解 :(D); 獨占廠商之最適決策 :MR=MC 且 P>MC 7. A monopolist that operates along the elastic range of its demand will find that (A) total revenue increases when pr

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1 第9章 獨占市場. Monopoly results because of (A) barriers to entry into the industry (B) greed by the seller (C) lack of interest by potential competitors (D) inadequate regulation by government (E) all of the above. 96 台大國企所 (E) 獨占廠商產生的原因 主要來自於市場具有進入障礙 使得新廠商無法進入所導致 而以上因素 皆可能形成進入障礙.請說明為何在均衡狀態下 獨占廠商的產出水準是座落於需求曲線價格彈性大於一的地方 95 解 進行 single price policy 且 MC 0 的獨占者而言 其必在 E d 之處進行生產 MR MC 0 P Ed d 0 E. $ MC AC 6 4 AR MR 4 Q 6 若需求曲線為 P a bq 請問下列敘述何者為正確 Ⅰ.MR 曲線的斜率為 AR 曲線斜率的 倍 Ⅱ.MR 曲線一定會平分 AR 曲線的橫軸截距 Ⅲ.MR = 0 時之需求量所對應之需求曲線上的點彈性值為 (A)Ⅰ (B)Ⅰ Ⅱ (C)Ⅰ Ⅲ (D)Ⅰ Ⅱ Ⅲ (E)以上皆錯誤 96 北大經研所 解 (B) 需求曲線 p a bq Ⅰ. 此為正確敘述 AR P a bq P TR ARQ aq bq dtr MR a bq dq Ed MR 曲線斜率為 AR 的 倍 0 Ⅱ. 此為正確敘述 MR 曲線平分 AR 曲線橫軸截距 MR AR Q Ⅲ. 此為正確敘述 MR = 0 時的 Q 對應 AR 曲線上需求彈性為 4.For the unregulated, single-price monopoly shown in the figure above, when its profit is maximized, output will be (A) 6 units per year and the price will be $4. (B) 4 units per year and the price will be $4. (C) 4 units per year and the price will be $6. (D) None of the above answers is correct. 95 解 (C) 獨占廠商利用 MR MC 決策 Q 4 在透過市場需求線定價 P 6 5. A monopolist maximizes profits by producing a level of output where: (A) P=MC. P.> MC (D) P < MC. 95 (B) P=AC (C) 解 (C) 獨占廠商之最適決策 MR MC P MC 6. At the profit maximizing level of output for a monopolist: (A) P = MR and AC = MC. (B) P = AR and AR = AC (C) P = MC and MR > MC. (D) P > MC and MR = MC. 95

2 解 :(D); 獨占廠商之最適決策 :MR=MC 且 P>MC 7. A monopolist that operates along the elastic range of its demand will find that (A) total revenue increases when price decreases. (B) total revenue decreases when price decreases. (C) marginal revenue is negative (D) it is more profitable to operate along the inelastic range of the demand curve. 95 解 :(A); TR d TR Q( E ) MR P TR, 在 E d > 下, 且 MR > 0 d 0 P Q E P 8. Monopolies can earn an economic profit in the long run because of (A) rent seeking by competitors. (B) the elastic demand for the monopoly s product. (C) the cost savings gained by the monopoly. (D) barriers to enter the monopoly s market. 95 解 :(D); 獨占廠商在長期均衡下能賺取超額利潤的主要原因, 來自進入障礙的保障 9. 下列有關獨占市場之敘述, 何者正確? (A) 因為對生產要素取得絕對控制權, 此類獨占稱為自然獨占 (B) 在均衡狀態下, 獨占廠商產出水準會落於需求曲線價格彈性小於 之處 (C) 獨占廠商若在兩個不同需求彈 性市場, 採差別取價時, 若需求彈性市場較小者, 其價格應訂較低 (D) 獨占廠商將生產至邊際收益等於邊 際成本之產出水準 95 解 :(D) 0.If the demand for its product is elastic, a monopoly s (A) marginal revenue is zero. (B) total revenue decreases when the firm lowers its price. (C) marginal revenue is positive. (D) total revenue is unchanged when the firm lowers its price. 95 解 :(C); 在 E d >,MR > 0 且 TR 為遞增. 假設某獨占廠商在利潤最大時的需求彈性為, 邊際收益為 $00, 試問其利潤最大的定價為多少? (A) $50 (B) $00 (C) $600 (D) $50 95 d E 解 :(C); 依據 mark-up pricing: MR MC 00 P 00 P d d E E. 下列敘述何者有誤? (A) 反獨占的政策目的為限制獨立力的濫用 (B) 我國的反獨占法為消費者保護法 (C) 制定反獨占法是為了阻止不公平競爭行為的發生 (D) 常用來規範獨占的工具為 政府管制 和 反獨 占 法 95 MR P d E 解 :(B); 我國的反獨占法為公平交易法. 獨占廠商之短期供給曲線為 : (A)AVC 最低點以上之 MC 線段 (B)AFC 最低點以上之 MC 線段 (C)AC 最低點以上之 MC 線段 (D) 以上皆非 95 解 :(D); 獨占廠商的供給曲線不存在 4. 假設一獨占廠商之需求函數為 Q=400-0P, 而其總成本函數則為 TC=5Q+Q /50, 其利潤最大之訂價為 : (A)87 (B)4.65 (C)07 (D)9. (E) 以上皆非 95 解 :(B); P 0 Q MR 0 Q MC 5 Q MR MC 0 0.Q Q Q* 07.4, P* A monopoly s marginal cost will likely (A) exceed its marginal revenue. (B) equal average total

3 cost. (C) be less than average fixed cost. (D) be less than the market price of its goods. 95 解 (D) 獨占下 廠商追求利潤最大 P = MR > MC 6.Characteristics of a Monopoly include: () sole seller of its product. () product does not have close substitutes. () generates large economic profits. (4) is located in a small geographic market. (A) (), (), and (4). (B) both (), (). (C) both () and (). (D) all of the above. 95 解 (C) 獨占下只有一個賣者 且生產獨特產品(沒有近似的替代品) 至於利潤則不一定 也可能會有虧 損 7.Patent and copyright laws are major sources of (A) resource monopolies. (B) natural monopolies. (C) government-created monopolies. (D) none of the above. 95 解 (C) 專利權 版權這是人為獨占(政府創造出來的) 8. The fact that a single-price monopolist must lower its price to sell more output explains why price exceeds marginal revenue. 95 銘傳管研所 解 對 MR P Q dp dq dp 0 P MR dq if dp 獨佔廠商面對負斜率需求線 0 必然P MR dq 9. In the short run, profit maximization typically occurs where total revenue is at its maximum. 解 錯 max MR MC, if MC 0, 廠商必在TR遞增處生產 95 銘傳管研所 0. A monopoly produces widgets at a marginal cost of $0 per units and zero fixed costs. It faces an inverse demand function given by P = 50 Q. Suppose fixed costs rise to $400. What happens in the market? (A) The firm will raise the price. (B) The firm will shut down immediately. (C) The firm continues to produce the same output and charge the same price. (D) The firm will reduce its output and raise price. 96 輔大管研所 解 C Max π=(50-q)q 0Q F.O.C 50 Q 0 Q* 0 P*=0 d S.O.C dq < 0 繼續生產條件 P*=0 > AVC(Q*)=0 在廠商最適決策為 Q* 0 且 P* 0 下 固定成本提高將不影響廠商的最適產量與訂價. The deadweight loss from monopoly results from (A) The higher price charged and quantity produced compared to competition. (B) The fact that price and marginal revenue are not the same. (C) Profit maximization as a motivation factor. (D) Irrational action on the part of consumers. (E) Marginal cost being upward sloping. 96 輔大管研所 解 (B) 獨占廠商由於具有 P MP 的特性 使得 MR MC 下的社會福利水準小於 P MC 下的社會福利 水準而產生 deadweight loss.單一價格獨占者 Monolith 公司的首席執行長陶醉於權力中 假設他能夠隨心所欲訂定價格 並能在該 價格下賣出任何願意出售的數量 她的想法正確嗎 理曲 95 銘傳管研所

4 解 錯 max MR MC.The marginal cost of a monopolist is $50 and the market demand is P 0 4Q. ()What will be the market price and the production level? ()What will be the revenue and profit of this monopolist? () If the government deregulates this industry and turns it into a perfectly competitive market, then what will be the market price and production level? (4) How much is the deadweight loss for this industry under a monopoly? 96 高雄第一科大金融營運所 解 獨占廠商的利潤極大化決策 Max TR(Q) TC(Q) d dtr dtc F.O.C 0 0 MR MC dq dq dq S.O.C d d TR d TC dmr dmc MR斜率 MC斜率 dq dq dq dq dq () 獨占廠商採取單一訂價法 TR PQ 0Q 4Q MR dtr 0 8Q dq Q單 0 MR MC 0 8Q 50 P單 0 4 Q單 0 TC MCdQ 50dQ 50Q 單 P單 Q單 50Q單 TR單 P單 Q單 600 () 政府採取 P MC 管制法 Q管 40 P 0 4Q MC 50 P管 MC 50 管 P管 Q管 50Q管 0 政府採取 P MC 管制法之下 獨占廠商不存在超額利潤 () 獨占下的無謂損失 DWL (40 0) (0 50) 800 $ 0 0 P=AR=0-4Q 無謂損失 MC 50 0 MR 6.5 Q Price Quantity

5 The table above gives the demand schedule for water bottled by Wanda's Healthy Waters. If Wanda's is a monopoly and maximizes its profit, what is the range of possible prices at Wanda's will sell water? (A)at only $8 a bottle (B)any price over $8 a bottle (C)any price below $8 a bottle (D)at only $6 a bottle 96 嘉大管研所 解 :(B); P=6-Q MR=6-4Q 當 Q=4 且 P=8 時 MR=0, 由於獨占廠商在 single price policy 下 必在 Ed 5 之處進行銷售, 因此其最適訂價必在 P 8 的階段 5.A monopolist maximizes profits by producing a level of output where(a)p=mc.(b)p=ac. (C)P>MC.(D)P<MC. 94 彰師企研所 解 :(C); 獨佔廠商利潤極大化決策 MR=MC 時, 保證 P>MC 6.In the short run, a monopolist(a)will never shut down.(b)will shut down if price equals average total cost.(c)will shut down if price is less than average total cost.(d)will shut down if price is less than average variable cost. 94 彰師企研所 解 :(D); 獨佔廠商短期歇業點 :TR<TVC 時, 短期選擇歇業停工不生產 7. 某獨占產品市場之需求函數為 Q = 500 5P, 總生產成本函數為 C = 0Q +50 獨占廠商的最適定價為 (A) 5 (B) 5 (C) 45 (D) 55 (E) P 00 Q MR 00 Q MR MC 00 Q 解 :(D); Q 5, P 00 Q 中臺公司 為灰胡桃加工業, 一個完全競爭產業的小廠商, 灰胡桃一單位之市場價格為 $640, 中臺公司 之成本曲線如方程式 :TC = $40Q-$0Q+$0Q, 成本方程式中包括了正常利潤, 中臺公司 獲得最大利潤時 : (A) 利潤為 $8000,AC =$0,Q=40 (B) 利潤為 $8000,AC =$40,Q=0 (C) 利潤為 $8000, AC =$0,Q=0 (D) 利潤為 $8000,AC =$0,Q=0 (E) 利潤為 $6000,AC =$00,Q=0 (F) 以上皆非 95 解 :(B); Max 640Q 4Q 0Q Q F.O.C: Q Q Q Q 0Q 0 0 Q 0 0 S.O.C: 40 6Q Q AC 40 0Q Q 40 在 Q 0 下, 80 0, 故 Q 0 為利潤極大化之產量 Q 假設 廣源公司 之總成本曲線改變為 :TC =00+Q+0.Q, 請問 廣源公司 最適價格 數量是有所改變? 若改變, 最適價格 數量為何? (A) 未改變 (B) P=$.8,Q=6.6 (C) P=$6.6,Q=.8 (D) P=$6.6,Q=.8 (E) P=$.8,Q=6.6 (F) 以上皆非 95 解 :(D); 在 Q<50 時 : MR MC 0 0.Q 0. 6Q Q. 75 ( 合 ) 在 Q>50 時 : MR MC Q 0. 6Q Q 0. 8 ( 不合 )

6 故最適產量為 Q.75, 此時 P 0 0.Q In the short run, a monopolist: (A) will never shut down. (B) will shut down if price equals average total cost. (C) will shut down if price is less than average total cost. (D) will shut down if price is less than average variable cost. 95 解 :(D); 獨占廠商短期間停止生產的條件 :TR<TVC 或 P<AVC.A single-price monopoly will set its price according to which of the following rules? (A) P=MR and MR equals MC. (B) P equals MC where the MC curve crosses the demand curve. (C) P equals MR where the MR curve crosses the demand curve. (D) None of the above answers is correct. 95 解 :(D); 對 single-price monopoly 而言, 其最適決策為 MR=MC 且 P>MR.For a single price monopolist, (A) MR=P. (B) MR=<P (C) MR first increases and then decreases with the quantity sold. (D) MR first decreases and then increases with the quantity sold. 解 :(B); 獨占廠商之最適決策 :MR = MC 且 P > MR 95.The profit-maximizing monopolist, faced with a negative-sloping demand curve, will always produce: (A) at an output greater than the output where average costs are minimized (B) at an output short of that output where average costs are minimized (C) at an output equal to industry output under pure competition (D) (A) and (C) (E) none of the above. 95 解 :(E); 獨占廠商之最適產量決定於 MR = MC, 此產量可能大於或小於平均成本為最低的產量水準 4.Mau Inc. has a monopoly in the nut industry. The demand curve and marginal cost curve for nuts are given as follows: P = 60- Q and MC = 4Q. At the profit maximizing level of output, what is the deadweight loss? (A) No deadweight loss at all. (B) around 450 (C) around 900. (D) greater than 800. (E) no way to tell the impact of dead weight loss. 95 解 :(C); 完全競爭解 :P=MC 60-Q=4Q =5.4 獨占解 :MR=MC 60-6Q=4Q =6 獨占的無謂損失 : deadweight loss= P MCdQ 60 7QdQ = 60Q Q Compared to a competitive industry, a monopoly transfers (A) deadweight loss away from producers to consumers. (B) deadweight loss away from consumers to producers. (C) producer surplus to consumers. (D) consumer surplus to producers. 95 Q m 解 :(D); 與完全競爭均衡相比較, 獨占均衡將使產量減少, 價格提高, 如此將使消費者剩餘減少, 且賺取 超額利潤而使生產者剩餘增加, 因此獨占者會利用獨占力, 將消費者剩餘移轉為生產者剩餘 6.One potential advantage that a monopoly might have over perfect competitions is (A)Almost always a lower price. (B)almost always a higher output. (C)diseconomies of scale. (D)possibly an increases incentive to innovate. 96 中央企研所 解 :(D); 獨佔廠商由於長期下存在超額利潤, 因此具有創新誘因, 亦即具有動態上的潛在利益 7. 獨佔廠商不需要擔心生產效率或是成本節省的問題, 因為均可以將成本轉嫁給消費者 解 : ; 獨佔廠商不需要擔心生產效率的問題, 是因為其具有獨佔的力量, 而非具有將生產成本進行轉嫁的 力量 獨佔廠商利用其獨佔力來進行 MR=MC 之利潤極大化決策, 此時不管生產成本為何, 或是否具有生 產效率, 皆能使其利潤達到最大 95 暨南國企所 Q c 5.4 6

7 8.某財貨之價格為 p 需求量為 x 產業之總需求曲線為 p = x 假設第 i 個企業的生產量為 xi 且所有的企業其成本函數均相同: X 8 又假設此產業由一家企業完全獨佔時 利潤最大化的產量為 A 而此產業可讓企業完全自由加入的競爭情況下 均衡時的總產量為 B 請問 B 為 A 的多少倍? (A) 6. (B) 7. (C) 8. (D) 9. 解 (D).獨占均衡 MR 00 x MC 4 x MR MC 00 x 4 x x 0 A 0 8.完全競爭均衡 Step min LAC xi xi LAC 8 F.O.C 0 0 xi min LAC 8 xi xi Step 長期均衡條件 p LMC min LAC 8 代入需求函數可得 x B A 0 x 84 B In general, a perfectly competitive industry with the same costs of production as a monopoly will sell: (A) more output at lower prices than a monopoly. (B) less output at lower prices than a monopoly. (C) more output at higher prices than a monopoly. (D) less output at higher prices than a monopoly. 95 解 (A) 在面對相同的市場需求與成本結構下 Qc Qm 且 Pc Pm 40.Free markets tend to have which of the following social advantage? They (A) maximize profit.(b) maximize the number of goods produced. (C) allocate production to the least-cost producers. (D) minimize consumer surplus and producer surplus. (E) maximize equity. 96 台大國企所 解 (B) 在所有市場型態中 完全競爭市場的產量達到最大且保證達到社會福利最大之境界 故自由競爭 市場的最大社會利益就是保證產量達到最大且使社會福利達到最大 4.Under a price cap regulation, the regulated industry has an incentive to (A) inflate costs. (B) operate efficiently and not inflate its costs. (C) decrease its output. (D) none of the above answers is correct. 95 解 (D) 在完全競爭市場中 價格高限將使產業產量減少 在獨佔市場中 價格高線則會使廠商產量增加 4.In general, a perfectly competitive industry with the same costs of production as a monopoly will sell A more output at lower prices than a monopoly. B less output at lower prices than a monopoly. C more output at higher prices than a monopoly. D less output at higher prices than a monopoly. 94 彰師企研所 解 (A) 在面對相同市場需求線 且成本結構相同下 獨佔均衡下價格比競爭均衡高 4.At the profit maximizing level of output for a monopolist A P=MR and AC=MC. B P=AR and AR=AC. C P=MC and MR>MC. D P>MC and MR=MC. 94 彰師企研所 解 (D) 獨佔廠商利潤極大化決策 MR=MC 時 保證 P MC 44.Compared to the efficient competitive result, the monopolist will: (A) sell the same quantity but at a higher per-unit price (B) restrict quantity to raise the price per unit of output (C) increase total consumer surplus, even though consumers pay a higher price per unit of output (D) pay a higher

8 price per unit of labor employed. 96 政大經研所 解 (B) 獨占與完全競爭的比較 完全競爭 獨占 均衡價格 較低 較高 均衡數量 較多 較少.具有生產效率 在 LAC.缺乏生產效率 不一定在 LAC 最低點之處進行生產與銷 最低點之處進行生產與銷售 效率觀點 售.缺乏配置效率 P LMC.具有配置效率 P LMC 社會福利 不存在無謂損失 有無謂損失 長期利潤 0 0 $ MC P(獨) P(完) Q(獨) MR Q(完) P=AR Q 45. A monopolist operates plants. At plan A, MC Q A, and at plant B. If the demand for the monopolist s output is P = 800 Q, then how much is produced at each plant? (A) 50 units at each plant. (B) 00 units at each plant. (C) 00 units at plant A and 00 units at plant B. (D) 00 units at plant A and 00 units at plant A. 95 逢甲財金 企研所 解 (D) 多工廠最適決策 MR MCi QA* 00 MR MC A ;800 QA QB QA * MR MC ;800 Q Q Q B A B B QB 有一廠商設有甲 乙兩工廠 生產同一產品 甲工廠之邊際成本為 MC = Q 乙工廠之邊際成本為 MC = 50 Q, 若此一廠商要生產 70 單位 則甲 乙兩個工廠應各生產多少單位? (A) 甲生產 0 單位 乙生產 40 單位 (B) 甲生產 5 單位 乙生產 5 單位 (C) 甲生產 40 單位 乙生產 0 單位 (D) 甲生產 45 單位 乙生產 5 單位 95 解 (C) MC MC Q 50 Q Q Q 70 聯立求解可得 Q*=40 Q*=0 48.If the regulatory agency sets a price where AR = AC for a natural monopoly then her output will be (A) equal to what produced in competitive level. (B) equal to the monopoly profit maximizing level. (C) greater than the monopoly profit maximizing level yet less than the competitive level. (D) greater than the competitive level. (E) the monopoly will leave this market for sure. 95 解 (C)

9 $ P m LAC LMC Qm MR Q QC AR Q 如上圖所示, 對自然獨占廠商而言, 平均成本管制下的產量 ( Q ), 將會小於完全競爭產量 ( Q ), 但大 Q m 於獨占均衡下的產量 ( ) c 49. 關於自然獨占產業, 以下何者為錯誤的敘述? (A) 平均固定成本隨產量增加而遞減 (B) 平均成本隨產量增加而遞減 (C) 邊際成本隨產量增加而遞減 (D) 基於社會福利極大所定之價格將導致廠商虧損 (E) 以上敘述皆對 95 解 :(C); 自然獨占廠商具有規模經濟之特性 50. Imposing price cap regulation on an unregulated natural monopoly will result in a ;In the price and in the quantity. (A) fall, a decrease (B) fall, an increase (C) rise, an increase (D) rise, a decrease 95 解 :(B); 對自然獨占廠商進行價格高限, 會使其價格降低, 產量增加 5.According to social interest theory, when a monopoly exists politicians will introduce regulations that will. (A)decrease prices and keep the level of output constant (B)increase output and decrease prices to their competitive levels (C)increase prices and increase the level of output (D)decrease prices and decrease the level of output 96 嘉大管研所 解 :(B); 政府基於社會福利最大之目標, 對獨占者採取邊際成本管制法下, 將使獨占者的價格下跌且產量 增加 5.() 成本遞減產業所形成的獨占稱為 () 公共財有哪兩個特徵? () IS 曲線是由商品市場的均衡條件而得, 政府支出增大時向 ( 請選擇右或左填入 ) 移動, 儲蓄意願增加時向 ( 請選擇右或左填入 ) 移動 (4) LM 曲線是由貨幣市場的均衡條件而得, 實質貨幣供給量減少時則 ( 請選擇右或左填入 ) 移動, 貨幣的資產需求增大時則向 ( 請選擇右或左填入 ) 移動 (5) 貨幣需求的利率彈性為 0 時,LM 曲線為 ( 請選擇垂直 水平 左下 右上之斜線 左上右下之斜線填入, 單選 ), 貨幣需求的利率彈性為負無限大時,LM 曲線為 ( 請選擇垂直 水平 左下 右上之斜線 左上右下之斜線填入, 單選 ) 95 高雄第一科大行銷所 解 :. 自然獨占. 不具有敵對性與不具有排他性. 右移, 左移 4. 左移, 左移 5. 垂直線, 水平線 5.If a firm faces a rate of return regulation, and if the regulator can observe the firm s total cost and knows that the firm has minimized total cost, the firm will produce output at the point where. (A) the marginal cost and demand curves intersect. (B) the average total cost and demand curves intersect. (C) the average total cost and marginal cost curves intersect. (D) the marginal revenue and marginal cost curves intersect. 95

10 解 :(B); 合理報酬率管制法是平均成本管制法的一種 54. 自然獨占的廠商, 具備何種生產結構? (A) 外部性 (B) 利潤極大 (C) 規模報酬 (D) 規模經濟 解 :(D); 規模經濟形成自然獨占的必要條件 政府要求一自然獨占廠商生產合乎經濟效率之產量, 則可能須要求它 : (A) 差別取價, 以便繼續留在產業 (B) 接受政府補助, 以便繼續留在產業 (C) 負擔虧損 (D) 在長期邊際成本與需求曲線相交處生產 (E) 以上皆是 95 解 :(E); 當政府對自然獨占廠商進行邊際成本管制時, 廠商必生產在 P = MC 之處, 此時廠商面臨虧損, 若要廠商能繼續經營, 政府必須給予補貼或允許廠商採取二段式訂價或多段式訂價等差別取價方式來解決虧損 56.When regulators use a marginal cost pricing strategy to regulate a natural monopoly, the regulated monopoly (A) has no incentive to exit the industry (B) will experience a price below average total cost (C) may rely on a government subsidy to remain in business (D) both (B) and (C) 解 :(D); 政府對自然獨佔廠商採取 P=MC 管制法, 將使廠商發生損失 ; 若政府不予補貼, 廠商將退出市 場 96 銘傳財金所 57.Which of the following is the unique characteristic of natural monopolies that other monopolies do not share? (A) Economies of scale over the entire range of market output. (B) The marginal cost curve is always above the average total cost curve. (C) It is to a natural monopolist s advantage to produce the output where MC equals price. (D) All monopolies are natural monopolies. 交大科管所 解 :(A) 自然獨占廠商最大特色 - 規模經濟, 隨著產量增加, 長期平均成本遞減, 規模經濟是自然獨占與 其他獨占廠商最大差異 58.Which of the following is the best indication of high market power? (A) A small firm with a market share of 80 percent. (B) A firm with $0 billion in sales in a market with an HHI of 800. (C) A large firm with a concentration ratio of 0 percent. (D) An elastic demand curve for the firm s product. 交 大科管所 解 :(A);( B) 當 HHI<000, 表示產業競爭情況良好, 當 HHI>800 時, 則表示市場集中度極高 (D) 當市場需求彈性愈大時, 表示獨占力越低 59.Consider three ways of allocating two goods in a two-person exchange economy. I. Both individuals take prices as given and equilibrium prices are established by an impartial auctioneer. II. One individual can act as a perfect price discriminator and force the other individual to pay a different price for each unit of a good that is traded. III. One individual is a monopolist and can charge the other individual a single, utility-maximizing price. Which of these situations is efficient? (A) None of them. (B) Only I. (C) I and II, but not III (D) I and III, but not II. (E) All of them. 95 政大企研所 解 :(C);I: 透過喊價 ( 市場機能 ) 運作的完全競爭均衡必具有效率 II: 完全價格歧視均衡必具有效率 III: 進行單一定價獨占均衡將不具有效率 60.Suppose the demand for a movie ticket can be written P = 0 Q for senior citizens and P = Q for all other consumers. If the movie theater coffer tickets to a movie at zero marginal cost and can verify the purchaser s age, what price will be charged? (A) Seniors pay $5, everyone else pays $6 (B)

11 Everyone pays $5.5 (C) Seniors pay $6, everyone else pays $5 (D) Seniors get in for free, everyone else pays $. 95 逢甲財金 企研所 解 :(A); 差別取價均衡條件 : MRi MC * * MR MC;0 Q 0 Q 5, P * * MR MC; Q 0 Q 6, P 關於獨占廠商的差別定價行為, 以下何者為正確的敘述? (A) 市場需求彈性越小, 定價越低 (B) 定價與 市場需求彈性的關係無法確定 (C) 限制廠商不得差別定價必定提高消費者剩餘 (D) 限制廠商不得差別定價 必定提高社會福利 (E) 以上皆非 95 交大經管所 解 :(E); 在第三級差別取價下, 廠商將依反彈性定價原則來定價 (B), 市場需求彈性越小, 則定價越高 (A), 限制廠商不得差別取價, 只能統一定價 (single-price policy) 下, 消費者剩餘可能會增加, 但亦可能會減 少 (C), 導致社會福利水準亦可能增加或減少 (D) 6.Johnny operates a used car dealership. He spends $5,000 per month to rent the lot and office space. He obtains used cars for $,000 each. The demand for used cars can be written as P = 6,000,000Q,where P is measured as $ per used car and Q is measured as used cars per month. If Johnny can perfectly price discriminate, his monthly profit will equal (A) $0 (B) $7,500 (C) $0,000 (D) $5, 逢甲財金 企研所 解 :(B); max Q dq 000Q 5000 f. o. c. 0 Q 5, If a price discriminating monopoly charges a lower price to students, it is likely that the firm(a) believes that student demand is relatively elastic. (B) believes that student demand is relatively inelastic. (C) wants to shift student demand. (D) is primarily concerned about the well-being of students. 95 * * 解 :(A); 當廠商進行第三級差別取價時, 彈性越大, 訂價將越低 Q 65.() 北美鐡路運輪公司經營 A 城市與 B 城市間之每日鐡路貨運, 北美鐡路運輸公司的二個主要客戶為美洲鋼鐡公司及中西農產公司, 止二公司對鐡路貨運車箱之需求如下列方程式所示 : P=500-8Q, 美洲鋼鐡公司 : P=400-5Q, 中西農產公司, Q 是每趟貨運所拖掛車箱, 若北美鐡路運輸公司欲採差別取價, 須具哪些條件 : (A) 北美鐡路運輸公司可區隔市場 (B) 產品在區隔之市場無法轉售 (C) 在區隔之市場需求彈性不同 (D)(A)&(B) (E)(B)&(C) (F)(A)&(C) (G)(A) (B)&(C) () 如上題所示, 北美公司最適價格 數量各為何? (A) P = $66,P = $6;Q= 0,Q = 8 (B) P = $0,P = $80;Q = 8,Q = (C) P = $60,P = $0;Q = 0,Q = 8 (D) P = $0, P = $60;Q = 8,Q = 5 (E) 以上皆非 () 如上所示, 北美公司最大利潤,MR MR 各為何? (A) 最大利潤 =440,MR=40,MR=0 (B) 最大利潤 =440,MR=40,MR=40 (C) 最大利潤 =4440,MR=0,MR=0 (D) 最大利潤 =440, MR=0,MR=0 (E) 以上皆非 95 台大經研所 解 :()(G) () (C); 本題在沒有給定成本函數下, 必需利用選向來猜測合理解, 依據反彈性定價原則 : 00 0Q MR MC MR 500 6Q 400 0Q Q 6 當 Q 8 時, Q 0 P P

12 () (E) MR MR MR MR MC A firm is charging a different price to each customer. This is called : (A) first-degree price discrimination. (B) second-degree price discrimination. (C)third-degree price discrimination. (D) fourth-degree price discrimination. 96 中正企研所 解 (C) 廠商對不同消費者訂定不同價格 稱為第三級差別取價 67. A firm is a monopolist in its domestic market where imports are banded, and it can choose whether to export to a perfectly competitive international market. Suppose that the firm s marginal cost is MC(Q)= Q, where Q is its total output volume, the domestic market demand is Pd = 00 - Qd, where Pd and Qd are the price and the quantity in the domestic market, respectively, and the price in the international market is Pe = 0. () How many units of output will this firm produce, in order to maximize its total profit? () What is the optimal domestic price for the firm? () If the international price drops to 7, other things remaining the same, how many units will be exported by this firm to the international market? 95 元智國企所 00 Q d Q d 0Qe 解. Max d Q Qe 6 F.O.C 0 Q d 00 4Q d 0 Qe d Q Qe 0 d Q Qe 00 Q d Q 0 e 聯立求解可得 Qd 0 Qe 40 0 d Q Qe 0 Q Qd Qe 60. Pd 00 Qd 60. Max 00 Q d Q d 7Qe d Q Qe Q d Q d Qe 0 d Q 9 Qe Q d Qe 0 聯立求解一階條件可得 Qd 4 Qe F.O.C 由於 Qe 0 表示在國際價格降為 Pe 7 時 廠商的最適決策為 Qe 0 不再出口 68. Rather than charging a single price to all customers, a firm charges a higher price to men and a lower price to women. By engaging in this practice, the firm: (A) is trying to reduce its cost and therefore increase its profit. (B) is trying to reduce its reported costs but not its real costs. (C) is attempting to convert producer surplus into consumer surplus. (D) is attempting to convert consumer surplus into producer surplus. (E) both (A) and (C) are correct. 95 解 (D) 廠商差別取價的目的往往是為了剝奪更多的消費者剩餘 來獲取更高的利潤或生產者剩餘 69.某獨占市場的需求函數為 Q=00-P 單位生產成本固定為 0 當廠商採取一級或完全差別定價時 最 大的利潤是

13 解 : ; Max ( 00 Q) dq 0Q F.O.C: 00 Q = 0 Q* = 80 Q * 00Q Which of the following is NOT necessary for a monopoly to increase its economic profit by discriminating among groups of buyers? (A) The firm must be able to separate different buyer types. (B) The firm must be able to identify each individual consumer s precise willingness to pay.(c) Each group of buyers must have a different average willingness to pay. (D) Resale of the product is difficult or unlikely. 95 解 :(C); 消費者具有不同的需求價格並不是廠商執行差別取價的必要條件 7. Which of the following statements is true? (A) Perfectly competitive markets are efficient, but monopoly markets never are. (B) Perfectly competitive markets always reach equilibrium but monopoly markets never reach equilibrium. (C) Perfect price discriminating monopolists can eliminate all deadweight losses and achieve efficiency. (D) All the above statements are true. 95 解 :(C); 完全價格歧視下廠商將生產在 P=MC, 具經濟效率 7.Which of the following is NOT necessary for a monopoly to increase its economic profit by discriminating among groups of buyers? (A) The firm must be able to separate different buyer types. (B) The firm must be able to identify each individual consumer s precise willingness to pay.(c) Each group of buyers must have a different average willingness to pay. (D) Resale of the products is difficult or unlikely 解 :(C); (A)(B)(C) 皆是獨占廠商進行差別取價的基本條件 7.Which of the following statements is true? (A) Perfectly competitive markets are efficient, but monopoly markers never are. (B) Perfectly competitive markets always reach equilibrium but monopoly markets never reach efficiency. (C) Perfect price discriminating monopolists can eliminate all deadweight losses and achieve efficiency. (D) All the above statements are true. 95 解 :(C); 完全歧視廠商的最適決策滿足 P = MC, 以致於達到社會福利最大境界 74.[ 解釋名詞 ] Perfect price discrimination 95 解 : 完全價格歧視, 或稱為第一級差別取價 ; 廠商依據消費者的需求價格來訂定每單位商品的售價, 此時消費者實際支出的總額會等於其所願意支出的總額, 而使消費者剩餘完全被剝削 當廠商進行完全價格其事時將按 P=MR=MC 來進行決策, 因此其產量不但具有資源配置效率, 且保證社會福利最大 75. 在下圖中顯示 勁力公司 台灣市場和日本市場電池之需求曲線, 下列各定價方案中, 何者會帶來較高 的利潤? 95 交大經管所

14 $ $ AR 40 MR Q Q AR MC=40 MR Q Q Q Q (A) 日本市場定價 $60 台灣市場定價 $00 (B) 日本市場定價 $60 台灣市場定價 $40 (C) 日本市場定價 $00 台灣市場定價 $60 (D) 日本市場定價 $00 台灣市場定價 $40 解 (A) 依據第三級差別取價原則 MR=MC P = 60 MR=MC P = When the movie Jurassic Park debuted in Westwood, California, the price of tickets was $7.50. After several months the ticket price had fallen to $4.00 This is an example of (A) peak-load pricing.(b) second-degree price discrimination. (C) a two-part tariff.(d) tying. (E) none of above. 解 (E) 屬於 inter-temporal price discrimination 96 銘傳國企所 財金所 77.Product differentiation allows the firms to (A)raise price and lower quantity demanded. (B) raise price without suffering a substantial loss of sales. (C) shifts the market demand curve to the left. (D) decrease barriers to entry. 交大科管所 解 (B) 產品差異化可以使產品需求彈性變小 提高廠商獨占力 此時廠商可以提高價格增加總收益 78.美國許多圖書公司在出版學術書籍時 經常會先出版訂價較高的精裝本 二年後再出版訂價較低的平裝 本 請說明其理由何在 96 政大經研所 解 此即 跨期差別取價(intertemporal price discrimination) 的應用 書商將相同商品在不同時 點 訂定不同價格 說明如下 () 一旦書籍編寫完成 剩下的便只有重製的成本 而無論何時 再製的成本幾乎相同 已排版 編 輯完成 只需印刷成本 故假設 MC AC a () 假設有一群讀者十分想一睹新書 對於學術新知有強烈的求知慾望 需求線為 D 需求彈性較小 根據利潤極大化的一階條件 MR MC a 廠商訂價為 P () 假設另外有一群較不熱衷於新知的消費者不急著一睹新書內容 需求線為 D 同理可知 MR MC a 訂價為 P (4)由上知 廠商是針對不同的消費者 依其不同的需求彈性而訂定不同售價 且為反彈性訂價 即彈性 低的訂高價 彈性高的訂低價 79.Many airlines promise frequent flyer miles to passengers who fly their airlines regularly. This is an example of a firm attempting to create (A) price discrimination. (B) a predatory pricing scheme. (C) discounting below marginal costs. (D) brand loyalty. 交大科管所 解 (A) 航空公司鬼與定期飛航旅客里程優惠服務是一種差別取價策略 80.Charging lower rates to large users for successive blocks of output is an example of: (A) first-degree price discrimination (B) second- degree price discrimination (C) third- degree price discrimination (D) inverted blocks pricing (E) none of the above. 95

15 解 (B) 8.A local restaurant offers an all you-can-eat salad bar for $.49. However, with any sandwich, a customer can add the all-you-can-eat salad bar for $.49. This is an example of (A) peak-load pricing. (B) second-degree price discrimination. (C) a two-part tariff. (D) tying. (E) none of above. 96 銘傳國企所 財金所 解 (C).49 視為門票 每一個三明治收取.49 視為使用價格 因此是 two part tariff 8.某獨佔廠商有兩類的消費者 一類是 H 型 PH 0 QH 另一類是 L 型 PL 5 QL 獨佔廠商 成本函數為 C 5(QH QL ) 廠商無法區別任一消費者所屬的類型 因此廠商想要設計兩套不同的銷售方 案 讓消費者自選 根據這套最佳的二級差價銷售方案 廠商的利潤是多少 (A) 50 (B) 5 (C) 6.5 (D) 以上皆非 96 淡江經研所 解 (D) P 0 CSL 5 P* P* 5 0 MC=5 Q 低消費的消費者剩餘函數為 CSL (5 P) 廠商追求利潤極大下 Max CS L ( P MC) (QL QH ) (5 P) ( p 5) (5 P) F.O.C (5 P) ( ) (5 P) ( P 5) 0 P P 0 5 P P P P* 7.5 CS L* 8.5 * (5 P * ) ( P * 5) (5 P * ) (7.5) (.5) (0) A monopolist sells on a market consisting of two types of consumers. The first type of consumers have aggregate demand function Q (p) 6 P and the second type of consumers have aggregate demand function Q (p) 0 P. The monopolist's marginal cost is constant and equal to. ()The monopolist does not know there are two different types of consumers. However, he knows the market demand function. Compute the monopoly price, quantity, and the monopolist's profit. ()Suppose the monopoly now knows there are two types of consumers and knows their demand curves. The monopolist will treat the two types of consumers as two separate markets and charge different prices. Find the two prices the monopolist charges each group of consumers, as well as quantities sold to each group and the profits the monopolist earns from each group. 96 暨南財金所 解 () The monopolist does not know there are two different types of consumers: Step. 求出市場總需求線與 MR 線 Q 6 P P 8 Q 0 P P 5

16 P 5, QAll 0 8 P 5, QAll Q 0 P P 8, QAll Q Q 46 4P P 5, Q All 0 8 P 5, P 5 Q All P 8, P Q All 4 MR 5 QAll, when 8 P 5 MR QAll, when P 8 Step. 求解廠商追求利潤極大化均衡價格及數量 廠商追求利潤極大化的一階條件為 MR MC * MC 5 Q All Q () The monopolist knows there are two types of consumers:( 差別取價 ) Q 6 P P AR 8 Q MR 8Q MC Q * * 6 P 8 (6) 5 Q 0 P P AR 5 Q MR 5Q MC Q * * P 5 () Microsoft, a software service company, sells two software programs that all its customers regard as separate products, PowerPoint and Word. The reservation prices for the various groups of potential customers are as follows, Category of customers All or or Reservation price for Microsoft PowerPoint Reservation price for Microsoft Word Students $800 $000 Professionals under age 50 $500 $600 Professionals over age 50 $000 $000 The marginal cost of each software copy is $ (for PowerPoint or for Word). There are equal numbers of potential consumers in each category. (A)If Microsoft practices simple monopoly pricing for the two software programs, a professional under age 50 will only buy PowerPoint.(B)If Microsoft practices simple monopoly pricing for the two software programs, a professional over age 50 will only buy Word.(C)If Microsoft uses a mixed Q Q All All 5 MC * Q * All QAll 9 * 7 * P 5 () 4 ** 7 * P (9) ** * * 7 均衡時 P * ** ** 6 P Q Q 9 4 4

17 bundling price policy, a student will buy the bundle.(d)if Microsoft uses a mixed bundling price policy, a professional over age 50 will buy the bundle. 解 :(D) 令 Power Point 價格為 P,Word 價格為 () 分開訂價 : 96 台大經研所 因此, 在最適分開訂價下,Power Point 只有超過 50 歲的專業人士將會購買 ;Word 只有學生不 會購買 () 純粹成批訂價 : 利潤最大的最適訂價為 : P, 000 因此, 在最適純粹成批訂價下, 二種軟體只有學生不會購買 () 混合成批訂價 : 利潤最大的最適訂價為 : 成批訂價 : P, 000, 分開訂價 : P,500, 因此, 在最適混合成批訂價下, 超過 50 歲的專業人士將會成批購買而不會分開購買 (A) 錯 (B) 錯 (C) 錯 (D) 對 85.Explain and show why a monopolistic firm produces an output at which demand is inelastic in the long run. 解 : d E F.O.C: 0 MR MC 0 MR MC Q (Lerner Index) I 愈小 市場需求曲線愈陡值, 產的產能會位於缺乏彈性之處 P P 96 高雄大學經研所 MC 0 MR 斜率小於 MC 斜率 Q* P W 利潤最大的最適訂價為 : P,500, P,000 W Max TRTC d S.O.C: MR Q dq MR(Q) P( PW PW P E L d d dq ) MC(Q) P P[ P MC P MR d E P P P I L ] d E P,000 W 愈大, 代表獨占力愈高, 因此長期追逐利潤極大化的獨佔廠商生 86. 以下何者為差別取價 : (A) 午夜之後的電影票價較低 (B) 來回機票, 若回程不安排在週六夜間, 票價較低 (C) 超級市場給所有顧客折價卷 (D) 製藥廠給醫院的價格較藥店的價格低 (E) 加油站對付現及使用信用卡之顧客收一樣之價錢 (F) 以上皆非 95 解 :(C); (A)(B) 為尖峰訂價法 (C) 折價券的收集與使用需要耗費時間, 因此可花時間者方可享受折價優惠, 而時間成本低者通常需求彈性較大, 故對使用折價券者給予優惠屬於第三級差別取價 (D)(E) 是基於成本的不同而產生訂價的差異 87. 張三擁有某一地區唯一之礦泉水之水源, 張三希望由此一成本為零之產品獲取最大利潤, 張三會要求他的顧客攜帶自己的取水容器, 並且 :(A) 訂最高之可能價格, 出售價格下之能數量 (B) 訂最低之可能價格, 出售儘量多的數量 (C) 訂 MR=0 之價格 (D) 顧客願付多少就付多少錢 (E) 訂 MR 最高之價格 95 解 :(C); 獨占廠商利潤最大化之條件 :MR = MC = 0 ( 註 : 如果獨占者按所有顧客願意付出的價格來訂

18 價, 此為完全價格歧視, 此時可獲得更高利潤 但若由顧客自己想付多就付多少, 則會產生 free rider, 反 而收不到錢 ) 88.The purpose of advertising for Coca-Cola is to (A) increase the cross elasticity of demand between Coke and Pepsi and thus increase the elasticity of demand for Coke. (B) increase the cross elasticity of demand between Coke and Pepsi and thus decrease the elasticity of demand for Coke.(C) decrease the cross elasticity of demand between Coke and Pepsi and thus increase the elasticity of demand for Coke. (D) decrease the cross elasticity of demand between Coke and Pepsi and thus decrease the elasticity of demand for Coke. 95 成大企研所 解 :(D); 可口可樂廣告的目的是希望能透過廣告來表現其產品特質而降低與百事可樂的替代彈性 當 Coke 與 Pepsi 的替代程度降低時, 即能降低消費者對 Coke 的需求彈性 ( 註 : 當商品的需求彈性變小時, 廠商 的獨占力將提高 ) 89.Firms use advertising to create brand loyalty. In markets where brand loyalty is created, the firm can (A)price below marginal cost. (B)price above marginal cost. (C)price equal to marginal cost. (D)maximize profits where marginal revenue is lower than marginal cost. 96 中央企研所 解 :(B); 廣告可提高消費者品牌忠誠度, 使獨佔力提高, 使 P>MC 90.One of the reasons that concentration raitos are not a perfect measure of competitiveness is that(a) they ignore potential competition. (B) they cannot be measured. (C) they tell nothing about how high prices were in the past. (D) they do not measure how high the industry s prices are. 95 解 :(A); 集中度指標只能反應市場中大戶的實力, 卻無法顯示市場中潛在競爭者的情況 9. 如果長期處於獨佔性競爭下 (monopolistic competition), 則公司的廣告費用將無法獲得正的經濟利潤 (positive economic profit) 95 解 : 是 ; 當廠商利用廣告來進行異質性的競爭時, 短期間縱有超額利潤, 長期間透過自由進行的競爭, 將使經濟利潤等於零 9. 獨佔廠商不需要擔心生產效率或是成本節省等問題, 因為均可以將成本轉嫁給消費者 解 : 否 ; 獨占廠商不需要擔心生產效率的問題, 是因為其具有獨占的力量, 而非具有將生產成本進行轉嫁 的力量 獨占廠商利用其獨占力來進行 MR=MC 之利潤極大化之決策, 此時不管生產成本為何, 或是否具 有生產效率, 皆能使其利潤達到最大 95 9.The degree of operation leverage is equal to the change in divided by the change in (A) percentage; sales; percentage; EBIT (B) unit; sales; unit; EBIT (C) percentage; EBIT; percentage; sales (D) unit; EBIT; unit; sales (E) none of the above. 95 解 :(C); 營業槓桿的程度 (DOL) 指的是 銷售額變動的百分比 對 EBIT( 稅前 / 息前盈餘 ) 百分比 的影響 94.What of following statement(s) about monopoly market is (are) correct? (A)The profit-maximizing monopolist will never produce an output in the inelastic range of its demand curve. (B)Since the monopolist has the strongest market power, its profit must be positive even in the short-run. (C)Advertising is the principal method that a monopoly firm uses to increase the demand for its products. (D)(B), (C) are correct. (E)All of the above is incorrect. 96 逢甲財金 企研所 解 :(A); 95.Suppose you own a business and your own price elasticity is In addition, suppose your advertising elasticity of demand is 0.0. If your marginal cost per unit is $4 what is your optimal

19 advertising-to-sales ratio? (A) 0.75 (B) 0.65 (C).670 (D) 中山財管所 解 (A) 依據 Dorfman-Steiner model 可知 A E 0. Ad 0.75 P Q E The table above gives the market share of sales of firms in the retail clothing market. What is the four-firm concentration ratio? Firm Market share (percentage of sales) Susan's Stitches 40 Tommy's Threads 5 Robert's Wardrobe 0 Katie's Klothes 0 Greg's Garments 0 Amy's Attire 5 (A)70 percent (B)65 percent (C)85 percent (D)00 percent 96 嘉大管研所 解 (C) 97.政府如果對邊際成本固定的廠商課 0 元的單位稅 這 0 元的單位稅會全部轉嫁給消費者 解 對市場需求線為直線且 MC 為固定的獨占廠商課徵 0 元的從量稅 將使價格上漲 5 元( P ) t 如果一個追求利潤極大的獨占廠商其邊際成本線上移了 0 元 則價格會 (A)上升 且增幅恰為 0 元 (B) 上升 且增幅小於 0 元 (C)上升 且增幅大於 0 元 (D)不變 但利潤減少 95 解 (B) 在市場需求為直線(P = a bq)且 MC 為水平線 MC = C 下 dp p' dc MR' 故當 MC 上升 0 元下 將使價格上漲小於 0 元 99.如市場獨占者進行逃漏稅行為時 利潤稅仍具有 中立性(neutrality) 嗎 96 高雄大學經研所 解 ()未課徵利潤稅下 Max TR TC F.O.C 0 MR MC Q S.O.C MR 0 MR MC Q 廠商依 MR MC 決定最適產出 Q * 再代回需求線決定市場價格

20 $ MC P* AR Q Q* MR () 政府課徵利潤稅 廠商不逃稅 max t ( t ) ( t ) (TR TC) F.O.C t 0 ( t ) (MR MC) 0 Q S.O.C t ( t ) (MR MC ) 0 MR MC Q MR MC 廠商最適決策與未課稅時相同 亦即課稅行為並未影響市場均衡價量 此一情況稱為利潤稅具 有中立性 () 政府課徵利潤稅 廠商逃稅 Max TR TC 廠商決策過程無須考慮租稅 決策方式及市場均衡價量與未課稅時相同 因此利潤稅仍具中立 性 (4)結論 政府課徵利潤稅之下 無論廠商是否逃稅 皆不影響市場均衡價量 亦即利潤稅具有中立性 廠商逃稅與否的差異僅在於選擇逃稅的廠商所獲取的利潤( )較誠實納稅廠商的利潤( ( t ) )高 0.The demand for a monopolist s output is 7000 /( P ) where P is the price she charges. At a price of 0, the elasticity of demand for the monopolist s output is: (a) (b).54 (c).54 (d).04 成大財金所 解 (c) 7000 (P ) Qd 全微分 dq 當 P 0 Q (P )dp 4000dP (P ) 4 (P ) dq 4000 dp (P ) d dq P dp Q (0 ) 69-0.The marginal cost of a monopolist is constant and is $0. The marginal revenue curve is given as follows: MR 00 Q.The profit maximizing price is (a)$70(b)$65(c)$60(d)$55(e)$50 政大經研所 解 (d) MR MC 00 Q 0-7 Q* 45, P* 00 Q 55

21 0.The demand for a monopolist s output is /( P ) where P is her price. (a)she will always equate marginal revenue and marginal cost when maximizing profit. (b)since she will charge a price according to the MR MC rule, she will produce an efficient amount of output. (c)if the price is set at $8, the elasticity of demand for the monopolist s output is 6 / 5. (d)if she has constant marginal costs equal to $6 per unit, she will charge $4 per unit to maximize her profits. (e)none of the above. 台大財金所 解 (a)(c)(d) (a)獨占廠商利潤極大的均衡條件 MR MC (b)社會福利極大的定價為 P MC 當 P 8 Q 900 (P ) (P ) 全微分 dq d dp (P ) 4 dq 4 dp (P ) 6 dq P 4 8 d. 5 dp Q (c) Q d 04.A monopolist will never produce at a point where demand is price inelastic. 東吳經研所 解 不一定 當一個獨占廠商面對一條直線且具有負斜率的直線時 大部份會在 d 之處生產 但有以下例外 P MC d ()if MC 0 時 P d 0 d 當廠商 MC 0 時 會在 d 之處生產 ()if MC 0 MR 0 P 0 d d 當廠商 MC 0 時 會在 d 之處生產 在需求曲線中點之處生產 此時廠商獲取最大收益 ( TR ) P d d MR d P AR Q ()廠商採完全差別取價時 有可能會在需求曲線上任一點生產 廠商訂價會完全剝奪 CS 此時廠商有可能會在 d 或 d 或 d 之處生產

22 05.在獨占市場中因為廠商具有獨占力量 所以廠商可以利用漲價來提高其銷貨收入 解 錯誤 獨占廠商必會在 d 之處生產 可以利用降價來提高銷貨收入 d 則 -4 政大金融所 dtr Q [ d ], if dp dtr 0 此時 P TR dp 06.A competitive firm has a single factory with the cost function C( y) 4y 89 and produces 8 units in order to maximize profits. Although the price of output does not change, the firm decides to build a second factory with the cost function 8y 9. To maximize its profits, how many units should it produce? (a)4 (b) (c)9 (d) (e)none of the above. 中正財金所 解 (a) 對完全競爭廠商而言 利潤極大的條件 P MC 原先成本函數 C( y) 4y 89 MC 8y P 生產 8 單位 P 對新廠而言 MC 6y 在 P MC定價下 4 6y y 4 07.A firm has two factories. One factory has the cost function c ( y) y 90. The other has the cost function c ( y) 6y 40. If the firm wishes to produce a total of units as cheaply as possible, how many units will be produced in the second factory? (a)7 (b) (c)8 (d)8 (e)none of the above. 中正財金所 解 (c) 均衡時 MC MC 4y y y y 又知總產出 Y y y 4 y y * 8, y* 8 08.下列是幾個差別取價之事例 請選出符合三差別取價原則之例子 (a)學生優惠票 低於一般大眾 制度 (b)高速公路採短程使用者高收費 長程使用者低收費 (c)雜誌圖書館訂閱高價 學生訂閱低廉 輔大金融所 (d)國內市場採高價以津貼國外低價傾銷 解 (c)(d) 第三級差別取價為針對不同的市場 需求彈性高和需求彈性低 收取不同的價格 其需求彈性較高的 市場其價格較低 09.某經濟學學術期刊學校圖書館訂購一年為 00 元美金 老師訂購一年為 0 元美金 學生訂購一年為 5 元 請分析其經濟涵意 政大財管所 解 此為差別取價行為 假設圖書館 老師 學生市場能完全區隔之下 在學生所得有限情況下 對學術 期刊富有彈性 而圖書館為了館藏需要對學術期刊相當缺乏彈性 假設經濟學術期刊廠商追求利潤極大 化 採差別取價訂價法 依反需求彈性訂價原則 if 圖 老 師 學 生 d d d * * * 則 P圖 P老 師 P學 生 0.電器行打出這樣的廣告 只要繳回舊的電視 即使壞掉的也可以 購買新電視即可享有 0%的折扣

23 請問這種促銷手法有何經濟學的理論根據 政大財管所 解 此種促銷方法可視為差別取價 家裡尚有舊電視者 對新電視需求彈性較大 尚有舊電視之替代品 家裡無電視者 對新電視需求彈性較小 無替代品 廠商為了追求利潤極大 採取反需求彈性訂價原則 對家裡有舊電視者 只要繳回電視 即可享受折 扣 訂價較便宜 以此刺激買氣 增加營收.()一廠商生產某項商品的邊際成本為常數$0 假設只有兩個消費者 其中消費者 的需求是 D 00 P 而消費者 的需求是 D 00 P 但因二位消費者外表完全一樣 故廠商無法區分 二人的需求狀況 假設此廠商可進行二部收費 two-part tariff 先收取基本費 A 再收取單位價格 P 則此廠商的利潤極大化訂價方式為 (a) A 780, P 5 (b) A 400, P (c) A 4050, P 0 (d)兩消費者皆會選擇購買 (e)只有一位消費者會購買 ()承續上題 但假設此廠商無法從事任何差別取價或二部收費 僅能收取單位價格 P 則利潤 R 將是多 少 (a) R 870 (b) R 050 (d) R 40 (e)以上皆非 (c) R 60 台大經研所 解 ()(c)(e) 二位消費者均購買 基本費用為消費者剩餘較少之消費者之消費者剩餘值 第二個消費者 P MC 0 D D Q Q 00 Q Max P(Q Q ) A 0(Q Q ) P(00 P 00 P) (50 P) Q 0(00 P 00 P) P(00 P) (50 P) (00 P) 0(00 P) 00P P P 00P P 000 0P P 0P P 0 0 P* 5, * 5, A* 450 P 只有一位消費者購買 消費者剩餘較高者

24 Max P Q A 0 Q P(00 P) (00 P)(00 P) 0(00 P) Max 00P P P P 000 0P P 0P 4000 P 0 0 P* 0, * , A* 4050 P P* 0 A* 4050 只有消費者 會購買 ()(e) 廠商無法從事差別取價或二部收費 因此對二位消費者採取統一訂價 <step > 先將二位消費者需求曲線做水平加總 Q 00 P, if Q 0, P 00 Q 00 P, if Q 0, P P 00 P 00 Q 50 P 00 Q 00 P 00 Q P 50 P P 50 Q 00 P <step > 將市場需求函數轉成廠商 MR 50 P 00 M R 00 Q 00 P 50 M R Q <step > 廠商追求利潤極大化 採 MR MC 訂價 case 50 P Q 0 Q* 45, P * 符合 case P Q 0 Q* 85, P * 符合 <step 4> 比較利潤值大小 if P * 55, Q* 45, * 45(55 0) *, Q* 85, * if P 5 統一訂價 P * 利潤 R * 408.Club Med, which runs a number of vacation resorts, offers vacation packages at a lower price in the winter, the off season than in the summer. This practice is an example of: (a)peak-load pricing. (b)intertemporal price discrimination. (c)two-part tariff. (d)bundling. (e)both (a) and (b) are correct. 中山經研所 解 (e) 在冬季時 廠商提供較優惠渡假組合 在離峰需求時 亦提供較優惠組合 為跨期差別取價及尖峰訂價 法應用 Intertemporal price discrimination 在跨期差別取價之下 消費者可以被分隔成不同群

25 體, 各自擁有不同需求函數, 在不同時段收取不同價格 廠商透過不同時間訂定不同價格, 藉以將消 費者區分成不同群體, 初始訂價較高, 廠商趁機奪取對產品需求高且不願意等待的消費者剩餘, 之後, 再逐漸降價, 以迎合其它大眾市場.Eva Airlines has two potential customers: Jane and Elizabeth. Jane s demand function is P X where P is the unit price and X is quantity demanded. Elizabeth s demand function is P X. Eva Airlines is the only air travel service provider to Jane and Elizabeth and its marginal cost of operation is zero. (a)if Eva Airlines can perform the first-degree price discrimination, then it will provide a total of unit of air service. (b)if Eva Airlines can perform the first degree price discrimination, then the total surplus consisting of the surpluses of Jane, Elizabeth and Eva Airlines is maximized. (c)if Eva Airlines cannot produce any form of price discrimination, then the optimal total quantity is.5. (d)if Eva Airlines can perform the third-degree price discrimination, then the optimal total quantity is.5. 解 (b)(c)(d) (a)(b):first-degree price discrimination 台大經研所 P P 0 CS J Jane X CS E Elizabeth X 完全差別取價, 廠商依據 MR MC訂價, 因 MC 0 最後一單位均衡價格 P * 0, Q * 此時社會福利達到極大化 (c) 統一訂價決策 : P X P P X P P MR X P MR X P, P X X P, P () P, 追求 Max 採 MR MC X 0 X *, P * * () P, 追求利潤最大, 採 MR MC X 0 X *. 5 P * 0.75 *.5 統一訂價下, 最適訂價為 P * 0. 75,. 5, 0. 5 X * X *

26 X *.5 利潤 *.5 (d) third-degree price discrimination MR X MR X 均衡條件為 MR MR MC X*, X* 0.5, X *.5, P*, P* Unlike a competitive firm, a monopolist can (a)produce even if price is less than AVC. (b)continue to operate in the short run if total revenues are less than total variable costs. (c)continue to earn economic profits in the short run. (d)be assured of earning profits in the short run. 政大財管所 解 (c) (c) 獨占廠商若在短期有經濟利潤則會持續下去 完全競爭廠商若在短期有經濟利潤則會吸引新廠加入 使利潤消失 (a)(b) 二者在 TR TVC 或 P AVC 時均不會繼續生產 5.假定獨占廠商的總成本為 C 0 0Q 所面臨的市場需求為 Q 80 P 則獨占者為追求最大利潤 所導致的社會無謂損失為多少 (A)450 (B)400 (C)50 (D)00 逢甲財金所 解 (A) 獨占廠商依 MR MC 訂價 80 Q 0 Q 60, Q* 0, P* 50 完競市場依 P MC訂價 80 Q 0 Q* 60, P* 0 P 80 d c 50 0 b e a 獨占廠商的總剩餘 acde 造成 abc 的無謂損失 MC Q 80 P Q 80 MR 0 完競廠商的總剩餘 dbe 某獨占廠商生產函數為 Q min L, K 需求函數為 P 00 Q L 與 K 之價格分別為 w 4 r abc (50 0) (60 0) 社會的 deadweight loss 是 (a).6 (b)4.4 (c)6.6 (d)6.4 (e)4.6 (f)6.5 (g).4 台大經濟所 解 (c) step 先計算廠商成本函數 均衡時 Q K L L* Q, K * Q, C 4Q Q, MC 4 4Q step 計算無謂損失 P a MC c 68 4 b 6 96 MR 5 96 (84 68) 6 5 DL abc Q 00 P AR

27 7.A car company that advertises that its products have a five-year 50,000 mile warranty is practicing (a)signaling. (b)speculation. (c)hoarding (d)hedging. (e)insurance sales. 成大財金所 解.. (a); 汽車公司提供 5 年或 50,000 mile 的保證可避免資訊不對稱中 逆選擇 的問題, 其提供消費者較多 的銷售保證, 以避免消費者因怕買到性能不好的車而退出市場 因此汽車公司提供高級保證, 是一種訊號 機制, 強調只有高品質的汽車才有此種保證 8.() 若台電面對的市場需求為 Q 00 P, 且長期總成本 LTC, 試問 : 當執行完全差別取價時, 50 台電的產出為何? (A)0 (B)75 (C)50(D)40 (E) 以上皆非 () 承上題, 台電公司之利潤? (A) (B)96 (C) 65 (D) 49 (E) 以上皆非 () 承上題, 社會總剩餘? (A (B) 96 (C) 65 (D) 49 輔大金融 解 :()C; P = LMC Q 00 Q 50 Q 50Q ( Q 50)( Q 00) 0 Q * ()B; (00 Q) dq ()B; W CS PS Q 9. 以下說法何者為偽? (A) 自然獨占的出現原因很多, 其中可能的原因為規模經濟的出現 (B) 獨占廠商的出現將使價格高於邊際成本, 必然不能達到最大經濟效率 (C) 在完全差別取價的情況下, 消費者剩餘完全變成生產者剩餘 (D) 在有 進入障礙 的情況下, 得占廠商有可能長期保有超額利潤 95 中央產經 解 :(B); 完全價格歧視的獨占廠商在 P = MC 下, 將具有經濟效率 0. 假設某ㄧ家廠商為獨賣廠商, 本來是根據 MR = MC 採取單一定價來追求最大利潤, 現若改採第ㄧ級或完全差別取價來增加其利潤, 則此定價行為必將導致社會福利降低 94 政大經濟 解 : 錯 ; 當獨占者採取完全價格歧視時, 將生產在 P = MC 處, 不但使其利潤達到最大且使社會福利達到最大 P. 甲為獨占市場, 消費者有學生和上班族兩類 學生市場的需求函數為 : q 50 上班族的市場需求為 : q 00 P P, i qi分別為價格與需求量 令 q 代表甲的總銷售量, q q q 甲的總成本函數為 TC( q) q 甲可以藉由檢驗學生證, 區分消費者的身分 他考慮如何在兩市場定價來極大利潤 (A) 學生市場的邊際收入函數為 : MR( q) 00 4q (B) 學生市場的邊際收入函數為 : MR( q) 50 q (C) 上班族市場的邊際收入函數為 : MR( q) 00 q (D) 上班族市場的邊際收入函數為 : MR( q) 00 q (E) 以上皆非 94 台大經濟 解 :(A)

28 .承續上題 甲會將生產的 q 單位配置在兩市場來極大化總收入 TR(q) 令 MR(q) dtr(q) / dq (A) q q q (B) q (C)MR(q) = 00 q / (D)MR(q) = 00 4q / (E)q = 0 94 台大經濟 解 (B) ( D).承續前兩題 本小題將甲的生產成本納入考慮 請問甲極大化利潤時 下列何者為真 (, 為最適決策下 兩市場的需求價格彈性絕對值 ) (A) p p (B) p p (C) (D) 94 台大經濟 (E)q = 0 解 (B) (D) (E) 4.追求利潤最大化的獨占廠商不可能在最小效率規模下從事生產(minimum efficient scale) 7.政府通常為了保護消費者 會採取有效的上限限價政策 請問此種限價政策對完全競爭市場及獨占市 場會產生何種效果 (A)若該財貨為完全競爭市場 則消費者剩餘會因而增加 (B)若該財貨為完全競爭市場 則社會福利會因而減少 (C)若該財貨為獨占市場 則消費者剩餘會因而減少 (D)若該財貨為獨占市場 則生 產者剩餘會因而增加 (E)若該財貨為獨占市場 則社會福利會因而減少 9 北大經濟 解 B 4.If marginal revenue is less than price for a firm, it must be true that the firm (A) is a monopoly (B) is in perfect competition (C) is in monopolistic competition (D) faces a perfectly elastic demand curve (E) faces a downward-sloping demand curve 9 成大財金 解: E 只要廠商具有訂價能力 在面對一條負斜率的市場需求線下 必具有 P > MR 之性質 MR P q dp dq 在 dp 0 P > MR dq 44.Suppose an unregulated monopolist face a straight-line demand curve, which has unitary at an output level of 8,000 units, which sell for $50 each. The marginal revenue of the firm at this level of output is (A)$50 (B) 0 (C)$5 (D)indeterminate 95 中央產經 解: B MR P( ) 在 E d 時 MR = 0 Ed 45.If the demand for its product is inelastic, a monopoly s (A) marginal revenue is equal to zero (B) marginal revenue is negative (C) total revenue increases when the firm lowers its price (D) total revenue is unchanged when the firm lowers its price 解: B MR P( 95 政大經濟 ) 當 E d 時 MR < 0 Ed 46.Companies A and B are going to merge. The government regulation agency suspects that this merge may reduce the competition, which creates an unfair market. The CEOs from both companies argue that there will be no reduction in competition since their products are different and the actual market situation is that the demand of company B s product increase 5% when the price of company A s product increase 0%. 95 成大國企 解: False 當 A 產品價格上漲 0% 會使 B 產品的需求增加 5%時 表示 A 與 B 為消費上的替代品 當

29 二個互為替代性產品合併時, 將會因替代品的減少而使商品獨占性提高 49.Which of the following statements regarding a monopolist s profit maximizing condition is false? (A) The monopolist s profit maximizing price will be greater than marginal cost for the last unit supplied. (B) A monopolist can earn positive economic profit. (C) Because monopoly price is above marginal cost and a monopoly earns positive economic profit, there are no benefits to consumers in the monopoly market. (D) Price equals average revenue at the profit maximizing quantity of output. 94 成大財金 解 : C; 獨占者雖然會剝削消費者, 使消費者剩餘減少, 但在獨占均衡時仍具有消費者剩餘 ( 注意 :(B) 獨占 者能 (can) 賺取超額利潤, 但不一定具有超額利潤 ) 50.If a firm is a monopolist that seeks to maximize its profits, it will sell its output at a price (A) at which the elasticity of the demand is less than one. (B) at which the elasticity of demand is greater than one (C) that equals the marginal cost of the desired level of output (D) at which marginal revenue is negative 9 中央產經 d 解 : B; 對一個採取 single price policy 的獨占廠商, 其在 MC > 0 下必在 E 處進行銷售 5.The AMT Company faces a linear demand curve. Currently, it is selling at a price and quantity where its demand elasticity is.5. Consultants have suggested that the company expand output because it is facing an elastic demand curve. Do you agree with this recommendation? Explain. 朝陽財金 保險 企管 d 解 : 對一個面對負斜率之直線需求曲線的獨占廠商而言, 在 MC > 0 下, 其最適決策必生產在 E 之處 當廠商已經達到利潤最大 (MR = MC) 之生產時, 此時廠商若再增加產出, 雖會使總收益增加, 但總成本的 增幅更高, 反而會使利潤降低 但若廠商原產出正處於 MR > MC 處, 表示未達到利潤極大之選擇, 此時 廠商即可透過產出增加來提高利潤 5.A profit-maximizing monopolist (A) never produces on the inelastic portion of the demand curve because is can increase profit by increasing output (B) never produces on the inelastic portion of the demand curve because marginal revenue exceeds marginal cost (C) always produces on the inelastic portion of the demand curve (D) never produces on the elastic portion of the demand curve because there are no substitutes for the good it produces (E) never produces on the inelastic portion of the demand curve because marginal revenue is negative there 9 成大財金 d 解 : E; 對於進行 single price policy 的獨占廠商, 在 MC 0 下絕不會生產在 E 之階段, 此係因在 d d E 之階段恰好對應 MR < 0, 而獨占者之最適決策必為 MR MC 0, 故絕不會生產在 E 之階 段 54.Suppose that the wage rate of workers in a monopolistic firm has increased. Labor is variable factor of production. Also suppose that there has been a decrease in demand for the monopolist s product. These two factors will cause profit-maximizing price and output to change in which of the following way? (A) (B) the effect on price is unknown, output will decrease The effect on output is unknown, price will increase

30 解 : A (C) Price and output will increase to cover the higher labor cost (D) Price and output are unchanged 9 中央產經 58.A single-price monopolist produces a quantity than a perfectly competitive industry with the same costs and charges a price than the perfectly competitive industry. (A) lesser, lower (B) greater, higher (C) lesser, higher (D) greater, lower 解 : C 政大經濟 60.A monopolist gas decreasing average cost output increases. If the monopolist sets piece equal to average cost, it will (A)face excess demand. (B)lose money. (C)produce too little output from the standpoint of efficiency. (D)maximize its profits. 94 元智財金 解 : C; 對自然獨占廠商而言, 平均成本定價下的產量會小於邊際成本定價下的產量 6.A monopolist is operating at an output level where ( is the elasticity of demand ). The government imposes a quantity tax of $ per unit of output. If the demand curve facing the monopolist is linear, and the marginal cost is a constant. How much dose the price rise 朝陽財金 解 : 市場需求曲線為直線且邊際成本固定時, 每課徵一元的從量稅, 就會使商品價格上漲 / 元 6.A profit-maximizing monopolist faces the demand curve. q = 00 p. It produces at a constant marginal cost of $0 per unit. A quantity tax of $0 per unit is imposed on the monopolist s product. The price of the monopolist s product (A) rises by $5.(B) rises by $0. (C) rises by $0. (D) rises by $. 94 元智財金 解 : A; 市場需求曲線為直線且邊際成本固定時, 每課徵一元的從量稅, 就會使商品價格上漲 / 元, 所以 每課徵 0 元的從量稅, 商品價格會上漲 5 元 6.A monopolist has a cost function given byc( y) y and faces a demand curve given by P(y) = 0 y. Which statement(s) is(are) correct in the following?(a)if there is no tax on this monopolist, its profit-maximization level of output would be 5.(B)If there is no tax on this monopolist, the monopolist would charge the price $00 per unit to maximize its profit.(c)if there is a lump sum tax of $00 on this monopolist, its output would be 0 to maximize its profit. (D)If there is a specific tax on the monopolist of $0 per unit output, its output would be 5 to maximize its profit. (E)None of above. 台大經濟 解 : (B) (C) (D) (A) 稅前利潤極大化 : MR = MC y = 0,P = 00 (C) 課徵定額稅並不會影響廠商的最適決策 (D) 從量下的最適決策 : 將從量税代入生產的成本中最利潤極大化 MR = MC y = 5,P = Suppose the profit-maximizing monopolist experiences an increase in the demand for its product. Also, suppose that property tax (a fixed cost) are increased. In the short run, we may conclude that (A)both price and output will increase. (B)price will increase, but output will remain the same. (C)price will increase, but the effect on output is unknown. (D)neither price nor quantity will change because the firm will continue to produce where MR = MC. 經 9 中央產

31 解: (A) 65.Advertising by firms in monopolistic competition(a)can persuade customers that product differentiation exists.(b)provides consumers with no useful information.(c)wastes resources because the entry of rivals forces firms to be price takers.(d)does not occur. 9 政大經濟 解: (A) 在獨占性競爭市場中廣告是形成商品差異化的來源 Price and costs (dollars per unit) 66.() MC 50 ATC D Quantity (unit per day) The figure above shows the demand and cost curve for a single-price monopolist. If the firms is a profit maximizer, it will produce units and set a price of per unit. (a)5 ;$0 (b)0 ;$0 (c)0 ;$0 (d)none of the above answer are correct. ()The figure above shows the demand and cost curves for a single-price monopolist. If the firms is a profit maximizer, its economic profits will equal (a)$50 (b)$0 (c)$00 (d)$00 成 大企研所 解 ()(b) 獨占廠商依 MR MC 決定生產數量 Q* 0 在 Q * 的產量下依其所對應的需求曲線價格訂價 P * 0 ()(d) PQ TC 下列敘述何者正確 (A)獨占廠商的短期供給線為平均變動成本線(AVC)最低點以上的短期邊際成本 線 (B)獨占廠商有可能在長期平均成本最低點生產 (C)獨占廠商一定在需求彈性大於 的階段生產 (D)(B), (C)都是正確的 (E)(A), (C)都是正確的 政大科管所 解 (D) 68.假設某獨占廠商在利潤最大時的需求價格彈性為 且邊際成本為$00 試問其利潤最大的定價為多 少 (A)$00 (B)$50 (C)$00 (D)$50 (E)$00 政大科管 解 (B) P d MC P (.5)(00) A Monopolist is operating at an output level where. The government imposes a quantity tax of $6 per unit of output. If the demand curve facing the monopolist is linear, how much does the price rise? 中央企研所 t 9 解 P