正外部性的例子 铝市场 Examples of Positive The Market for Aluminum Externalities 铝的价格 ◆免疫注射 Immunizations 厂麻 private cost ◆修复历史性建筑物 Restored historic buildings ◆研究新技术 Research into new technolo 名人价筐 private value) 铝的堂量8 铝市场与福利经济 铝市场与福利经济 The Market for Aluminum and The Market for Aluminum and Welfare economics Welfare economics 市场均衡时生产和消费的数量,从使 如果铝厂排污(负外部性),那么社会生产 生产者与消费者剩余之和最大化的意 铝的成本就会比铝生产者支付的成本高 义上来说,是有效率的。 If the aluminum factories emit pollution(a The quantity produced and consumed negative externality ) then the cost to society in the market equilibrium is efficient of producing aluminum is larger than the cost to aluminum producers. in the sense that it maximizes the sum of producer and consumer surplus. 铝市场与福利经济 污染与社会最优 The Market for Aluminum and Pollution and the Social Optimum. Welfare Economics 污录成 对于生产的每一单位的铝而言,社会成本包 括生产者的私人成本,加上向受到污染不利 影响的旁观者施加的成本 均衡 Equilibrium 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 CMaRKET2 7 ‹免疫注射 Immunizations ‹修复历史性建筑物 Restored historic buildings ‹研究新技术 Research into new technologies 正外部性的例子 Examples of Positive Externalities 8 铝市场 The Market for Aluminum... 铝的数量 Quantity of Aluminum 0 铝的价格 Price of Aluminum QMARKET 需求Demand (私人价值 private value) 供给Supply (厂商成本 private cost) 均衡点 Equilibrium 9 铝市场与福利经济 The Market for Aluminum and Welfare Economics 市场均衡时生产和消费的数量，从使 生产者与消费者剩余之和最大化的意 义上来说，是有效率的。 The quantity produced and consumed in the market equilibrium is efficient in the sense that it maximizes the sum of producer and consumer surplus. 10 铝市场与福利经济 The Market for Aluminum and Welfare Economics 如果铝厂排污（负外部性），那么社会生产 铝的成本就会比铝生产者支付的成本高。 If the aluminum factories emit pollution (a negative externality), then the cost to society of producing aluminum is larger than the cost to aluminum producers. 11 铝市场与福利经济 The Market for Aluminum and Welfare Economics 对于生产的每一单位的铝而言，社会成本包 括生产者的私人成本，加上向受到污染不利 影响的旁观者施加的成本。 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. QMARKET 12 污染与社会最优… Pollution and the Social Optimum… 铝数量 Quantity of Aluminum 0 铝价格 Price of Aluminum 需求Demand (私人价值private value) 供给Supply (厂商成本private cost) 社会成本 Social cost Qoptimum 污染成本 Cost of pollution 均衡Equilibrium 最优 Optimum