The firm faces the following demand curve: Price ($) Quantity To maximize profit (or minimize losses), the fi

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1 經濟學原理與實習一第二次小考 11/03/2014 請以學校答案紙作答, 寫兩張以上者請對折請寫上學號系級姓名, 否則不予計分作答時請清楚標明題號一選擇題 (45%): 不用解釋 1. (3 points) If Farmer Brown plants no seeds on his farm, he gets no harvest. If he plants 1 bag of seeds, he gets 5 bushels of wheat. If he plants 2 bags, he gets 9 bushels. If he plants 3 bags, he gets 12 bushels. A bag of seeds costs $120, and seeds are his only cost. Farmer Brown s totalcost curve is A. increasing at an increasing rate. B. increasing at a decreasing rate. C. increasing at a constant rate. D. decreasing. 2. (3 points) Robin owns a horse stables and riding academy and gives riding lessons for children at pony camp. Her business operates in a competitive industry. Robin gives riding lessons to 20 children per month. Her monthly total revenue is $4,000. The marginal cost of pony camp is $100 per child. In order to maximize profits, Robin should A. give riding lessons to more than 20 children per month. B. give riding lessons to fewer than 20 children per month. C. continue to give riding lessons to 20 children per month. D. We do not have enough information to answer the question. 3. (3 points) For a monopoly, the level of output at which marginal revenue equals zero is also the level of output at which A. average revenue is zero. B. profit is maximized. C. total revenue is maximized. D. marginal cost is zero. 4. (3 points) A monopolistically competitive firm has the following cost structure: Output Total Cost($)

2 The firm faces the following demand curve: Price ($) Quantity To maximize profit (or minimize losses), the firm will produce A. 20 units B. 30 units C. 40 units D. 50 units 5. (3 points) Which of the following conditions is characteristic of a monopolistically competitive firm in short-run equilibrium? A. P > ATC B. P = ATC C. P < ATC D. Any of the above could be correct. 6. (3 points) Senator Hubris wants to pass a law that would require all monopolistically competitive firms to operate at their efficient scale. If this law were to pass and be enforced, we would expect that monopolistically competitive firms would A. see their profits increase. B. break even. C. lose money. D. not really be affected by the law. 7. (3 points) Assume that a local restaurant sells two items, salads and steaks. The restaurant s only two customers on a particular day are Mr. Carnivore and Ms. Leafygreens. Mr. Carnivore is willing to pay $20 for a steak and $7 for a salad. Ms. Leafygreens is willing to pay only $8 for a steak, but is willing to pay $12 for a salad. Assume that the restaurant can provide each of these items at zero marginal cost.how much additional profit can the restaurant earn by switching to the use of a tying strategy to price salads and steaks rather than pricing these goods separately? A. $20 B. $12 C. $7 D. $6 Page 2

3 8. (3 points) George and Jerry are competitors in a local market. Each is trying to decide if it is better to advertise on TV, on radio, or not at all. If they both advertise on TV, each will earn a profit of $3,000. If they both advertise on radio, each will earn a profit of $5,000. If neither advertises at all, each will earn a profit of $10,000. If one advertises on TV and the other advertises on radio, then the one advertising on TV will earn $4,000 and the other will earn $2,000. If one advertises on TV and the other does not advertise, then the one advertising on TV will earn $8,000 and the other will earn $5,000. If one advertises on radio and the other does not advertise, then the one advertising on radio will earn $9,000 and the other will earn $6,000. If both follow their dominant strategy, then George will A. advertise on TV and earn $3,000. B. advertise on radio and earn $5,000. C. advertise on TV and earn $8,000. D. not advertise and earn $10, (3 points) Harry owns a snow-removal business. He hires workers to shovel driveways for him during the winter. The first worker he hires can shovel twelve driveways in one day. When Harry hires two workers, they can shovel a total of 22 driveways in one day. When Harry hires a third worker, he shovels an additional eight driveways in one day.what is the total productivity of three workers? A. 12 B. 22 C. 30 D (3 points) Refer to the previous question. Suppose that Harry pays each worker $80 per day and that he charges each customer $20 to have his driveway shoveled. What is the value of the marginal product of labor for the third worker? A. $160 B. $640 C. $1600 D. $ (3 points) Which theory is supportive of the idea that increasing educational levels for all workers would raise all workers productivity and therefore their wages? A. the theory of compensating differentials. B. the efficient-market hypothesis. C. human-capital theory. D. signaling theory. Page 3

4 12. (3 points) Suppose that a small county is considering adding a guard rail to a dangerous curve by a river. The guard rail will cost $70,000. The average damage done to vehicles that slide off the road at the curve is $10,000. It is expected that the guard rail will prevent 5 vehicles from sliding off the road during its usable life. What should the county do? A. Install the guard rail because safety is priceless. B. Install the guard rail because the benefits exceed the costs. C. Do not install the guard rail because the costs exceed the benefits. D. Do not install the guard rail at any cost because drivers can purchase private insurance for their vehicles. 13. (3 points) Which of the following statements about a production function is correct for a firm that uses labor to produce output? A. The production function depicts the relationship between the quantity of labor and the quantity of output. B. The slope of the production function measures marginal product. C. The slopes of the production function and the total cost curve are inversely related; if one is increasing, the other is decreasing. D. All of the above are correct. 14. (3 points) Susan quit her job as a teacher, which paid her $36,000 per year, in order to start her own catering business. She spent $12,000 of her savings, which had been earning 10 percent interest per year, on equipment for her business. She also borrowed $12,000 from her bank at 10 percent interest, which she also spent on equipment. For the past several months she has spent $1,000 per month on ingredients and other variable costs. Also for the past several months she has earned $4,500 in monthly revenue. In the short run, Susan should A. shut down her business, and in the long run she should exit the industry. B. continue to operate her business, but in the long run she should exit the industry. C. continue to operate her business, but in the long run she will probably face competition from newly entering firms. D. continue to operate her business, and she is also in long-run equilibrium. 15. (3 points) When a firm is experiencing diseconomies of scale, long-run A. average total cost is minimized. B. average total cost is greater than long-run marginal cost. C. average total cost is less than long-run marginal cost. D. marginal cost is minimized. Page 4

5 二非選擇題 (55%): 答題時請適當說明你的想法, 答案內容以讓批改者瞭解為原則 1. (10 points) 是非不定題, 請回對錯不一定並解釋 (a) (3 points) 完全競爭市場 (competitive market) 的市場需求曲線一定是水平線 (b) (3 points) 在獨占市場 (Monopoly) 第一級差別取價下 (price discrimination), 價格 (price) 會等於平均收益 (average revenue) (c) (4 points) 完全競爭市場 (competitive market) 中, 具有成本優勢的廠商可利用降低價格的策略來逼使成本較高的廠商退出 2. (20 points) 老陶和袁老闆在同一片草原上放牛草原上的乳牛愈多, 每頭牛能吃到的牧草愈少, 牛奶產量也愈低每頭牛產乳量 (q) 與牛隻數 (N) 的關係為 q = N 牛奶價格為 $1, 飼養每頭乳牛的成本為每頭 $10 老陶和袁老闆各有兩個選擇 : 養 30 頭牛或養 40 頭牛 (a) (4 points) 本題中, 草原對兩人而言是私有財, 公共財, 還是共有資源? (b) (4 points) 請用賽局矩陣描述本題情境 (c) (4 points) 請問袁老闆是否有優勢策略 (dominant strategy)? (d) (4 points) 請找出 Nash 均衡此一均衡是否有效率? (e) (4 points) 袁老闆最多願意花多少錢購買老陶在草原放牛的權利?( 老陶若將權利賣給袁老闆, 他就不能在草原上放牛, 而袁老闆可以再多養 30 或 40 頭牛 ) 如果兩人能夠交易放牧的權利, 結果是否會有效率? 3. (10 points) 假設在某座山樵夫數量為 N(N 為正整數 ) 時, 每天每人能砍伐的木材噸數為 20-2N 每位樵夫的機會成本為 4 噸木材, (a) (3 points) 有多少樵夫會來砍樹? 總共砍了多少樹? 此時這座山對社會的總剩餘為何? (b) (3 points) 由社會的角度而言, 來這座山砍樹的最適人數為何? 此時總剩餘多少? (c) (4 points) 若這座山是助教所有, 助教應收多少噸的木材當入場費, 使這座山的使用達社會效率? 4. (15 points) 假設巧克力市場是完全競爭市場, 成本固定產業現在市場已達長期均衡 (a) (3 points) 今天政府對巧克力生產商課定額稅, 請問在短期之下, 市場價格與交易量會如何變化 (b) (4 points) 承上題, 此時廠商是否有利潤? 在利潤極大化的產量下平均成本與邊際成本何者較大? (c) (4 points) 在長期之下, 跟課稅前相比, 市場價格與交易量會如何變化 (d) (4 points) 承上題, 此時廠商是否有利潤? 在利潤極大化的產量下平均成本與邊際成本何者較大? Page 5

6 Solution: 一選擇題 1. A.increasing at an increasing rate. 因為邊際產量遞減, 表示表示每多生產一單位必須投入更多要素, 也就必須投入更多成本 2. A. give riding lessons to more than 20 children per month. 在 20 單位時,MR=200,MC=100, 收第 21 人時 profit 會再增加 3. C. total revenue is maximized. 下一單位的 MR 將是負的, 故此時為 TR 極大值 4. B.30 units 20 至 30 單位的 MR 為 $180,MC 為 $ 至 40 單位的 MR 為 $20,MC 為 $ D. Any of the above could be correct. 在短期下廠商可能獲利或虧損, 故選 D 6. C. lose money. 7. D. $6 分開定價時牛排賣 $20, 沙拉賣 $7 利潤最大, 此時利潤為 $34 套裝訂價時牛排與沙拉的套餐定價 $20 利潤最大, 此時利潤 $40 8. D. not advertise and earn $10, C.30 Jerry none TV radio George none (10000,10000) (5000,8000) (6000,9000) TV (8000,5000) (3000,3000) (4000,2000) radio (9000,6000) (2000,4000) (5000,5000) 10. A.$ C.human-capital theory. 12. C. Do not install the guard rail because the costs exceed the benefits. Page 6

7 13. D. All of the above are correct. 14. C. continue to operate her business, but in the long run she will probably face competition from newly entering firms. 每個月的固定成本是 ($36000+$ )/12=$ C.average total cost is less than long-run marginal cost. 二非選擇題 1. (a) 錯, 一定是水平線的是個別廠商所面對的需求曲線, 因為廠商為 price-taker (b) 第一級差別取價下 P=MR, 因為多賣一單位前面的單位不需降價 (c) 不能, 每個廠商都是 price-taker, 個別廠商降價不影響市場價格 2. (a) 共有資源 (b) 袁老闆老陶養 30 頭養 40 頭養 30 頭 ( 900, 900) (750, 1000) 養 40 頭 (1000, 750) (800, 800) (c) 給定老陶養 30 頭牛, 袁老闆養 30 頭利潤為 $900, 養 40 頭利潤為 $1,000; 給定老陶養 40 頭牛, 袁老闆養 30 頭利潤為 $750, 養 40 頭利潤為 $800; 不論老陶養 30 或 40 頭牛, 袁老闆養 40 頭牛的利潤皆高於養 30 頭牛, 養 40 頭牛為其優勢策略 (d) Nash 均衡為兩人都養 40 頭牛此時總剩餘為 $1,600, 但兩人各養 30 頭牛時總剩餘為 $1,800, 因此均衡無效率 3. 樵夫人數平均噸數總噸數總剩餘 (a) 8 人,32 噸,0 (b) 4 人,32 噸 (c) 8 噸, 此時才能避免第 5 人進去砍樹 ( 如果不限制使助教利潤最大, 則大於 6 噸, 小於或等於 8 噸的答案都可以 ) Page 7

8 4. AC=FC+VC, 課定額稅 FC 上升, 故 AC 上升但課定額稅後每單位增加之成本並不變, 故 MC 不變 ( 見下圖 ) Figure 1: (a) 課定額稅不影響 MC( 個別廠商供給曲線 ), 且短期不能自由進出, 故市場供給曲線不變可知市場均衡不會改變 (b) 廠商會虧損極大化利潤產量在 q, 此時 AC>MC (c) 長期之下有廠商會退出, 供給減少, 價格上升, 交易量下降 (d) 廠商無利潤, 在 AC 最低點生產 (q ), 故此時 AC=MC Page 8

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第十七章本章欲探討底下問題 : 獨佔性競爭何謂獨佔性競爭? 其與完全競爭及獨佔的關係為何? 獨佔性競爭的均衡獨佔性競爭與社會福利廣告獨佔性競爭 Monopolistic competition: 一種出售類似產品廠商數目眾多的市場結構, 其中