曼昆微观经济学分册英文版 教材PPT
Positive Externalities 正的外部性In the presence of a positive externality, the social value of a good includes private value – the direct value to buyers external benefit – the value of the positive impact on bystanders The socially optimal Q maximizes welfare: At any lower Q, the social value of additional units exceeds their cost. At any higher Q, the cost of the last unit exceeds its social value.
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