing a tax of T on sellers will shift the supply curve upward by T, the new
supply equation is P = T + 1/2 Qs. Therefore, the new supply equation is
Qs = 2(P-T) = 2P-120
3e Since it is known that whether a tax is placed on buyers or is placed on
sellers does not affect the tax incidence. The price received by sellers, the
price paid by buyers, and the quantity sold are the same as the ansewers in (b)
We can check this result. Since the new supply function is Qs = 2P-120, and
the demand function is Qd = 300-P. Let 2P-120 = 300-P, the price buyers paid
is 140. The quantity sold is 2x140-120 = 160, and the price sellers received
is 140-60 = 80.
4a 汽車的總供給線為國內廠商與國外廠商供給線的水平加總。本題要注意的是國外廠商的
供給線是一價格為30元的水平線，國內廠商因此不會在價格高於30元以上時生產，總供給
線為如下的一個拗折供給線。
當價格低於30時，供給線為Qs = P，當價格等於30時，供給線為一水平線，此時供給彈
性無限大。
4b 此題可直接由供給線與需求現的交點看出，均衡價格為30元。另一個思考的方式是，首
先確認均衡價格絕不會高於30元，因為國外廠商願意以30元之價格提供任何數量。其次，
當價格低於30元時，國外供給量為零，國內供給量最多為30輛，但此時需求量至少70輛，
所以 P < 30 不會是均衡價格。因此均衡價格必然是30元，進口數量為需求量與國內供給
量之差，70 - 30 = 40 輛。
4c 進口車課以每輛10元的關稅之後，進口車的價格變為40元。同上題的推理，若價格低於
40元，進口量為0，國內供給量最多為40輛，但此時需求至少60輛，必須賴進口以滿足國內
需求。因此，均衡價格為40元，進口數量為60-40 = 20。
4d 關稅使價格上漲10元，10元的關稅完全轉嫁給消費者，因此此時供給彈性為無限大。
4e 如果沒有進口車，國內價格必須高達50元(Qs = P = Qd = 100-P)才能使市場達於均衡
。但在價格往50元調整的過程中，外國車可以用30元的價格進口，由(b)已知，沒有進口配
額時，價格為30元，進口數量需為40輛才能達於均衡。因此，在進口配額只有20量的情況
下，價格還會繼續上漲，直到需求量與國內供給之差等於20輛時，此時價格為40元，國內
供給量為40輛，需求量為60輛。
本題的進口配額，恰與(c)中課徵關稅時的進口數量相同，使得採取「10元關稅」和
「進口配額20輛」的政策效果完全相同。
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 59.121.216.39
※ 編輯: TINTINH 來自: 59.121.216.39 (10/13 20:25)