微观经济学-EXTERNALITIESAND
范里安微观经济学外部效应Externalities
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外部效应与财产权利
抽烟 p(sB) 抽烟
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建议一个减少 1 抽烟的权利交 易市场导致了 sB 一个有效分配。
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外部效应与财产权利
注意
– 得到产权的一方比在没有得到产权时 的最偏好分配时的状况好。 – 均衡时的抽烟量取决于哪一方拥有产 权。
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无效率与负外部效应
有效率的抽烟与钱的分配为什么？
无效率与负外部效应
抽烟 抽烟
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1
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mB
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无效率与负外部效应
抽烟 抽烟
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1
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无效率与负外部效应
抽烟 抽烟
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无效率与负外部效应
抽烟 抽烟
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B
外部效应与财产权利
抽烟 抽烟
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1
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外部效应与财产权利
抽烟 抽烟
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外部效应与财产权利
抽烟 p(sB) 抽烟
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sB
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外部效应与财产权利
抽烟 p(sB) 抽烟
微观经济学(8)外部性
2. ...它与需求曲线 共同决定了污染量
2. ...它与需求 曲线一起决定了 污染的价格
1. 污染许可证 确定了污染量
外部性的私人解决方法 Private Solutions to Externalities
并不总是需要政府行为来解决外部 性问题。 Government action is not always needed to solve the problem of externalities.
禁止某些行为
通常采取管制的形式:
Forbid certain behaviors. 要求某些行为 Require certain behaviors.
例子
要求所有的学生注射疫苗 禁止排放废水、废气
以市场为基础的政策
Market-Based Policies
政府通过税收和补贴，使私人激励与社会效率 一致。 而征收的税。
的产量比社会希望的要少。
外部性的内在化 Internalizing Externalities
税收是用来把负外部性内在化的主要工
具。 Taxes are the primary tools used to internalize negative externalities. 补贴是用来把正外部性内在化的主要工 具。 Subsidies are the primary tools used to internalize positive externalities.
铝市场和福利经济学 The Market for Aluminum and Welfare Economics
对于生产的每一单位铝而言，社会成本包
括生产者的私人成本，加上受到污染不利 影响的旁观者的成本。 For each unit of aluminum produced, the social cost includes the private costs of the producers plus the cost to those bystanders adversely affected by the pollution.
微观经济教材之外部效应培训讲义
Money is a good and smoke is a bad for Agent B.
Smoke
1
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mB
Allocations
Improved driving habits that reduce accident risks.
Education.
Externalities and Efficiency
Crucially, an externality impacts a third party; i.e. somebody who is not a participant in the activity that produces the external cost or benefit.
An externality is a cost or a benefit imposed upon someone by actions taken by others. The cost or benefit is thus generated externally to that somebody.
Examples of Positive Externalities
A well-maintained property next door that raises the market value of your property.
A pleasant cologne or scent worn by the person seated next to you.
Externalities and Efficiency
Externalities cause Pareto inefficiency; typically – too much scarce resource is allocated to an activity which causes a negative externality – too little resource is allocated to an activity which causes a positive externality.
微观经济学教学课件：Ch15-Externalities
Greener and Smarter
Environmental issues are at the same time everybody’s problem and nobody’s problem. Human beings are learning more and more every day. But are we learning more at a fast enough pace? How can we ensure that we use resources efficiently in the face of externalities?
Externalities in Our Lives
Positive Consumption Externalities பைடு நூலகம்ositive consumption externalities are also common. When you get a flue vaccination, everyone you come into contact with benefits. When the owner of an historic building restores it, everyone who sees the building gets pleasure.
Negative Externalities: Pollution
Production and Pollution: How Much? In the market for a good with an externality that is unregulated, the amount of pollution created depends on the equilibrium quantity of the good produced.
Chap10Externalities曼昆经济学原理,微观英文版
Chap10Externalities曼昆经济学原理,微 观英文版
Recall that: Adam Smith’s “invisible hand” of the marketplace leads selfinterested buyers and sellers in a market to maximize the total benefit that society can derive from a market.
Chap10Externalities曼 昆经济学原理,微观英文 版
Chapter 10
Copyright © 2001 by Harcourt, Inc. All rights reserved. Requests for permission to make copies of any part of the
work should be mailed to: Permissions Department, Harcourt College Publishers, Harcourt, Inc. items and derived items copyright © 2001 by Harc6o2u7rt7, ISnce.a Harbor Drive, Orlando, Florida 32887-6777.
Harcourt, Inc. items and derived items copyright © 2001 by Harcourt, Inc.
Chap10Externalities曼昆经济学 原理,微观英文版
Automobile exhaust Cigarette smoking Barking dogs (loud pets) Loud stereos in an apartment building
微观经济学(第十四讲)
Externalities and Property Rights
Smoke Smoke
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Externalities and Property Rights
Smoke Smoke
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Externalities and Property Rights
公地悲剧
考虑一个由整个村庄拥有的公共放牧区 村民在牧区里放牛. 牛奶的产量为 f(c), 其中c表示牧牛的数量， 并且 f’>0 and f”<0. 村民应该选择放多少的牛以最大化自身的收益?
The Tragedy of the Commons
Milk
f(c)
c
The Tragedy of the Commons
生活中的例子（正的外部性）
一个喷洒了古龙水或令人愉悦香水的人坐在 你旁边. 驾驶习惯的改善使得交通事故的发生机率降 低. 养蜂场与果园.
Inefficiency & Negative Externalities
设想同房间的两个人A and B, 及两个物 品“货币”和“抽烟”. 对A来说，“货币”和“抽烟”均带来正 的效应 对B来说，“货币”带来正的效应，“抽 烟”具有负的效应.
1
货币和香烟都对代理人A 产生正的效用.
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Inefficiency & Negative Externalities
微观经济学(第九版)课件：外部性和公共物品
•当二氧化硫和氧化氮在大气中产生反应后，便会产生各种
酸性的混合物，即酸雨。
• 酸雨可以对人的健康产生直接的影响，要么通过大气，
要么通过土壤影响粮食的生产。
•酸雨除了对人体健康产生影响外，还能对水、森林和
人造的建筑产生影响。
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EXAMPLE 18.1
•有效产出Q*要比它低，由需求和边际社会成本MSCI的交点决定。
社会总损失就是图中MSCI、D和产出Q1之间的阴影三角形面积
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正的外部性和无效率
● 边际外部收益 企业增加一单位产出给其他个人或群体带来的收益增加
● 边际社会收益 边际私人收益和边际外部收益之和
当存在正的外部性时，边际社会收益
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EXAMPLE 18.3
排污权交易和清洁空气
•由于它们的有限性，泡沫计划和抵消计划大大低估了一个有广泛基础的排
污权交易制度的收益。
•在一项研究中，有三种让美国所有的杜邦工厂的烃排放减少85%的成
本的政策：
•(1)每家工厂的每个排放源都必须减少85%；
•(2)每家工厂必须将其总的排放减少85%，费
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排污标准与排污费的比较
在信息有限的时候，决策可能
面临对所有厂商或者单用排污
费，或者单用排污标准的选择。
收取3美元排污费实现的14单
位排污水平比每家厂商7单位
的排污标准要便宜得多。在使
用排污费时，减污成本曲线较
低的厂商(厂商2)比成本曲线
较高的厂商(厂商1)所减少的
效的。
•可交易许可证同样有效
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EXAMPLE 18.3
微观经济学外部性和公共物品
Chapter 20第二十章EXTERNALITIES ANDPUBLIC GOODS外部性和公共物品Copyright ©2005 by South-Western, a division of Thomson Learning. All rights reserved.Externality外部性•An externality occurs whenever the activities of one economic agent affect the activities of another economic agent in ways that are not reflected in market transactions 当一个经济参加者的行为以并不反映在市场交易中的形式影响其他经济参加者的行为时，会产生外部性–chemical manufacturers releasing toxic fumes 化学品制造厂释放有毒烟雾–noise from airplanes飞机的噪音–motorists littering roadways 道路上驾驶员乱丢垃圾Interfirm Externalities企业间的外部性•Consider two firms, one producing good x and the other producing good y 考虑两个企业，一个生产商品x，另一个生产商品y•The production of x will have an external effect on the production of y if the output of y depends not only on thelevel of inputs chosen by the firm but on the level at which x is produced如果y的产出不仅仅依赖于该企业选择的投入，还依赖于x的生产水平，商品x的生产对商品y的生产就有外部影响，y = f(k,l;x)Beneficial Externalities正外部性•The relationship between the two firms can be beneficial两个企业间的关系可能是有益的–two firms, one producing honey and the otherproducing apples 两个企业，一个生产蜂蜜，另一个生产苹果Externalities in Utility效用的外部性•Externalities can also occur if the activities of an economicagent directly affect an individual’s utility如果一个经济体的行为能直接影响一个人的效用，也会发生外部性–externalities can decrease or increase utility 外部性可以减少或者增加效用•It is also possible for someone’s utility to be dependent on the utility of another 也可能是某人的效用依赖于其他人的效用utility = U S(x1,…,x n;U J)Public Goods Externalities公共品外部性•Public goods are nonexclusive 公共品是非排他的–once they are produced, they provide benefits to an entire group一旦生产了，他们就会使整个群体受益–it is impossible to restrict these benefits to the specificgroups of individuals who pay for them 不可能将这些收益限制在付了钱的的特定群体内Externalities and Allocative Inefficiency 外部性和分配的非有效性•Externalities lead to inefficient allocations of resources because market prices do not accurately reflect theadditional costs imposed on or the benefits provided tothird parties 外部性将导致资源的非有效分配，因为市场价格并不准确地反映第三方的额外成本或者收益•We can show this by using a general equilibrium model with only one individual 我们可以使用仅有一个人的一般均衡模型说明这一结论Externalities and Allocative Inefficiency 外部性和分配的非有效性•Suppose that the individual’s utility function is given by 假设个人的效用函数是utility = U(x c,y c)where x c and y c are the levels of x and y consumed等式中，xc 和yc是对商品x和y的消费水平•The individual has initial stocks of x* and y* 个人有x*和y*的初始存量–can consume them or use them in production 可以消费或者在生产中使用Externalities and Allocative Inefficiency 外部性和分配的非有效性•Assume that good x is produced using only good y according to假设商品x仅使用商品y进行生产，按照x o= f(y i)•Assume that the output of good y depends on both the amount of x used in the production process and theamount of x produced假设商品y的产出依赖于生产中使用的x的数量以及生产出的x的数量y o= g(x i,x o)Externalities and Allocative Inefficiency 外部性和分配的非有效性•For example, y could be produced downriver from x and thus firm y must cope with any pollution that production of x creates比如，y可以在x的下游生产，所以企业y必须处理生产x产生的任何污染•This implies that g1> 0 and g2< 0 这意味着，g1> 0 and g2 < 0Externalities and Allocative Inefficiency 外部性和分配的非有效性•The quantities of each good in this economy areconstrained by the initial stocks available and by theadditional production that takes place 经济中，每一种商品的数量都受到可获得的初始存量以及额外生产的约束x c+ x i= x o+ x*y c+ y i= y o+ y*Finding the Efficient Allocation寻找有效分配•The economic problem is to maximize utility subject to the four constraints listed earlier 经济问题是在之前列出的四个约束条件下，达到效用最大化•The Lagrangian for this problem is 这个问题的拉格朗日函数为L= U(x c,y c) + λ1[f(y i) -x o] + λ2[g(x i,x o) -y o] + λ3(x c+ x i-x o-x*)+ λ4(y c+ y i-y o-y*)Finding the Efficient Allocation寻找有效分配•The six first-order conditions are 六个一阶条件为∂L/∂x c= U1+ λ3= 0 （1）∂L/∂y c= U2+ λ4= 0 （2）∂L/∂x i= λ2g1+ λ3= 0 （3）∂L/∂y i= λ1f y+ λ4= 0 （4）∂L/∂x o= -λ1+λ2g2-λ3= 0 （5）∂L/∂y o= -λ2-λ4= 0 （6）Finding the Efficient Allocation寻找有效分配•Taking the ratio of the first two, we find 由前两个等式的比值得MRS = U1/U2= λ3/λ4•The third and sixth equation also imply that 第三个和第六个等式也意味着MRS = λ3/λ4= λ2g1/λ2= g1•Optimality in y production requires that the individual’s MRS in consumption equals the marginal productivity of x in the production of y 最优化生产y ，要求个人消费中的MRS等于y的生产中x的边际生产率Finding the Efficient Allocation寻找有效分配•To achieve efficiency in x production, we must also consider the externality this production poses to y为了在x的生产中达到有效性，我们也必须考虑这一生产对y的外部性•Combining the last three equations gives 将最后三个等式结合起来得MRS = λ3/λ4= (-λ1+ λ2g2)/λ4= -λ1/λ4+ λ2g2/λ4MRS = 1/f y-g2Finding the Efficient Allocation寻找有效分配•This equation requires the individual’s MRS to equal dy/dx obtained through x production这个等式要求个人的MRS等于从x生产中获得的dy/dx –1/f y represents the reciprocal of the marginal productivity of y in x production 1/f y代表x生产中，y的边际生产率的倒数–g2represents the negative impact that added x production has on y output g2代表增加x的生产对y的产出的负面影响•allows us to consider the externality from x production 这允许我们考虑来自x生产的外部性Inefficiency of the Competitive Allocation 竞争性分配的非有效性•Reliance on competitive pricing will result in an inefficient allocation of resources 竞争性定价的结果将导致资源的非有效分配• A utility-maximizing individual will opt for 效用最大化的个人将选择MRS = P x/P yand the profit-maximizing producer of y would choose x inputaccording to且y的利润最大化生产者将选择投入x ，根据P x= P y g1Inefficiency of the Competitive Allocation 竞争性分配的非有效性•But the producer of x would choose y input so that 但是x的生产者将选择投入y使得P y= P x f yP x/P y= 1/f y•This means that the producer of x would disregard the externality that its production poses for y and willoverproduce x这意味着，x的生产者将无视它的生产对y的外部性并且会过多生产xProduction Externalities生产外部性•Suppose that two newsprint producers are located along a river 假设两个新闻用纸制造者位于河边•The upstream firm has a production function of the form上游企业的生产函数为x= 2,000l x0.5Production Externalities生产外部性•The downstream firm has a similar production function but its output may be affected by chemicals that firm xpours in the river下游企业有着相似的生产函数，但是其产出受到企业x倒入河流的化学品的影响y= 2,000l y0.5(x -x0)α(for x> x0)y= 2,000l y0.5(for x ≤x0)where x0represents the river’s natural capacity forpollutants等式中，x0代表河流对于污染物的自然承载力Production Externalities生产外部性•When firm x does have a negative externality (α< 0), its profit-maximizing decision will be unaffected (l x* = 400 and x*= 40,000) 当企业x确实有负外部性时(α< 0)，企业x的利润最大化决策将不受影响(l x* = 400 且x*=40,000)•But the marginal product of labor will be lower in firm y because of the externality 但是，在企业y中，由于外部性，劳动的边际产品将较低Production Externalities生产外部性•Suppose that these two firms merge and the manager must now decide how to allocate the combined workforce 假设这两个企业合并，管理者现在必须决定如何分配劳动力•If one worker is transferred from x to y, output of x becomes 如果一名工人从x转移到y，x的产出变为x = 2,000(399)0.5= 39,950 (减少了50）and output of y becomes而y的产出变为y = 2,000(88)0.5(1,950)-0.1= 8,796 （增加了73）Production Externalities生产外部性•Total output increased by 23 with no change in total labor input总劳动投入没有变化，而总产出增加了23•The earlier market-based allocation was inefficient because firm x did not take into account the effect of its hiring decisions on firm y 之前基于市场的分配是无效率的，因为企业x 并没有考虑到其雇用策略对企业y的影响Production Externalities生产外部性•If firm x was to hire one more worker, its own output wouldrise to如果企业x多雇佣一名工人，其产出将增加至x= 2,000(401)0.5= 40,050 （增加了50）–the private marginal value product of the 401st worker is equal to the wage第401名工人的私人边际价值产品等于工资•But, increasing the output of x causes the output of y to fall (by about 21 units) 但是，增加x的产出，导致y的产出下降（21个单位）•The social marginal value product of the additional worker is only $29额外一名工人的社会边际价值产品仅为$29Solutions to the Externality Problem 外部性问题的解决方法•The output of the externality-producing activity is too high under a market-determined equilibrium 在市场决定的均衡下，具有外部性的生产活动的产出过高了•Incentive-based solutions to the externality problem originated with Pigou, who suggested that the most direct solution would be to tax the externality-creating entity外部性问题的基于激励的解决办法起源于庇古，他提出，最直接的解决方法是对产生外部性的实体征税Solutions to the Externality Problem 外部性问题的解决方法Quantity of x PriceS = MC Dx 1p 1Market equilibrium will occur at p 1, x 1市场均衡为p 1, x 1If there are external costs in the production of, social marginal costs are represented by MC’如果在x 生产中存在外部成本，社会边际成本将由MC’表示MC’Solutions to the Externality Problem 外部性问题的解决方法Quantity of x PriceS = MC MC’Dx 2tax A tax equal to these additional marginal costs will reduce output to the socially optimal level (x 2)等于额外边际成本的税收将减少产出至社会最优水平(x 2)p 2The price paid for the good (p 2) nowreflects all costs商品的价格(p 2)现在反映了所有的成本A Pigouvian Tax on Newsprint对新闻纸的庇古税• A suitably chosen tax on firm x can cause it to reduce its hiring to a level at which the externality vanishes对企业x选择合适地征税，会使其减少其雇佣水平至外部性消失的水平•Because the river can handle pollutants with an output of x= 38,000, we might consider a tax that encourages the firm to produce at that level 因为河流可以处理产出水平x= 38,000的污染物，我们可以考虑税收，鼓励企业在该水平生产A Pigouvian Tax on Newsprint对新闻纸的庇古税•Output of x will be 38,000 if l x= 361如果l x= 361，产出x 将为38,000，•Thus, we can calculate t from the labor demand condition 所以，我们从劳动需求条件计算得t(1 -t)MP l= (1 -t)1,000(361)-0.5= 50t = 0.05•Therefore, a 5 percent tax on the price firm x receives would eliminate the externality 所以，对企业x征收价格百分之五的税收可以消除外部性Taxation in the General Equilibrium Model 一般均衡模型下的税收•The optimal Pigouvian tax in our general equilibrium model is to set t= -p y g2 在我们的一般均衡模型下，最g2优的庇古税是，t= -py–the per-unit tax on x should reflect the marginal harm that x does in reducing y output, valued at the price of good y 对x的单位税收，应该反映x减少y产出的边际损害，以商品y的价格衡量Taxation in the General Equilibrium Model 一般均衡模型下的税收•With the optimal tax, firm x now faces a net price of (p x-t) and will choose y input according to 对于最优税收，企业x现在面临净价格(p x-t)，会选择投入y，根据p y= (p x-t)f y•The resulting allocation of resources will achieve 最终的资源分配将达到MRS = p x/p y= (1/f y) + t/p y= (1/f y) -g2Taxation in the General Equilibrium Model 一般均衡模型下的税收•The Pigouvian tax scheme requires that regulators have enough information to set the tax properly庇古税模式要求管理者有足够的信息来确定合适的税收–in this case, they would need to know firm y’sproduction function 在这种情况下，他们需要知道企业y的生产函数Pollution Rights污染权利•An innovation that would mitigate the informational requirements involved with Pigouvian taxation is thecreation of a market for “pollution rights” 一个可以减轻对庇古税的信息要求的创新是创造一个“污染权利”市场•Suppose that firm x must purchase from firm y the rights to pollute the river they share 假设企业x必须从企业y购买他们共享河流的污染权–x’s choice to purchase these rights is identical to its output choice x对这些权利购买的选择等同于其产量选择Pollution Rights污染权利•The net revenue that x receives per unit is given by p x-r, where r is the payment the firm must make to firm y for each unit of x it produces x的每单位的净利润是p x-r，r 为每生产一单位x时企业必须支付给企业y的数量•Firm y must decide how many rights to sell firm x by choosing x output to maximize its profits通过选择x的产量来最大化自己的利润，企业y必须决定卖给企业x多少权利πy= p y g(x i,x o) + rx oPollution Rights污染权利•The first-order condition for a maximum is最大值的一阶条件是∂πy/∂x o= p y g2+ r = 0r= -p y g2•The equilibrium solution is identical to that for the Pigouvian tax均衡解与庇古税的相同–from firm x’s point of view, it makes no difference whether it pays the fee to the government or to firm y 从企业x的角度看，支付给政府或者企业y没有区别The Coase Theorem 科斯定理•The key feature of the pollution rights equilibrium is that the rights are well-defined and tradable with zerotransactions costs 污染权均衡的关键特征是，权利是完全定义的，并且可以按零交易成本进行交换•The initial assignment of rights is irrelevant 初始的权利配给无关–subsequent trading will always achieve the same, efficient equilibrium随后的交易总会达到相同的、有效率的均衡The Coase Theorem科斯定理•Suppose that firm x is initially given x T rights to produce (and to pollute) 假设企业x最初有x T权利进行生产（并且污染）–it can choose to use these for its own production or it may sell some to firm y 它可以将这些权利用于自己生产或者卖给企业y •Profits for firm x are given by 企业x的利润为πx= p x x o+ r(x T-x o) = (p x-r)x o+ rx Tπx= (p x-r)f(y i) + rx TThe Coase Theorem 科斯定理•Profits for firm y are given by 企业y的利润为πy= p y g(x i,x o) -r(x T-x o)•Profit maximization in this case will lead to precisely the same solution as in the case where firm y was assigned the rights 这种情况下的利润最大化，将与企业y得到权利的情况完全相同The Coase Theorem科斯定理•The independence of initial rights assignment is usually referred to as the Coase Theorem初始权利给定的无关性，常常被称为科斯定理–in the absence of impediments to making bargains, allmutually beneficial transactions will be completed没有议价阻碍时，所有共赢的交易都将得以进行–if transactions costs are involved or if information isasymmetric, initial rights assignments will matter如果存在交易成本或者信息不对称，初始权利分配将有关系Attributes of Public Goods公共品的属性• A good is exclusive if it is relatively easy to exclude individuals from benefiting from the good once it is produced如果一个商品生产出来后可以很容易地阻止个人从商品中受益，那么该商品是排他性的，• A good is nonexclusive if it is impossible, or very costly, to exclude individuals from benefiting from the good如果不能排除个人从商品中受益或者这样做的成本非常高，那么该商品是非排他性的Attributes of Public Goods公共品的属性• A good is nonrival if consumption of additional units of the good involves zero social marginal costs of production如果消费额外一单位商品所涉及的社会边际生产成本为零，那么该商品是非竞争性的，Public Good公共品• A good is a pure public good if, once produced, no one can be excluded from benefiting from its availability and if the good is nonrival --the marginal cost of an additional consumer is zero如果一个商品一旦生产出来，不能排除任何人从它的使用中获利，并且该商品是非竞争性的——增加一个消费者的边际成本是零，那么该商品是纯公共品Public Goods and Resource Allocation公共品和资源配置•We will use a simple general equilibrium model with two individuals (A and B) 我们将使用一个包含两个人（A和B）的简单的一般均衡模型•There are only two goods 只有两种商品–good y is an ordinary private good Y商品是普通私人商品•each person begins with an allocation (y A*and y B*) 每个人会有一定的初始分配(y A*和y B*)–good x is a public good that is produced using y 商品x是用商品y 生产的公共品x = f(y s A+ y s B)Public Goods and Resource Allocation公共品和资源配置•Resulting utilities for these individuals are 个人产生的效用如下U A[x,(y A*-y s A)]U B[x,(y B*-y s B)]•The level of x enters identically into each person’s utility curve x的水平影响每个人的效用曲线–it is nonexclusive and nonrival它是非排他的和非竞争的•each person’s consumption is unrelated to what he contributesto production每个人的消费与他对生产的贡献无关•each consumes the total amount produced每个人消费掉所有生产出来的量Public Goods and Resource Allocation公共品和资源配置•The necessary conditions for efficient resource allocation consist of choosing the levels of y s A and y s B that maximizeone person’s (A’s) utility for any given level of the other’s (B’s) utility 有效资源配置需要的情况包括选择这样的y s A和y s B，以使得在任何给定的另一个人(B的)的效用下，最大化这个人(A的)的效用•The Lagrangian expression is 拉格朗日表达式如下L= U A(x, y A*-y s A) + λ[U B(x, y B*-y s B) -K]Public Goods and Resource Allocation公共品和资源配置•The first-order conditions for a maximum are 最大化的一阶条件∂L/∂y s A= U1A f’ -U2A+ λU1B f’ = 0∂L/∂y s B= U1A f’ -λU2B+ λU1B f’ = 0•Comparing the two equations, we find比较这两个等式，我们发现λU2B= U2APublic Goods and Resource Allocation公共品和资源配置•We can now derive the optimality condition for the production of x 我们现在可以推导出x的最优生产水平•From the initial first-order condition we know that 对于最初的一阶条件我们知道U1A/U2A+ λU1B/λU2B= 1/f’MRS A+ MRS B= 1/f’•The MRS must reflect all consumers because all will get the same benefits MRS必须反映所有消费者，因为所有人得到相同的利益。
微观经济之外部效应培训讲义
u An externally imposed cost is a negative externality.
Examples of Negative Externalities
u Air pollution. u Water pollution. u Loud parties next door. u Traffic congestion. u Second-hand cigarette smoke.
Externalities and Property Rights
u Neither Agent A nor Agent B owns the air in their room.
u What happens if this property right is created and is assigned to one of them?
Externalities and Property Rights
u Causing a producer of an externality to bear the full external cost or to enjoy the full external benefit is called internalizing the externality(外 部效应内部化).
Smoke
Smoke
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中级微观经济-Chapter34_Externalities
外部效应
消费外部性：一个消费者的消费直接影 响到另一个人的行为。
例如：凌晨三点的音乐，饭店里吸烟的 邻座；邻居的花园
生产外部效应：一个厂商的生产可能性 受到另一个厂商或消费者的影响。
例如： 苹果园和养蜂场
外部效应
外部效应是指由其他人带来的成本或者 收益。这种成本或者收益是由其他人的 行为造成的。 带来收益的外部效应为正外部效应。 带来成本的外部效应为负外部效应。
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外部效应与财产权利
抽烟
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p(sA)
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ቤተ መጻሕፍቲ ባይዱ
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外部效应与财产权利
抽烟
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抽烟
1 两个人都福利
都得到改善， 并且有抽烟量 水平为正。 sA
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外部效应与财产权利
抽烟
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建立一个交易
1 抽烟权利的市
(c) f (c) pcc
村庄面对的问题为：
max (c) f (c) pcc.
c0
公共品悲剧
max (c) f (c) pcc.
c0
收入最大化的牛群放牧量c*满足：
f (c) pc
也即放牧牛的边际收益必须与 放牧牛的边际成本相等。
公共品悲剧
当 c = c*时,放牧每头牛的收益为：
生产外部效应
max s (s, x) pss cs (s, x).
公共经济学专业英语词汇整理
公共经济学专业英语词汇整理本文档旨在整理公共经济学专业相关的英语词汇，帮助研究者扩大词汇量并提高专业英语能力。
1. 宏观经济学（Macroeconomics）- Aggregate demand: 总需求- Aggregate supply: 总供给- Business cycle: 商业周期- Economic growth: 经济增长- Fiscal policy: 财政政策- Inflation: 通货膨胀- Monetary policy: 货币政策- Unemployment rate: 失业率2. 微观经济学（Microeconomics）- Demand: 需求- Supply: 供给- Market equilibrium: 市场均衡- Price elasticity: 价格弹性- Consumer surplus: 消费者剩余- Producer surplus: 生产者剩余- Monopoly: 垄断3. 经济学方法与理论（Economic Methods and Theories）- Cost-benefit analysis: 成本效益分析- Game theory: 博弈论- Rational choice theory: 理性选择理论- Supply and demand model: 供需模型- Economies of scale: 规模经济- Externalities: 外部性- Opportunity cost: 机会成本- Production possibility frontier: 生产可能性边界4. 公共财政（Public Finance）- Government budget: 政府预算- Taxation: 税收- Public debt: 公共债务- Tax incidence: 税负分担- Public goods: 公共产品- External debt: 外债- Tax evasion: 逃税- Revenue: 收入5. 发展经济学（Development Economics）- Poverty alleviation: 扶贫- Sustainable development: 可持续发展- Foreign direct investment: 外商直接投资- Human capital: 人力资本- Microfinance: 小额信贷- Economic inequality: 经济不平等- Millennium Development Goals: 千年发展目标以上仅为公共经济学专业部分相关英语词汇的简要整理。
中级微观经济学-Ch32 Externality
0 OB
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Inefficiency & Negative Externalities
Money is a good and smoke is a bad for Agent B.
Smoke
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Smoke
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Money and smoke are both goods for Agent A.
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Inefficiency & Negative Externalities
Smoke
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Money is a good and smoke is a bad for Agent B.
Air pollution. Water pollution. Loud parties next door. Traffic congestion. Second-hand cigarette smoke. Increased insurance premiums due to alcohol
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Inefficiency & Negative Externalities
A’s most Smoke preferred choice Smoke
is inefficient
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Efficient allocations
微观经济之外部效应培训讲义
Externalities and Property Rights
Causing a producer of an externality to bear the full external cost or to enjoy the full external benefit is called internalizing the externality(外 部效应内部化).
Externalities and Efficiency
Externalities cause Pareto inefficiency; typically – too much scarce resource is allocated to an activity which causes a negative externality – too little resource is allocated to an activity which causes a positive externality.
Externalities and Property Rights
An externality is viewed as a purely public commodity.
A commodity is purely public if – it is consumed by everyone (nonexcludability), and – everybody consumes the entire amount of the commodity (nonrivalry in consumption).
Either there is too much smoke (A’s most preferred choice) or there is too little smoke (B’s choice).
微观经济之外部效应培训讲义
Examples of Positive Externalities
A well-maintained property next door that raises the market value of your property.
A pleasant cologne or scent worn by the person seated next to you.
Money is a good and smoke is a bad for Agent B.
Smoke is a purely public commodity.
Consumption Externality
Agent A is endowed with $yA. Agent B is endowed with $yB. Smoke intensity is measured on a
Externalities and Property Rights
An externality is viewed as a purely public commodity.
A commodity is purely public if – it is consumed by everyone (nonexcludability), and – everybody consumes the entire amount of the commodity (nonrivalry in consumption).
E.g. a broadcast television program.
Consumption Externality
Pareto efficient amount of smoke Inefficient equilibrium with negative
平狄克《微观经济学》(第7版)笔记(第18章-外部性与公共品)
平狄克《微观经济学》〔第7版〕第18章外部性与公共品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珍贵的财富，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。
1．外部性外部性指一个经济活动的主体对它所处的经济环境的影响。
外部性的影响会造成私人成本和社会成本之间，或私人收益和社会收益之间的不一致，因此容易造成市场失灵。
外部性的影响方向和作用结果具有两面性，外部性可以是负的——当一方的行动使另一方付出代价时；也可以是正的——当一方的行动使另一方受益时。
〔1〕负外部性和无效率：边际社会成本当存在负的外部性时，边际社会成本MSC大于边际私人成本MC。
差额就是边际外部成本MEC。
从社会的角度看，具有负外部性的厂商生产的产出太多了。
有效产出水平应当是价格等于生产的边际社会成本——边际生产成本加上边际外部成本。
外部性既导致短期也导致长期的无效率。
当产品的价格高于生产的平均成本时，厂商就进入一个竞争性产业，而当价格低于平均成本时，厂商就退出。
在长期均衡中，价格等于〔长期〕平均成本。
当存在负的外部性时，平均私人生产成本低于平均社会成本。
结果，即使是在某些厂商离开产业才有效率时，这些厂商还是留在产业内。
因而，负的外部性鼓励太多的厂商留在产业内。
〔2〕正的外部性和无效率：外在收益当存在正的外部性时，边际社会收益MSB大于边际私人收益D。
差额就是边际外部收益MEB。
边际社会收益曲线MSB是通过把每个产出水平上的边际私人收益和边际外部收益相加得到的。
简言之，M SB D M EB=+。
有效产出水平*q处于MSB和MC曲线的相交处。
正的外部性也会导致无效率。
一个正的外部性的例子就是厂商在研究与开发〔R&D〕上所花费的钱。
微观经济学 第10章 外部性
管制和庇古税
经济学家还认为，庇古税对环境更有利。在命 令与控制的管制政策下，一旦工厂达到了300 吨污染物的目标就没有理由再减少排污。与此 相比，税收激励工厂去开发更清洁的技术，因 为更清洁的技术可以减少工厂不得不支付的税 收量。 庇古税与大多数其他税不同。庇古税是存在外 部性时的正确激励，从而使资源配置接近于社 会最优。因此，庇古税增加了政府的收入，也 提高了经济福利。
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市场为基础的政策
可交易的污染许可：允许排污权在企业
间自愿交易 。
从经济效率的观点看，允许这种交易是一 种好政策。这个交易必然使这两个厂所有 者的状况变好，因为它们是自愿对此达成 一致的。 这种交易没有任何外部影响，因为污染总 量仍然是相同的。因此，通过允许造纸厂 把自己的排污权出卖给钢铁厂可以提高社 会福利。
科斯定理说明，私人经济主体可以解决他 们之间的外部性问题。无论最初的权利如何分 配，有关各方总可以达成一种协议，在这种协 议中每个人的状况可以变好，而且结果是有效 率的。
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交易成本
交易成本（Transaction costs）：
各方在协议与遵守协议过程 中所发生的成本 。
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为什么私人解决方法并不是总有效
第4篇 公共部门经济学
第10章 外部性 第11章 公共物品和公共资源 第12章 税制的设计
第10章 外部性
考虑下面事情
钢铁厂生产钢铁赚得利润，但是产生了二氧化 硫，看不见的手可以阻止其排放过多的二氧化 硫吗？。 每年国庆，北京的天安门广场、上海的世纪公 园都会燃放烟火，有成千上万的人观看。为什 么没有企业以收门票的方式来进行商业运作呢 ？
18
生产中的正外部性