曼昆经济学原理答案11—15章

曼昆《经济学原理（微观经济学分册）》（第6版）第11章公共物品和公共资源课后习题详解跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。

以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。

一、概念题1．排他性（excludability）答：排他性指一个人使用或消费一种产品或服务时可以阻止其他人使用或消费该种产品和服务的特性。

一种产品或服务具有排他性时，一个人使用或消费该产品或服务时可以阻止其他人使用或消费该种产品和服务。

排他性是区分公共物品和私人物品的标准之一。

生产者的排他原则有效时，生产者能够限制那些不为这种物品支付的消费者使用这种商品，消费者的排他性有效时，消费者在消费一种物品时，其他人能够被排除在外。

在排他性原则失效的地方，就会出现没有付出代价，却可以享受物品效用的“免费搭便车”现象。

2．消费中的竞争性（rivalry in consumption）答：消费中的竞争性指一种产品或服务被一个人消费从而减少了其他人消费的特性。

如果某人已经使用了某个商品（如某一火车座位），其他人就不能再同时使用该商品，则这种商品就具有消费中的竞争性。

市场机制只有在具备排他性和竞争性两个特点的私人物品的场合才真正起作用，才有效率。

3．私人物品（private goods）答：私人物品指既有排他性又有竞争性的物品，是供个人单独消费的物品。

私人物品是那种可得数量将随任何人对它的消费或使用的增加而减少的物品，它具有两个特征：第一是竞争性，如果某人已消费了某种商品，则其他人就不能再消费该商品；第二是排他性，对商品支付价格的人才能消费商品，其他人则不能。

4．公共物品（public goods）（西北大学2003研；北京师范大学2007研；华南理工大学2010研）答：公共物品与私人物品相对应，指既无排他性又无竞争性的物品。

曼昆《经济学原理（微观经济学分册）》（第6版）第11章公共物品和公共资源复习笔记跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。

以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。

一、不同类型的物品1．相关概念：（1）排他性：一种物品具有的可以阻止一个人使用该物品的特性。

（2）消费者的竞争性：一个人使用一种物品将减少其他人对该物品的使用的特性。

（3）私人物品（private goods）：消费中既有排他性又有竞争性的物品。

（4）公共资源：有竞争性但无排他性的物品。

（5）公共物品：既无排他性又无竞争性的物品。

（6）自然垄断：当一种物品在消费中有排他性但没有竞争性时，就是自然垄断的物品。

2．四种类型的物品根据物品的排他性和消费竞争性可以将物品分为四种类型，如图11-1所示。

物品在消费中有没有排他性或竞争性往往是一个程度问题，有时候界限模糊，难以区分。

图11-1 四种类型的物品二、公共物品1．搭便车者问题搭便车者：得到一种物品的利益但避开为此付费的人。

由于公共物品没有排他性，搭便车者问题的存在就使私人市场无法提供公共物品。

但是，政府可以潜在地解决这个问题。

如果政府确信一种公共物品的总利益大于成本，它就可以提供该公共物品，并用税收收入对其进行支付，从而可以使每个人的状况变好。

2．一些重要的公共物品考虑三种重要的公共物品：国防、基础研究、反贫困。

（1）国防国防既无排他性，也无竞争性。

国防是政府应该提供的公共物品。

（2）基础研究基础研究可以通过研究创造出知识。

知识可区分为一般性知识与特定知识：①特定技术知识可以申请专利，专利使发明者创造的知识具有了排他性，这将激励企业拿出资金用于新产品开发的研究中，以便获得专利并出售；②一般性知识是公共物品，既无排他性，也无竞争性，企业往往搭一般知识的便车，很少在上面投资。

第十一章公共物品和共有资源复习题1．解释一种物品有“排他性”的含义。

解释一种物品有“竞争性”的含义。

比萨饼有排他性吗?有竞争性吗?答：一种物品具有“排他性”是指可以阻止一个人使用一种物品时该物品的特性。

一种物品有竞争性是指一个人使用一种物品减少其他人使用该物品的特性。

比萨饼有排他性，只要不卖给某人比萨饼就可以阻止他使用。

比萨饼也有竞争性，一个人多吃一块比萨饼，会使其他人少享受一块。

2．给公共物品下定义并举出一个例子。

私人市场本身能提供这种物品吗?并解释之。

答：公共物品是既无排他性又无竞争性的物品，私人市场本身不能提供这种物品。

公共物品没有排他性，因此，无法对公共物品的使用者收费，在私人提供这种物品时就存在搭便车的激励，从而使私人提供者无利可图。

3．什么是公共物品的成本一收益分析?为什么它是重要的?进行这种分析困难吗?答：公共物品的成本一收益分析是提供一种公共物品的社会成本和社会收益比较的研究。

只有比较提供一种公共物品的成本与收益，政府才能决定是否值得提供这种公共物品。

公共物品的成本一收益分析是一项艰苦的工作。

因为所有的人都可以免费使用一种公共物品，没有判断这种公共物品价值的价格。

简单地问人们，他们对一种公共物品的评价是多少是不可靠的。

那些受益于该公共物品的人有夸大他们的利益的激励。

那些受害于该公共物品的人有夸大他们成本的激励。

4．给共有资源下定义并举出一个例子。

没有政府干预，人们使用这种物品会太多还是太少?为什么?答：共有资源是有竞争性但无排他性的物品。

没有政府干预，人们使用这种物品会太多。

因为不能向使用共有资源的人收费，而且，一个人对共有资源的使用会减少其他人的使用，所以，共有资源往往被过度使用。

问题与应用1．本书认为公共物品和共有资源都涉及外部性。

A．与公共物品相关的外部性一般是正的还是负的?用例子来回答。

自由市场的公共物品量一般是大于还是小于有效率的数量?答：与公共物品相关的外部性一般是负的。

曼昆《经济学原理（微观经济学分册）》（第6版）第11章公共物品和公共资源课后习题详解一、概念题1．排他性（excludability）答：排他性指一个人使用或消费一种产品或服务时可以阻止其他人使用或消费该种产品和服务的特性。

一种产品或服务具有排他性时，一个人使用或消费该产品或服务时可以阻止其他人使用或消费该种产品和服务。

排他性是区分公共物品和私人物品的标准之一。

生产者的排他原则有效时，生产者能够限制那些不为这种物品支付的消费者使用这种商品，消费者的排他性有效时，消费者在消费一种物品时，其他人能够被排除在外。

在排他性原则失效的地方，就会出现没有付出代价，却可以享受物品效用的“免费搭便车”现象。

2．消费中的竞争性（rivalry in consumption）答：消费中的竞争性指一种产品或服务被一个人消费从而减少了其他人消费的特性。

如果某人已经使用了某个商品（如某一火车座位），其他人就不能再同时使用该商品，则这种商品就具有消费中的竞争性。

市场机制只有在具备排他性和竞争性两个特点的私人物品的场合才真正起作用，才有效率。

3．私人物品（private goods）答：私人物品指既有排他性又有竞争性的物品，是供个人单独消费的物品。

私人物品是那种可得数量将随任何人对它的消费或使用的增加而减少的物品，它具有两个特征：第一是竞争性，如果某人已消费了某种商品，则其他人就不能再消费该商品；第二是排他性，对商品支付价格的人才能消费商品，其他人则不能。

4．公共物品（public goods）（西北大学2003研；北京师范大学2007研；华南理工大学2010研）答：公共物品与私人物品相对应，指既无排他性又无竞争性的物品。

一种公共物品可以同时供一个以上的人消费，任何一个人对某种公共物品的消费，都不排斥其他人对这种物品的消费，也不会减少其他人由此而获得的满足。

公共物品具有四个特性：①非排他性。

一种公共物品可以同时供一个以上的人消费，任何人对某种公共物品的消费，都不排斥其他人对这种物品的消费，也不会减少其他人由此而获得的满足。

曼昆《经济学原理》第七版课后习题的答案（中文版）！！练习题1、任何一个所得税表都体现了两种税率——平均税率和边际税率。

（题中的表见课本12章）a、平均税率定义为支付的总税收除以收入。

对表12—7中的比例税制来说，赚5万美元、10万美元和20万美元的人，其平均税率分别是多少？在累退税制和累进税制中相对应的平均税率是多少？答：从表12—7中很容易看出，赚5万美元、10万美元和20万美元的人，其平均税率都是25%。

在累退税制中，赚5万美元、10万美元和20万美元的人，其平均税率分别是30%，25%，20%。

在累进税制中，赚5万美元、10万美元和20万美元的人，其平均税率分别是20%，25%，30%。

b、边际税率定义为额外收入支付的税收除以增加的额外收入。

计算比例税制下，收入从5万美元增加到10万美元的边际税率。

计算收入从10万美元增加到20万美元的边际税率。

计算累退税制和累进税制下相对应的边际税率答：（1）比例税制。

当收入从5万美元增加到10万美元时，税收量增加了1.25万，因此边际税率为1.25/5=0.25，即25%。

当收入从10万美元增加到20万美元时，税收量增加了2.5万，因此边际税率为2.5/10=0.25，即25%。

（2）累退税制。

当收入从5万美元增加到10万美元时，税收量增加了1万，因此边际税率为1/5=0.2，即20%。

当收入从10万美元增加到20万美元时，税收量增加了1.5万，因此边际税率为1.5/10=0.15，即15%。

（3）累进税制。

当收入从5万美元增加到10万美元时，税收量增加了1.5万，因此边际税率为1.5/5=0.3，即30%。

当收入从10万美元增加到20万美元时，税收量增加了3.5万，因此边际税率为3.5/10=0.35，即35%。

c、描述这三种税制中每一种的平均税率和边际税率之间的关系。

一般来说，某人在决定是否接受工资比目前工作略高一点的工作时，哪一种税率更适用？在判断税制的纵向平等时，哪一种税率更适用？答：在比例税制下，平均税率和边际税率相等，且都不随收入变动而变动。

曼昆《经济学原理（微观经济学分册）》（第6版）第15章垄断复习笔记跨考网独家整理最全经济学考研真题，经济学考研课后习题解析资料库，您可以在这里查阅历年经济学考研真题，经济学考研课后习题，经济学考研参考书等内容，更有跨考考研历年辅导的经济学学哥学姐的经济学考研经验，从前辈中获得的经验对初学者来说是宝贵的财富，这或许能帮你少走弯路，躲开一些陷阱。

以下内容为跨考网独家整理，如您还需更多考研资料，可选择经济学一对一在线咨询进行咨询。

一、垄断产生的原因垄断企业是指一个没有相似替代品的产品的唯一卖者的企业。

垄断产生的基本原因是进入壁垒：垄断企业能在其市场上保持唯一卖者的地位，是因为其他企业不能进入市场并与之竞争。

进入壁垒有三个主要形成原因：第一，垄断资源：生产所需要的关键资源由单个企业所拥有；第二，政府管制：政府给予单个企业排他性地生产某种物品或劳务的权利；第三，生产流程：某个企业能以低于大量生产者的成本生产产品。

1．垄断资源垄断产生的最简单方法是单个企业拥有一种关键的资源。

垄断企业比竞争市场上任何一家企业有大得多的市场势力。

即使产品边际成本很低，垄断企业也可以利用市场势力也可以制定极高的价格。

虽然关键资源的排他性所有权是垄断的一个潜在起因，但实际上垄断很少产生于这种原因。

现实经济如此巨大，且资源由许多人拥有。

由于许多物品可以在国际上交易，它们的市场的自然范围往往很广泛。

因此，拥有没有相近替代品资源的企业的例子很少。

2．创造的垄断在许多情况下，垄断的产生是因为政府给予一个人或一个企业排他性地出售某种物品或劳务的权利，有时垄断产生于想成为垄断者的人的政治影响，还有些时候，政府也会出于公共利益而赋予某种垄断的权利。

专利法和版权法是两个重要的例子。

由于这些法律使一个生产者成为垄断者，所以也就使其价格高于竞争市场上的价格。

通过允许这些垄断生产者收取较高价格并赚取较多利润，这些法律也鼓励了一些合意的行为。

有关专利和版权的法律既有利益也有成本。

第十一章公共物品和共有资源复习题1．解释一种物品有“排他性”的含义。

解释一种物品有“竞争性”的含义。

比萨饼有排他性吗?有竞争性吗?答：一种物品具有“排他性”是指可以阻止一个人使用一种物品时该物品的特性。

一种物品有竞争性是指一个人使用一种物品减少其他人使用该物品的特性。

比萨饼有排他性，只要不卖给某人比萨饼就可以阻止他使用。

比萨饼也有竞争性，一个人多吃一块比萨饼，会使其他人少享受一块。

2．给公共物品下定义并举出一个例子。

私人市场本身能提供这种物品吗?并解释之。

答：公共物品是既无排他性又无竞争性的物品，私人市场本身不能提供这种物品。

公共物品没有排他性，因此，无法对公共物品的使用者收费，在私人提供这种物品时就存在搭便车的激励，从而使私人提供者无利可图。

3．什么是公共物品的成本一收益分析?为什么它是重要的?进行这种分析困难吗?答：公共物品的成本一收益分析是提供一种公共物品的社会成本和社会收益比较的研究。

只有比较提供一种公共物品的成本与收益，政府才能决定是否值得提供这种公共物品。

公共物品的成本一收益分析是一项艰苦的工作。

因为所有的人都可以免费使用一种公共物品，没有判断这种公共物品价值的价格。

简单地问人们，他们对一种公共物品的评价是多少是不可靠的。

那些受益于该公共物品的人有夸大他们的利益的激励。

那些受害于该公共物品的人有夸大他们成本的激励。

4．给共有资源下定义并举出一个例子。

没有政府干预，人们使用这种物品会太多还是太少?为什么?答：共有资源是有竞争性但无排他性的物品。

没有政府干预，人们使用这种物品会太多。

因为不能向使用共有资源的人收费，而且，一个人对共有资源的使用会减少其他人的使用，所以，共有资源往往被过度使用。

问题与应用1．本书认为公共物品和共有资源都涉及外部性。

A．与公共物品相关的外部性一般是正的还是负的?用例子来回答。

自由市场的公共物品量一般是大于还是小于有效率的数量?答：与公共物品相关的外部性一般是负的。

SOLUTIONS TO TEXT PROBLEMS:Quick Quizzes1. Public goods are goods that are neither excludable nor rival. Examples include national defense,knowledge, and uncongested nontoll roads. Common resources are goods that are rival but not excludable. Examples include fish in the ocean, the environment, and congested nontoll roads. 2. The free-rider problem occurs when people receive the benefits of a good but avoid paying for it.The free-rider problem induces the government to provide public goods because if the government uses tax revenue to provide the good, everyone pays for it and everyone enjoys its benefits. The government should decide whether to provide a public good by comparing the good’s costs to its benefits; if the benefits exceed the costs, society is better off.3. Governments try to limit the use of common resources because one person’s use of the resourcediminishes others’ use of it, so there is a negative externality which leads people to use common resources excessively.Questions for Review1. An excludable good is one that people can be prevented from using. A rival good is one for whichone person's use of it diminishes another person's enjoyment of it. Pizza is both excludable, sincea pizza producer can prevent someone from ea ting it who doesn't pay for it, and rival, since whenone person eats it, no one else can eat it.2. A public good is a good that is neither excludable nor rival. An example is national defense, whichprotects the entire nation. No one can be prevented from enjoying the benefits of it, so it is not excludable, and an additional person who benefits from it does not diminish the value of it to others, so it is not rival. The private market will not supply the good, since no one would pay for itbecause they cannot be excluded from enjoying it if they don't pay for it.3. Cost-benefit analysis is a study that compares the costs and benefits to society of providing a publicgood. It is important because the government needs to know which public goods people value most highly and which have benefits that exceed the costs of supplying them. It is hard to dobecause quantifying the benefits is difficult to do from a questionnaire and because respondents have little incentive to tell the truth.4. A common resource is a good that is rival but not excludable. An example is fish in the ocean. Ifsomeone catches a fish, that leaves fewer fish for everyone else, so it's a rival good. But theocean is so vast, you cannot charge people for the right to fish, or prevent them from fishing, so it is not excludable. Thus, without government intervention, people will use the good too much,since they don't account for the costs they impose on others when they use the good.Problems and Applicat ions1. a. The externalities associated with public goods are positive. Since the benefits from thepublic good received by one person don't reduce the benefits received by anyone else, thesocial value of public goods is substantially greater than the private value. Examplesinclude national defense, knowledge, uncongested non-toll roads, and uncongested parks.Since public goods aren't excludable, the free-market quantity is zero, so it is less than the215efficient quantity.b. The externalities associated with common resources are generally negative. Sincecommon resources are rival but not excludable (so not priced) the use of the commonresources by one person reduces the amount available for others. Since commonresources are not priced, people tend to overuse them their private cost of using theresources is less than the social cost. Examples include fish in the ocean, theenvironment, congested non-toll roads, the Town Commons, and congested parks.2. a. (1) Police protection is a natural monopoly, since it is excludable (the police may ignoresome neighborhoods) and not rival (unless the police force is overworked, they're availablewhenever a crime arises). You could make an argument that police protection is rival, ifthe police are too busy to respond to all crimes, so that one person's use of the policereduces the amount available for others; in that case, police protection is a private good.(2) Snow plowing is most likely a common resource. Once a street is plowed, it isn'texcludable. But it is rival, especially right after a big snowfall, since plowing one streetmeans not plowing another street.(3) Education is a private good (with a positive externality). It is excludable, sincesomeone who doesn't pay can be prevented from taking classes. It is rival, since thepresence of an additional student in a class reduces the benefits to others.(4) Rural roads are public goods. They aren't excludable and they aren't rival sincethey're uncongested.(5) City streets are common resources when congested. They aren't excludable, sinceanyone can drive on them. But they are rival, since congestion means every additionaldriver slows down the progress of other drivers. When they aren't congested, city streetsare public goods, since they're no longer rival.b. The government may provide goods that aren't public goods, such as education, becauseof the externalities associated with them.3. a. Charlie is a free rider.b. The government could solve the problem by sponsoring the show and paying for it with taxrevenue collected from everyone.c. The private market could also solve the problem by making people watch commercials thatare incorporated into the program. The existence of cable TV makes the good excludable,so it would no longer be a public good.4. a. Since knowledge is a public good, the benefits of basic scientific research are available tomany people. The private firm doesn't take this into account when choosing how muchresearch to undertake; it only takes into account what it will earn.b. The United States has tried to give private firms incentives to provide basic research bysubsidizing it through organizations like the National Institute of Health and the NationalScience Foundation.c. If it's basic research that adds to knowledge, it isn't excludable at all, unless people in othercountries can be prevented somehow from sharing that knowledge. So perhaps U.S.firms get a slight advantage because they hear about technological advances first, butknowledge tends to diffuse rapidly.5. When a person litters along a highway, others bear the negative externality, so the private costsare low. Littering in your own yard imposes costs on you, so it has a higher private cost and is thus rare.6. When the system is congested, each additional rider imposes costs on other riders. For example,when all seats are taken, some people must stand. Or if there isn't any room to stand, somepeople must wait for a train that isn't as crowded. Increasing the fare during rush hourinternalizes this externality.7. On privately owned land, the amount of logging is likely to be efficient. Loggers have incentives todo the right amount of logging, since they care that the trees replenish themselves and the forest can be logged in the future. Publicly owned land, however, is a common resource, and is likely to be overlogged, since loggers won't worry about the future value of the land.Since public lands tend to be overlogged, the government can improve things by restricting thequantity of logging to its efficient level. Selling permits to log, or taxing logging, could be used to reach the appropriate quantity by internalizing the externality. Such restrictions are unnecessary on privately owned lands, since there is no externality.8. a. Overfishing is rational for fishermen since they're using a common resource. They don'tbear the costs of reducing the number of fish available to others, so it's rational for them tooverfish. The free-market quantity of fishing exceeds the efficient amount.b. A solution to the problem could come from regulating the amount of fishing, taxing fishingto internalize the externality, or auctioning off fishing permits. But these solutionswouldn't be easy to implement, since many nations have access to ocea ns, so internationalcooperation would be necessary, and enforcement would be difficult, because the sea is solarge that it is hard to police.c. By giving property rights to countries, the scope of the problem is reduced, since eachcountry has a greater incentive to find a solution. Each country can impose a tax or issuepermits, and monitor a smaller area for compliance.d. Since government agencies (like the Coast Guard in the United States) protect fishermenand rescue them when they need help, the fishermen aren't bearing the full costs of theirfishing. Thus they fish more than they should.e. The statement, "Only when fishermen believe they are assured a long-term and exclusiveright to a fishery are they likely to manage it in the same far-sighted way as good farmersmanage they land," is sensible. If fishermen owned the fishery, they would be sure not tooverfish, because they would bear the costs of overfishing. This is a case in whichproperty rights help prevent the overuse of a common resource.f. Alternatives include regulating the amount of fishing, taxing fishermen, auctioning offfishing permits, or taxing fish sold in stores. All would tend to reduce the amount offishing from the free-market amount toward the efficient amount.9. The private market provides information about the quality or function of goods and services inseveral different ways. First, producers advertise, providing people information about the product and its quality. Second, private firms provide information to consumers with independent reportson quality; an example is the magazine Consumer Reports. The government plays a role as well, by regulating advertising, thus preventing firms from exaggerating claims about their products,regulating certain goods like gasoline and food to be sure they are measured properly and provided without disease, and not allowing dangerous products on the market.10. To be a public good, a good must be neither rival nor excludable. When the Internet isn’tcongested, it is n ot rival, since one person’s use of it does not affect anyone else. However, at times traffic on the Internet is so great that everything slows down at such times, the Internet is rival. Is the Internet excludable? Since anyone operating a Web site can charge a customer for visiting the site by requiring a password, the Internet is excludable. Thus the Internet is notstrictly a public good. Since the Internet is usually not rival, it is more like a natural monopolythan a public good. However, since most people’s Web sites contain information and exclude no one, the majority of the Internet is a public good (when it is not congested).11. Recognizing that there are opportunity costs that are relevant for cost-benefit analysis is the key toanswering this question. A richer community can afford to place a higher value on life and safety.So the richer community is willing to pay more for a traffic light, and that should be considered in cost-benefit analysis.。