经济学基础第三版习题答案

第一章经济学概述一、概念识记答案详见教材。

二、单项选择1.A，2.C，3.B，4.B，5.C，6.D，7.D，8.C，9.B，10.D三、多项选择1.BD，2.AC，3.AC，4.AD，5.ABCD，6.BC，7.ABCD，8.BCD，9.ABC，10.ABC四、判断1.×，2.√，3.×，4.×，5.×，6.×，7.×，8.×，9.×，10.√五、简答答案详见教材。

六、应用1.市场运行图如图1-1所示。

2.生产可能性曲线如图1-2所示。

函数式为Y=80-1.25X。

多读6页经济学的机会成本是放弃读7.5页心理学。

经济学基础（第3版·高职）3.（1）会计成本计算提示：列出在大学期间发生的与学习相关的明细费用项目及金额，汇总明细项目金额即得读大学的会计成本。

（2）机会成本计算提示：列出因读大学所放弃的各种选择机会，预计各种选择的可能收益，取其中最大值作为读大学的机会成本。

4.一般来说，城里人生养孩子要放弃更高的薪水和升迁机会，生养孩子的机会成本高于农村人。

5.答案略。

6.答案略。

第二章供求与价格理论一、概念识记答案详见教材。

二、单项选择1.B，2.A，3.C，4.A，5.D，6.B，7.C，8.B，9.A，10.B三、多项选择1.AB，2.ACD，3.BD，4.AD，5.CD，6.AD，7.BC，8.ABCD，9.ABC，10.BCD四、判断1.√，2.√，3.√，4.×，5.×，6.×，7.×，8.√，9.×，10.√五、简答练习题参考答案1～5，答案详见教材。

6.富有弹性的商品，宜用低价策略；缺乏弹性的商品宜用高价策略。

六、应用1.（1）Q d =Q s ，30 000－20P =5 000+5P ，P=1 000(元/吨) （2）Q e =30 000－20×1 000=10 000(吨)（3）最高限价导致商品供不应求，产生短缺，影响程度为： Q d -Q s =30 000-20×400-5 000-5×400=15 000(吨) （4）均衡图如图2-1所示。

第一章练习与答案此答案有很多这是提示，具体的可以从课本中找。

而且重点标记的是考试常考的！1．为什么说在决定生产和消费时，相对价格比绝对价格更重要？答案提示：当生产处于生产边界线上，资源则得到了充分利用，这时，要想增加某一产品的生产，必须降低另一产品的生产，也就是说，增加某一产品的生产是有机会机本（或社会成本）的。

生产可能性边界上任何一点都表示生产效率和充分就业得以实现，但究竟选择哪一点，则还要看两个商品的相对价格，即它们在市场上的交换比率。

相对价格等于机会成本时，生产点在生产可能性边界上的位置也就确定了。

所以，在决定生产和消费时，相对价格比绝对价格更重要。

2．仿效图1—6和图1—7，试推导出Y商品的国民供给曲线和国民需求曲线。

答案提示：3．在只有两种商品的情况下，当一个商品达到均衡时，另外一个商品是否也同时达到均衡？试解释原因。

答案提示：4．如果生产可能性边界是一条直线，试确定过剩供给（或需求）曲线。

答案提示：5．如果改用Y商品的过剩供给曲线（B国）和过剩需求曲线（A国）来确定国际均衡价格，那么所得出的结果与图1—13中的结果是否一致？答案提示：国际均衡价格将依旧处于贸易前两国相对价格的中间某点。

6．说明贸易条件变化如何影响国际贸易利益在两国间的分配。

答案提示：一国出口产品价格的相对上升意味着此国可以用较少的出口换得较多的进口产品，有利于此国贸易利益的获得，不过，出口价格上升将不利于出口数量的增加，有损于出口国的贸易利益；与此类似，出口商品价格的下降有利于出口商品数量的增加，但是这意味着此国用较多的出口换得较少的进口产品。

对于进口国来讲，贸易条件变化对国际贸易利益的影响是相反的。

7．如果国际贸易发生在一个大国和一个小国之间，那么贸易后，国际相对价格更接近于哪一个国家在封闭下的相对价格水平？答案提示：贸易后，国际相对价格将更接近于大国在封闭下的相对价格水平。

8．根据上一题的答案，你认为哪个国家在国际贸易中福利改善程度更为明显些？答案提示：小国。

经济学基础习题目录第一章导论 (3)一、单项选择题 (3)二、多项选择题 (5)三、判断题 (6)四、案例 (7)五、实训项目 (7)第二章需求、供给与均衡价格 (8)一、单项选择题 (8)二、多项选择题 (10)三、判断题 (11)四、案例 (12)五、实训项目 (14)第三章消费者行为分析 (14)一、单项选择题 (14)二、多项选择题 (16)四、案例 (17)五、实训项目 (18)第四章生产理论 (18)一、单项选择题 (18)二、多项选择题 (20)三、判断题 (21)四、案例 (22)五、实训项目 (23)第五章成本理论 (24)一、单项选择题 (24)二、多项选择题 (26)三、判断题 (27)四、案例 (28)五、实训项目 (30)第六章市场与竞争分析 (30)一、单项选择题 (30)二、多项选择题 (32)三、判断题 (33)四、案例 (33)第七章生产要素理论 (34)一、单项选择题 (34)二.多项选择题 (36)三.判断正误题 (38)四、案例 (39)五、实训项目 (41)第八章国民收入的核算 (41)一、单项选择题 (41)二、多项选择题 (43)三、判断题 (45)四、案例 (46)五、实训项目 (48)第九章国民收入的决定理论 (49)一、单项选择题 (49)二、多项选择题 (50)三、判断题 (51)四、案例 (52)五、实训项目 (57)第十章经济周期与经济增长 (57)一、单项选择题 (57)二、多项选择题 (59)三、判断题 (61)四、案例 (61)五、实训项目 (63)第十一章通货膨胀与失业 (63)一、单项选择题 (63)二、多项选择题 (66)三、判断题 (67)四、案例 (68)五、实训项目 (68)第十二章宏观经济政策 (68)一、单项选择题 (68)二、多项选择题 (70)三、判断题 (71)四、案例 (72)五、实训项目 (75)经济学基础习题第一章导论一、单项选择题1.在任何一个经济中，（ C ）。

第三章 消费者选择第一部分 教材配套习题本习题详解１．已知一件衬衫的价格为８０元，一份肯德基快餐的价格为２０元，在某消费者关于这两种商品的效用最大化的均衡点上，一份肯德基快餐去替代衬衫的边际替代率ＭＲＳ是多少？解答：用 Ｘ 表示肯德基快餐的份数；Ｙ 表示衬衫的件数；ＭＲＳＸＹ 表示在 维持效用水平不变的前提下，消费者增加一份肯德基快餐消费时所需要放弃的衬衫的消费数量。

在该消费者实现关于这两种商品的效用最大化时，在均衡点上有边际替代率等于价格比，则有：201804X XY Y P Y MRS X P ∆=-===∆ 它表明，在效用最大化的均衡点上，该消费者关于一份肯德基快餐对衬衫 的边际替代率ＭＲＳ为0.25。

２．假设某消费者的均衡如图３—2１所示。

其中，横轴ＯＸ１和纵轴ＯＸ２分别表示商品１和商品２的数量，线段ＡＢ为消费者的预算线，曲线Ｕ 为消费者的无差异曲线，Ｅ点为效用最大化的均衡点。

已知商品１的价格Ｐ１＝２元。

求: （１）求消费者的收入； （２）求商品２的价格Ｐ２； （３）写出预算线方程； （４）求预算线的斜率； （５）求Ｅ点的ＭＲＳ1２的值。

图３—2１ 某消费者的均衡解答：（１）横轴截距表示消费者的收入全部购买商品１的数量为３０单位，且已知Ｐ１＝２元，所以，消费者的收入 Ｍ＝２×３０＝６０元。

（２）图３—１中纵轴截距表示消费者的收入全部购买商品２的数量为２０单位，且由（１）已知收入 Ｍ＝６０元，所以，商品２的价格P 2＝M 20＝6020＝3（元）。

（３）由于预算线方程的一般形式为 P 1X 1＋P 2X 2＝M,所以本题预算线方程具体写为：2X 1＋3X 2＝60。

（４）(4)将(3)中的预算线方程进一步整理为X 2＝－23X 1＋20。

所以，预算线的斜率为－23。

(5)在消费者效用最大化的均衡点E 上，有211212X PMRS X P ∆=-=∆，即无差异曲线斜率的绝对值即MRS 等于预算线斜率的绝对值P 1P 2。

《金融基础》习题参考答案项目一：一、单项选择题1、与货币的出现紧密相联的是（ B ）A、金银的稀缺性B、交换产生与发展C、国家的强制力D、先哲的智慧2、商品价值形式最终演变的结果是（ D ）A、简单价值形式B、扩大价值形式C、一般价值形式D、货币价值形式3、当今世界各国普遍采用的是哪种货币形态？（ D ）A、实物货币B、金属货币C、代用货币D、信用货币4、在下列货币制度中劣币驱逐良币律出现在（C ）A、金本位制B、银本位制C、金银复本位制D、金汇兑本位制5、代用货币与信用货币的区别在于（C）A、货币的材质是否是纸质B、是否可以铸造C、是否有十足的贵金属准备D、自身价值和货币面值是否一致6．在金属货币流通的条件下，单位货币的法定含金量被作为（ A ）。

A．货币的价格标准B．货币单位C．货币名称D．货币材料7．典型的金本位制是（ D ）。

A．金块本位制B．金汇兑本位制C．虚金本位制D．金币本位制8、在偿还债务中发挥的作用主要货币职能是（ C ）A、价值尺度B、流通手段C、支付手段D、贮藏手段9、货币执行（A ）职能时可以采用观念上的货币，而不必采用现实的货币。

A、价值尺度B、流通手段C、支付手段D、贮藏手段10、马克思认为货币的本质特征是充当（ B ）A、特殊等价物B、一般等价物C、普通商品D、特殊商品二、多项选择题1、一般而言，要求作为货币的商品具有如下特征（ ACDE ）A、价值比较高B、金属的一种C、易于分割D、易于保存E、便于携带2、最早出现的实物货币形态包括（ AE ）A、贝壳B、黄金C、白银D、铜铁E、牲畜3．信用货币制度的特点有（BCE ）。

A．黄金作为货币发行的准备B．贵金属非货币化C．国家强制力保证货币的流通D．金银储备保证货币的可兑换性E．货币发行通过信用渠道4、货币支付手段职能发挥作用的情形有（ ABCDE ）A、赋税B、各种劳动报酬C、国家财政D、银行信用E、房租5、对本位币的理解正确的是（ ACDE ）A、本位币是一国的基本通货B、本位币具有有限法偿性C、本位币具有无限法偿D、本位币的最小规格是一个货币单位E、货币本位制度的名称取决于本位币币材的名称。

经济学基础(第三版)课后参考答案第一章经济学的基本概念1. 经济学是研究人们如何分配有限的资源来满足无限的需求的一门学科。

它包括如何分配资源，如何决定价格，如何确定收入，如何影响和调节供求关系，以及如何分析和评估政府的经济政策。

2. 经济学的基本原理包括：(1) 供求原理：当价格上升时，供应量减少，需求量增加；当价格下降时，供应量增加，需求量减少。

(2) 收入效应：当收入增加时，需求量增加；当收入减少时，需求量减少。

(3) 同质性效应：当价格上升时，对于同一商品的需求量减少；当价格下降时，对于同一商品的需求量增加。

(4) 替代性效应：当价格上升时，对于一种商品的需求量减少，而对另一种商品的需求量增加；当价格下降时，对于一种商品的需求量增加，而对另一种商品的需求量减少。

3. 经济学的两个基本问题是：(1) 如何分配有限的资源来满足无限的需求。

(2) 如何决定价格。

4. 经济学的三个基本方法是：(1) 比较分析法：这种方法通过比较不同经济体之间的差异来研究经济问题。

(2) 实证分析法：这种方法通过实证数据来衡量不同变量之间的关系，以此来研究经济问题。

(3) 模型分析法：这种方法通过分析不同变量之间的关系来说明经济问题的本质。

5. 经济学的三个主要分支是：(1) 微观经济学：这是一门关于个体或小团体如何分配有限资源来满足无限需求的学科。

它包括如何决定价格、如何影响供求关系、如何影响市场竞争、如何决定企业的生产效率、以及企业如何进行市场营销等。

(2) 宏观经济学：这是一门关于整个国家或地区如何分配有限资源来满足无限需求的学科。

它包括如何影响国民总收入、如何影响国民总产出、如何影响通货膨胀、如何影响失业率、以及如何分析和评估政府的经济政策等。

(3) 社会经济学：这是一门关于整个国家或地区如何分配有限资源来促进公平、正义和可持续发展的学科。

它包括如何影响人民生活水平、如何促进包容性发展、如何保障人权、以及如何应对气候变化、能源危机、贫困问题、人口问题等。

西经课后答案第二章一、思考题1.什么是需求和供给？影响需求和供给变化的因素有哪些？1.答：（1）需求(Demand)是指消费者在某个价格水平下愿意并且能够购买的商品或劳务的数量，它以消费者的支付能力为基础。

对某种商品的需求是受很多因素影响的，如该商品本身的价格高低，与该商品相关商品的价格高低，消费者的收入水平，市场流行的时尚和消费者的偏好，人口以及由此决定的市场范围，历史传统、民族风俗、社会风尚、地理气候、文化习惯、消费示范和攀比、广告的影响，等等。

消费者的收入水平是影响商品需求的一个重要因素。

对多数商品来说，如果消费者的收入提高，即使价格不变，消费者也有能力在每一个价格水平上购买更多的商品。

因此，收入提高将增加对商品的需求量。

然而，对某些商品来说，情况恰好相反。

这些商品主要是穷人赖以为生的食品，如土豆、面包等等。

收入水平提高后，对这些物品的需求量反而会下降，因为当穷人变得更有钱时，他们将会更多地消费更有营养的食品，而相应地减少对价格低廉且营养较差的食品的消费。

如果一种商品的需求随着收入的增加而增加，随着收入的减少而减少，那么我们就称这种商品为正常品（normal good），如果这种商品的需求随着收入的增加而减少，随着收入的减少而增加，那么我们就称这种商品为低档品（inferior good）。

当一种商品本身的价格保持不变，而和它相关的其他商品的价格发生变动时，这种商品本身的需求量也会发生变化。

西方经济学把相关商品分为两种：替代品（substitutes）和互补品（complements）。

一种商品的替代品是指可以替代这种商品消费的另外一种商品，如茶是咖啡的替代品，猪肉是牛肉的替代品，等等。

一种商品的互补品是指必须和该商品一起消费的另外一种商品，如汽油是汽车的互补品，显示器是电脑主机的互补品，左手套是右手套的互补品，等等。

如果某种商品的替代品价格上升，那么该商品的需求增加；如果某种商品的替代品价格下降，那么该商品的需求减少。

第一章边学边练一、单项选择题１.A 2.C 3.B 4. B ５. C6.A7.B8.D9.A 10.B二、多项选择题１.ABCEF 2.BCDEF 3. BCD 4. ACD５.BD6.ABD7.AC8.BCD9.ABC 10.ABC三、判断题1.F2.F3.F4.T5.F6.T7.F8.F9.T 10.T四、简答题1.答：微观经济学研究的基本内容包括: 均衡价格理论、消费者行为理论、生产理论、分配理论、市场失灵与微观经济政策。

2.答：经济学的基本问题在于一个人类面临的矛盾，就是资源的稀缺与欲望的无限性之间的矛盾。

这一问题的解决构成了经济学研究的基本内容，因此稀缺意味着人类必须做出选择，而资源的多种用途又为这种选择提供了可能性。

这个问题是要考察你对资源稀缺性的认识，对资源的稀缺性与多种用途又为这种选择提供了可能性。

3.答：实证分析和规范分析如果仅从概念上区分是比较简单的，他们无非是回答了不同的问题，“实证分析”回答的是是什么的问题，“规范分析”回答的是“应该是什么”的问题。

在回答这些不同问题时，很显然规范分析是存在一个价值判断体系的，实证分析不存在这种价值判断体系。

五、课堂实训1.经济学企图摆脱或排斥一切价值判断，只研究经济本身的内在规律，并根据这些规律，分析和预测人们经济行为的效果。

它要回答“是什么”的问题；规范经济学以一定的价值判断为基础，提出某些标准作为分析处理经济问题的标准，树立经济理论的前提，作为制定经济政策的依据，并研究如何才能符合这些标准。

它要回答“应该是什么”的问题。

从实证经济学的角度，要研究造成农产品的减产的因素，这种减产本身是否具有什么规律，等等。

从规范经济学的角度，我们研究造纸厂造成农产品减产到底是一件好事，还是一件坏事。

具有不同价值判断标准的人对这一问题会有不同的看法。

有人从造纸厂带动地方经济增长的角度出发，认为是一件好事；有人从造纸厂对当地环境的污染和农产品的减产的角度出发，认为是一件坏事。

SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. When a competitive firm doubles the amount it sells, the price remains the same, so its totalrevenue doubles.2. The price faced by a profit-maximizing firm is equal to its marginal cost because if price were abovemarginal cost, the firm could increase profits by increasing output, while if price were belowmarginal cost, the firm could increase profits by decreasing output.A profit-maximizing firm decides to shut down in the short run when price is less than averagevariable cost. In the long run, a firm will exit a market when price is less than average total cost.3. In the long run, with free entry and exit, the price in the market is equal to both a firm’s marginalcost and its average total cost, as Figure 1 shows. The firm chooses its quantity so that marginal cost equals price; doing so ensures that the firm is maximizing its profit. In the long run, entry into and exit from the industry drive the price of the good to the minimum point on theaverage-total-cost curve.Figure 1Questions for Review1. A competitive firm is a firm in a market in which: (1) there are many buyers and many sellers inthe market; (2) the goods offered by the various sellers are largely the same; and (3) usually firms can freely enter or exit the market.2. Figure 2 shows the cost curves for a typical firm. For a given price (such as P*), the level of outputthat maximizes profit is the output where marginal cost equals price (Q*), as long as price is greater than average variable cost at that point (in the short run), or greater than average total cost (in the long run).Figure 23. A firm will shut down temporarily if the revenue it would get from producing is less than thevariable costs of production. This occurs if price is less than average variable cost.4. A firm will exit a market if the revenue it would get if it stayed in business is less than its total cost.This occurs if price is less than average total cost.5. A firm's price equals marginal cost in both the short run and the long run. In both the short runand the long run, price equals marginal revenue. The firm should increase output as long asmarginal revenue exceeds marginal cost, and reduce output if marginal revenue is less thanmarginal cost. Profits are maximized when marginal revenue equals marginal cost.6. The firm's price equals the minimum of average total cost only in the long run. In the short run,price may be greater than average total cost, in which case the firm is making profits, or price may be less than average total cost, in which case the firm is making losses. But the situation isdifferent in the long run. If firms are making profits, other firms will enter the industry, which will lower the price of the good. If firms are making losses, they will exit the industry, which will raise the price of the good. Entry or exit continues until firms are making neither profits nor losses. At that point, price equals average total cost.7. Market supply curves are typically more elastic in the long run than in the short run. In acompetitive market, since entry or exit occurs until price equals the minimum of average total cost, the supply curve is perfectly elastic in the long run.Problems and Applications1. A competitive market is one in which: (1) there are many buyers and many sellers in the market;(2) the goods offered by the various sellers are largely the same; and (3) usually firms can freelyenter or exit the market. Of these goods, bottled water is probably the closest to a competitive market. Tap water is a natural monopoly because there's only one seller. Cola and beer are not perfectly competitive because every brand is slightly different.2. Since a new customer is offering to pay $300 for one dose, marginal revenue between 200 and 201doses is $300. So we must find out if marginal cost is greater than or less than $300. To do this, calculate total cost for 200 doses and 201 doses, and calculate the increase in total cost.Multiplying quantity by average total cost, we find that total cost rises from $40,000 to $40,401, so marginal cost is $401. So your roommate should not make the additional dose.3. a. Remembering that price equals marginal cost when firms are maximizing profit, we knowthe marginal cost must be 30 cents, since that is the price.b. The industry is not in long-run equilibrium since price exceeds average total cost.4. Once you have ordered the dinner, its cost is sunk, so it does not represent an opportunity cost.As a result, the cost of the dinner should not influence your decision about stuffing yourself.5. Since Bob’s average total cost is $280/10 = $28, which is greater than the price, he will exit theindustry in the long run. Since fixed cost is $30, average variable cost is ($280 - $30)/10 = $25, which is less than price, so Bob won’t shut down in the short run.6. Here’s the table showing costs, revenues, and profits:a. The firm should produce 5 or 6 units to maximize profit.b. Marginal revenue and marginal cost are graphed in Figure 3. The curves cross at aquantity between 5 and 6 units, yielding the same answer as in part (a).c. This industry is competitive since marginal revenue is the same for each quantity. Theindustry is not in long-run equilibrium, since profit is positive.Figure 37. a. Figure 4 shows the short-run effect of declining demand for beef. The shift of theindustry demand curve from D1 to D2 reduces the quantity from Q1 to Q2 and reduces theprice from P1 to P2. This affects the firm, reducing its quantity from q1 to q2. Before thedecline in the price, the firm was making zero profits; afterwards, profits are negative, asaverage total cost exceeds price.Figure 4b. Figure 5 shows the long-run effect of declining demand for beef. Since firms were losingmoney in the short run, some firms leave the industry. This shifts the supply curve fromS1 to S3. The shift of the supply curve is just enough to increase the price back to itsoriginal level, P1. As a result, industry output falls still further, to Q3. For firms thatremain in the industry, the rise in the price to P1 returns them to their original situation,producing quantity q1 and earning zero profits.Figure 58. Figure 6 shows that although high prices cause an industry to expand, entry into the industryeventually returns prices to the point of minimum average total cost. In the figure, the industry is originally in long-run equilibrium. The industry produces output Q1, where supply curve S1intersects demand curve D1, and the price is P1. At this point the typical firm produces output q1.Since price equals average total cost at that point, the firm makes zero economic profit.Now suppose an increase in demand occurs, with the demand curve shifting to D2. This causes "high prices" in the industry, as the price rises to P2. It also causes the industry to increase output to Q2. With the higher price, the typical firm increases its output from q1 to q2, and now makes positive profits, since price exceeds average total cost.However, the positive profits that firms earn encourage other firms to enter the industry. Their entry, "an expansion in an industry," leads the supply curve to shift to S3. The new equilibrium reduces the price back to P1, "bringing an end to high prices and manufacturers' prosperity," since now firms produce q1 and earn zero profit again. The only long-lasting effect is that industryoutput is Q3, a higher level than originally.Figure 69. a. Figure 7 shows the typical firm in the industry, with average total cost ATC1, marginal costMC1, and price P1.b. The new process reduces Hi-Tech’s marginal cost to MC2 and its average total cost to ATC2,but the price remains at P1 since other firms cannot use the new process. Thus Hi-Techearns positive profits.c. When the patent expires and other firms are free to use the technology, all firms’average-total-cost curves decline to ATC2, so the market price falls to P3 and firms earn noprofits.Figure 710. The rise in the price of petroleum increases production costs for individual firms and thus shifts theindustry supply curve up, as shown in Figure 8. The typical firm's initial marginal-cost curve is MC1 and its average-total-cost curve is ATC1. In the initial equilibrium, the industry supply curve, S1, intersects the demand curve at price P1, which is equal to the minimum average total cost of the typical firm. Thus the typical firm earns no economic profit.The increase in the price of oil shifts the typical firm's cost curves up to MC2 and ATC2, and shifts the industry supply curve up to S2. The equilibrium price rises from P1 to P2, but the price does not increase by as much as the increase in marginal cost for the firm. As a result, price is less than average total cost for the firm, so profits are negative.In the long run, the negative profits lead some firms to exit the industry. As they do so, theindustry-supply curve shifts to the left. This continues until the price rises to equal the minimum point on the firm's average-total-cost curve. The long-run equilibrium occurs with supply curve S3, equilibrium price P3, industry output Q3, and firm's output q3. Thus, in the long run, profits arezero again and there are fewer firms in the industry.Figure 811. a. Figure 9 illustrates the situation in the U.S. textile industry. With no international trade,the market is in long-run equilibrium. Supply intersects demand at quantity Q1 and price$30, with a typical firm producing output q1.Figure 9b. The effect of imports at $25 is that the market supply curve follows the old supply curve upto a price of $25, then becomes horizontal at that price. As a result, demand exceedsdomestic supply, so the country imports textiles from other countries. The typicaldomestic firm now reduces its output from q1 to q2, incurring losses, since the large fixedcosts imply that average total cost will be much higher than the price.c. In the long run, domestic firms will be unable to compete with foreign firms because theircosts are too high. All the domestic firms will exit the industry and other countries willsupply enough to satisfy the entire domestic demand.12. a. Figure 10 shows the current equilibrium in the market for pretzels. The supply curve, S1,intersects the demand curve at price P1. Each stand produces quantity q1 of pretzels, sothe total number of pretzels produced is 1,000 x q1. Stands earn zero profit, since priceequals average total cost.b. If the city government restricts the number of pretzel stands to 800, the industry-supplycurve shifts to S2. The market price rises to P2, and individual firms produce output q2.Industry output is now 800 x q2. Now the price exceeds average total cost, so each firm ismaking a positive profit. Without restrictions on the market, this would induce other firmsto enter the market, but they cannot, since the government has limited the number oflicenses.c. The city could charge a license fee for the licenses. Since it is a lump-sum fee for thelicense, not based on the quantity of sales, such a tax has no effect on marginal cost, sowon't affect the firm's output. It will, however, reduce the firm's profits. As long as thefirm is left with a zero or positive profit, it will continue to operate. So the license fee thatbrings the most money to the city is to charge each firm the amount (P2 - ATC2)q2, theamount of the firm's profit.Figure 1013. a. Figure 11 illustrates the gold market (industry) and a representative gold mine (firm).The demand curve, D1, intersects the supply curve at industry quantity Q1 and price P1.Since the industry is in long-run equilibrium, the price equals the minimum point on therepresentative firm's average total cost curve, so the firm produces output q1 and makeszero profit.b. The increase in jewelry demand leads to an increase in the demand for gold, shifting thedemand curve to D2. In the short run, the price rises to P2, industry output rises to Q2,and the representative firm's output rises to q2. Since price now exceeds average totalcost, the representative firm now earns positive profits.c. Since gold mines are earning positive economic profits, over time other firms will enter theindustry. This will shift the supply curve to the right, reducing the price below P2. Butit's unlikely that the price will fall all the way back to P1, since gold is in short supply.Costs for new firms are likely to be higher than for older firms, since they'll have to discovernew gold sources. So it's likely that the long-run supply curve in the gold industry isupward sloping. That means the long-run equilibrium price will be higher than it wasinitially.Figure 1114. a. Figure 12 shows cost curves for a California refiner and a non-California refiner. Since theCalifornia refiner has access to lower-cost oil, its costs are lower.Figure 12b. In long-run equilibrium, the price is determined by the costs of non-California refiners,since California refiners cannot supply the entire market. The market price will equal theminimum average total cost of the other refiners; they will thus earn zero profits. SinceCalifornia refiners have lower costs, they will earn positive profits, equal to (P* - ATC C) xQ C.c. Yes, there is a subsidy to California refiners that is not passed on to consumers. Thesubsidy accounts for the long-run profits of the California refiners. It arises simplybecause the oil cannot be exported.。