1、 Is this outcome efficient? How do you and your roommate reach this solution?根据科斯定理，如果我被迫吸烟所承受的成本大于我的室友吸烟所获得的收益，我的室友就不应该在房间里吸烟。如果我的成本小于室友的收益，他就可以在房间里吸烟。我可以通过对他进行吸烟有害的教育，同时给他买一些糖果以缓解他不能吸烟的痛苦，来与他达成协议他以后不在房间里吸烟。6. Why do economists prefer them over regulations as a way to protect the environment from p
2、ollution?经济学家偏爱庇古税，首先是因为它减少污染更有效率。庇古税实际上规定了污染权的价格，并把污染权分配给那些减少污染成本最高的工厂。无论环境保护机构选择的污染水平是多少，它都可以用税收以最低的总成本达到这个目标。其次，庇古税对环境更有利。在管制政策下，企业被动地减少污染，一旦达到了管制的要求，它就没有理由再减少排污。税收控制激励企业主动减少污染，以尽力减少不得不为此支付的税收量。Problems and applications1. Contributions to charitable organizations are deductible under the federal
3、income tax. In what way does this government policy encourage private solutions to externalities?政府的这种政策用一种变相性的补贴方法鼓励私人解决外部性问题。免税鼓励人们向慈善组织捐款。慈善组织是私人解决外部性的方法之一，它通过对具有正外部性的行业和行为资助，使外部性内在化。2. Ringo loves playing rock and roll music at high volume. Luciano loves opera and hates rock and roll. Unfortunat
4、ely, they are next-door neighbors in an apartment building with paperthin walls.a. What is the externality here?b. What command-and-control policy might the landlord impose? Could such a policy lead to an inefficient outcome?c. Suppose the landlord lets the tenants do whatever they want. According t
5、o the Coase theorem, how might Ringo and Luciano reach an efficient outcome on their own? What might prevent them from reaching an efficient outcome?Answer:a. 这里的外部性是：瑞格用高音量播放摇滚乐，使邻居卢西阿诺受到噪音干扰，因为卢西阿诺憎恨摇滚乐。b. 房东可以规定房客不得在房间里开大录音机、收音机或电视机的音量。这种政策可能会引起无效率的结果。它虽然使卢西阿诺避免忍受摇滚乐干扰之苦，但也使瑞格无法享受自己喜爱的音乐。如果高音量摇滚乐
6、使卢西阿诺所承受的成本小于瑞格的收益，这项政策就是无效率的。c. 根据科斯定理，瑞格和卢西阿诺可以就此事进行协商，比较他们各自的成本和收益，达成一个协议。要么，瑞格向卢西阿诺支付一定的金额以补偿卢西阿诺忍受摇滚乐的痛苦；要么，卢西阿诺向瑞格支付一定的金额以补偿瑞格不能享受自己喜爱的音乐的损失。但达成协议有时是很困难的。有时会因为高昂的交易成本使谈判无法进行；有时会因为各方都竭力要达到更好的交易而使谈判破裂。假设瑞格从听摇滚乐中得到400美元收益，而卢西阿诺由于听摇滚乐要承受700美元的成本。虽然瑞格放弃听高音量的摇滚乐，同时卢西阿诺向他进行支付是有效率的，但是，如果瑞格想要600美元，而卢西阿
7、诺只愿支付500美元。当他们就价格争执时，摇滚乐仍然以响亮的声音在公寓楼里回荡。3. It is rumored that the Swiss government subsidizes cattle farming, and that the subsidy is larger in areas with more tourist attractions. Can you think of a reason why this policy might be efficient?这种政策使旅游业的外部性内在化。旅游者多的地方，当地的养牛业必然受到不良影响。为了将养牛业维持在一个合意的水平，瑞士
8、政府给予其补贴，而且越是受旅游业的负外部性影响大的地区，补贴越多。这种政策是有效率的。4. Greater consumption of alcohol leads to more motor vehicle accidents and, thus, imposes costs on people who do not drink and drive.a. Illustrate the market for alcohol, labeling the demand curve, the social-value curve, the supply curve, the social-cost
9、curve, the market equilibrium level of output, and the efficient level of output.b. On your graph, shade the area corresponding to the deadweight loss of the market equilibrium.（Hint: The deadweight loss occurs because some units of alcohol are consumed for which the social cost exceeds the social v
10、alue.） explain.a. 酒的消费有负外部性，它的社会价值小于其私人价值。酒的有效率产量小于市场均衡时的产量。b.图10-3中的阴影部分就是市场均衡产生的无谓损失。酒的社会价值小于其私人价值，由社会价值和社会成本曲线决定的产量Q1对社会来说是有效率的。但是，酒市场的交易双方在交易时并不考虑消费酒所带来的负外部性，市场只按私人成本和私人价值来确定使交易双方剩余最大化的均衡销售量Q2.在Q2的水平上，酒的社会成本大于酒的社会价值，产生无谓损失。无谓损失=（单位产量的社会成本单位产量的社会价值）（均衡产量有效产量）。5. Many observers believe that the le
11、vels of pollution in our economy are too high.a. If society wishes to reduce overall pollution by a certain amount, why is it efficient to have different amounts of reduction at different firms?b. Command-and-control approaches often rely on uniform reductions among firms. Why are these approaches g
12、enerally unable to target the firms that should undertake bigger reductions?c. Economists argue that appropriate Pigovian taxes or tradable pollution rights will result in efficient pollution reduction. How do these approaches target the firms that should undertake bigger reductions?a. 不同企业减少污染的成本不同
13、，让不同企业减少不同量的污染，就像市场把不同量的物品分配给对物品评价不同的买者一样，是有效率的。b. 命令与控制方法对企业产生不了更多减少污染的激励。企业只要达到管制要求的排污量目标就完成任务了，没有理由再减少排污。而且，规定各企业统一的排污减少量并不一定是最省钱的保护环境的方法。由于不同企业减少污染需要的成本不同，要求所有企业等量减少排污是没有效率的。c. 适当的庇古税可以把污染控制在环境部门想达到的任何程度。同时，庇古税把污染权分配给那些减少污染成本最高的工厂，是有效率的方法。而且，庇古税改变了对企业减少排污的激励，企业为了减少税收支出，总会尽力减少污染以少交税。可交易的污染权利即污染许可
14、证减少污染与庇古税很相似。那些以高成本才能减少污染的企业愿意为污染许可证出最高的价格。那些以低成本可以减少污染的企业也愿意出卖他们所拥有的许可证。污染许可证成了一种稀缺资源，企业为了降低成本，提高收益，会尽量减少对这种资源的购买，或者节省这种资源，出卖给别人。这样，企业就会更多地减少污染。6. The Pristine River has two polluting firms on its banks. Acme Industrial and Creative Chemicals each dump 100 tons of glop into the river each year. The
15、 cost of reducing glop emissions per ton equals $10 for Acme and $100 for Creative. The local government wants to reduce overall pollution from 200 to 50 tons.a. If the government knew the cost of reduction for each firm, what reductions would it impose to reach its overall goal? What would be the c
16、ost to each firm and the total cost to the firms together?b. In a more typical situation, the government would not know the cost of pollution reduction at each firm. If the government decided to reach its overall goal by imposing uniform reductions on the firms, calculate the reduction made by each
17、firm, the cost to each firm, and the total cost to the firms together.c. Compare the total cost of pollution reduction in parts （a） and （b）. If the government does not know the cost of reduction for each firm, is there still some way for it to reduce pollution to 50 tons at the total cost you calcul
18、ated in part（a）? Explain.a. 应该让减少污染成本最低的企业尽量多地减少污染，雅克美公司应该减少100吨（因为它最多只排放100吨），成本是1000元。剩下的50吨让克拉梯夫公司来减少，它的成本是5000元。总成本是6000元。b. 如果政府决定通过让企业减少相同的量来达到目的，每家企业应减少75吨（1502=75）。雅克美公司的成本是750美元，克拉梯夫公司的总成本是7500美元。两家企业的总成本是8250美元。c. 采用（a）方法减少污染比采用（b）方法减少污染的总成本低。如果政府并不知道每家企业的成本，可以采用出售污染权证的方法以（a）中的总成本使污染减少到50吨
19、。给每家企业发放可排放25吨污染物的许可证，并允许许可证自由转让。雅克美公司在比较了减少污染的成本和出卖许可证的收益后，会以250美元（2510）2500美元（25100）之间的价格出售这张许可证。克拉梯夫公司也会很乐意以这个范围的价格购买这张许可证，因为许可证的价格低于它减少25吨污染的成本。7. Suppose that the government decides to issue tradable permits for a certain form of pollution.a. Does it matter for economic efficiency whether the g
20、overnment distributers or auctions the permits? Does it matter in any other ways?b. If the government chooses to distribute the permits, does the allocation of permits among firms matter for efficiency?a. 政府无论是分配还是拍卖许可证对经济效率并不重要。因为许可证是可交易的，减少污染成本高的企业会出高价从别的企业购买许可证，也可以出高价在拍卖会上买到满足自己需要量的许可证。市场最终将会以最高的
21、价格把许可证分配给对她评价最高的买者。其他方式只要是公平地发放许可证，对效率来说都是一样的。如果在许可证的取得过程中存在幕后交易或特权现象，就会使社会效率大大降低。因为污染企业必须多花一部分成本去“寻租”b. 许可证在各企业中的分配对效率不重要。许可证多余的企业可以在许可证市场上出卖多余的证，许可证缺少的企业也可以在市场上购买它所需要的量。用其他任何方式不重要，我对这一问题的解释同（a）题中的解释一样。8. The primary cause of global warming is carbon dioxide, which enters the atmosphere in varying
22、amounts from different countries but is distributed equally around the globe within a year. In an article in The Boston Globe （July 3,1990）, Martin and Kathleen Feldstein argue that the correct approach to global warming is “not to ask individual countries to stabilize their emissions of carbon diox
23、ide at current levels,” as some have suggested. Instead, they argue that “carbon dioxide emissions should be reduced in countries where the costs are least, and the countries that bear that burden should be compensated by the rest of the world.”a. Why is international cooperation necessary to reach
24、an efficient outcome?b. Is it possible to devise a compensation scheme such that all countries would be better off than under a system of uniform emission reductions?a. 有的国家减少二氧化碳排放量的成本低，有的国家成本高。成本低的国家应该减少更多的排放量，成本高的国家可以较少地减少排放量，但他们必须为自己多排放了污染物而对少排放的国家给予补偿。把污染权分配给减少污染成本最高的国家是最有效率的方法，这必须通过国际合作才能实现。b.
25、 我认为不太可能。因为这种全球性补偿牵涉到对减少二氧化碳排放量的成本的衡量标准，这个标准不易制定，衡量方法也不易制定。最后极有可能是在全球政治中占统治地位的国家获得补偿。同时，这还牵涉到历史问题。大气中二氧化碳的过量含有很大程度上是西方发达国家在工业革命时大量排放二氧化碳所造成的，西方发达国家是否应为自己的历史责任而补偿其他国家呢？9. There are three industrial firms in Happy Valley.FirmInitial Pollution LevelCost of Reducing Pollution by 1 UnitA70 units$20B8025C
26、5010The government wants to reduce pollution to 120 units, so it gives each firm 40 tradable pollution permits.a. Who sells permits and how many do they sell? Who buys permits and how many do they buy? Briefly explain why the sellers and buyers are each willing to do so. What is the total cost of po
27、llution reduction in this situation.b. How much higher would the costs of pollution reduction be if the permits could not be traded?a. 减少单位污染成本最小的厂家将出售自己的许可证，在本题中应该是C企业出售许可证。减少污染成本比C企业高的企业将购买许可证，本题中应该是A、B企业。A、B、长三家都只得到40单位污染的许可，这就意味着A、B、企业必须减少的污染量分别是：30、40、10单位。与此相对应的成本是： A：3020=600 美元 B：4025=1 000
28、美元 C：1010=100 美元（1） C可以将自己的许可证以每污染单位1020美元之间的价格出售给A30单位，C最多可得到600美元。剩下的10个污染单位，C可以以每单位1025美元的价格出售给B，C最多可得到250美元。在这种交易方法下，C最多可得600+250=850美元。（2） C也可以将40个单位的污染量全部以1025美元的价格出售给B，C最多可得4025=1 000美元。这样做的收益大于方案（1）中的收益，所以C会实施本方案，向B出售40个单位的污染许可证。 最后，A排放40单位污染，B排放80单位，C不排放污染。在这种情况下，减少污染的总成本是3020+5010=1 100美元。b. 如果许可证不能交易，减少污染的成本是3020+4025+1010=1 700美元，比A题中可交易时高出600美元（17001100=600）。
