公共财政学之外部性

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,*,1,Public Finance,Chapter 5 Externalities,胡春雷,Introduction of the Chapter,Externality&Public finance,1)Externality is one of the factors leading to market failure that should be rectified by the public sector;,2)Public goods is a special kind of externality;,3)The rectification of externality partly depends on public finance.,2,3,本章基本框架,外 部 性,外部性的规范分析,外部性的解决方案,外部性的,基本认识,研究方法与理论基础,基本概念,性质,类型及影响因素,Efficiency,Income distribution,4,I What is an externality?,外部性,（,Externalities,）,When the activity of one entity(a person or a firm)directly affects the welfare of another in a way that is outside the market mechanism,that effect is called an Externality.,(P82),The Nature of Externalities,Entities:,a person or a firm(,consumers as well as firms),；,Reciprocal;,Types:Positive and negative;,Public goods:a special kind of externality.,Market failure,：,positive failure&negative failure.,Others:the type of externality is related to entity s utility.,5,6,负外部性,(negative externality),一个人的行为对旁观者的福利产生了不利的影响，但这个人对这种影响不付报酬。

工厂对空气的污染,邻居的狗叫声,深夜里邻居吵闹的立体声,建设工地的噪声污染,二手烟对健康的危害,驾车时打使路人更不安全,7,正外部性,(positive externality),一个人的行为对旁观者的福利产生有利的影响，但这个人对这种影响得不到报酬接种预防传染病的疫苗不仅保护你自己，而且,保护了与你密切接触的其他人,创造出了别人也可以使用的知识,人们上大学提高了教育水平，并减少了犯罪和改善了政府,感谢你没有污染水果的供应！,外部性的经济影响：效率,的,损失,存在外部效应时，私人的边际收益（,MPB,）和边际成本（,MPC,）与社会的边际收益（,MSB,）和边际成本（,MSC,）发生偏离决定个人和厂商的经济选择是私人边际收益和私人边际成本个人和厂商仅从自身利益出发，忽略外部效应带给他人的效益和成本，决策使资源配置失误II Research approach and theory base,研究方法：基于个体主义,(individualism),的规范分析与演绎分析,(Deduction analysis),；,理论基础：新古典边际主义,9,III Formal Analysis,Analysis base:negative externality,Key words:MSC;MD;welfare gains and losses.,Implications,Dilemmas.,10,11,0,Q,*,Q,1,Q,P,Externality,MB,MPC,MSC,Implications,Private market does not produce the socially efficient output level,Gains and losses of the benefit,Zero pollution is not socially desirable,The actual locations and shapes of the curves in this map is hard to be determined,MD,Three W questions,What activities produce pollutants?,The types and quantities of pollution associated with production processes must be identified;,Which pollutants do harm?,What is the value of the damage done?,12,13,Conclusions,An interdisciplinary approach should be investigated in a pollution problem.,Marginal analysis is available to make efficient decisions in pollution problem,14,IV,Responses to externality,1,、,Private responses,（,P88,）,2,、,Public responses,（,P92,）,Private responses,Bargaining and Coase Theorem,two assumptions of this response:,The cost of bargaining(Transaction Cost)is low;,Damages can be identified and legally prevented.,15,16,科斯（,RONALD H.COASE,）,美国芝加哥大学教授，,1991,诺贝尔经济学奖得主。

科斯定理,（,The Coase Theorem),：如果产权得到明确界定，如果协商或谈判等活动发生的交易成本为零，那么在有外部性效应的市场上，无论所涉及,的,资源的产权属于哪一方，交易双方总能够通过协商谈判达到资源配置有效率状态P90),for his discovery and clarification of the significance of transaction costs and property rights for the institutional structure and functioning of the economy,Other assumptions,Only a few parties involved,The sources of externality are well defined,Income distribution,Property rights are valuable,Qualifications and Limitations to Coase Theorem,17,Mergers:Externality internalized.,to coordinate the activities of the parties.,Social Conventions:To do or not to do is a problem.,理论工具不足，对社会习俗的经济机制分析可能需要引入新制度经济学与博弈论,18,Public responses,Public approaches to resolve externality,Taxes:externality internalized,Pigouvian tax system,19,20,Q,0,P,P,Q*,Pigouvian tax&subsidies,2,.,它与市场需求曲线共同决定了污染量,d,MSC,MPC+cd,MPC,MD,MB,c,e,f,Application of Piouvian tax,pollution&traffic jam,Shortages:,Inverse stimuli:free rider.,Practical problems of the system:,tax rate and marginal damage function is hard to be determined.,21,Pigouvian subsidy,The efficiency can be obtained by paying the fixed number of polluters not to pollute with a rising of their effective production cost.,Comparison between taxes&subsidies.,Efficiency&Fairness,22,Creating a market,Market for pollution rights,23,0,Z*,Dz,Sz,P,Regulation two polluters,24,Q,0,P,P,X*,MPCx+d=MPCz+d,MPC,X1=Z1,Z*,MBz,MBx,d,25,Comparison between regulation,&subsidy,：,从社会减少污染总水平上，,regulation,和,subsidy,同样有效,。

但效率不同,：不同的工厂减少污染的成本不同subsidy,把污染权分配给减少污染成本最高的企业所以,subsidy,优于,regulation,同时，激励也不同,regulation,规定了污染的水平，,subsidy,给生产者减少污染的激励激励生产者开发更清洁的技术但实际操作中，合适的排放费很难确定,Implications for income distribution,Who benefits?,the poor&the rich,Who bears the cost?,1,、,unemployment of polluters workers;,2,、,expensive products,3,、,others,26,V,正外部性与市场失灵,在外部经济时，利益是共享的、非排他性的，因此是无价的，也就脱离了定价机制之外由于行为人没有因产生的外部利益而得到补偿，在决定采取行动的水平时就没有将外部利益考虑进去的动机个人和厂商的行动选择在这样的水平上：其从行动中获得的边际收益恰好等于采取行动的边际成本这样就忽略了同时外溢给其他人的边际收益其结果是产生供给不足的市场失灵Positive externality,D,S,=MSB,C,MC,a,D,A,=MPB,P,O R1,R*,Research,b,MEB,MPB,c,d,MSB=MPB+MEB,The effects of positive externalities,Positive externalities generally lead to underprovision of an activity.,A subsidy can correct the problem but probably with inefficiency.,29,几点感想,在相当多的外部性问题上，科斯定理具有启发意义，但不可作为灵丹妙药,我国学者、决策者对外部性的分析往往集中在效率上，往往忽视了外部性对收入分配的影响,外部性的纠正需要多。