科斯定理认为在什么条件下外部性可由私人协商解决？
Under what conditions does the Coase theorem say externalities can be solved by private bargaining?
当产权界定清晰、交易成本足够低、且相关方能够自由协商时，无论初始权利归谁，当事人都能达成有效率的结果；现实中交易成本和集体行动问题常使其难以实现。
When property rights are clear, transaction costs are low, and parties can bargain freely, an efficient outcome is reached regardless of who holds the initial right; in practice, transaction costs and collective-action problems often block this.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
N. Gregory Mankiw,《Principles of Economics》第8版,Cengage,2017;中译《经济学原理》北京大学出版社
N. G. Mankiw, Principles of Economics, 8th ed., Cengage, 2017; Chinese ed. Peking University Press
独立核验依据 · Independent verification: 核验依据 2 cengage.com
#科斯定理 #交易成本
正外部性和负外部性有什么不同？
How do positive and negative externalities differ?
负外部性是行为给旁人带来成本（如污染），正外部性是带来收益（如接种疫苗保护他人）；市场往往生产过多负外部性、过少正外部性。
Negative externalities impose costs on others (e.g., pollution); positive ones create benefits (e.g., vaccination protecting others). Markets tend to produce too much of the former and too little of the latter.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
N. Gregory Mankiw,《Principles of Economics》第8版,Cengage,2017;中译《经济学原理》北京大学出版社
N. G. Mankiw, Principles of Economics, 8th ed., Cengage, 2017; Chinese ed. Peking University Press
独立核验依据 · Independent verification: 核验依据 2 cengage.com
#正外部性 #负外部性
污染税（庇古税）是如何“内化”外部性的？
How do pollution taxes (Pigouvian taxes) "internalize" externalities?
通过对污染等负外部性征税，把社会成本计入生产者价格，使其减少过量排放；税额通常应等于边际外部损害。
By taxing pollution and similar negative externalities, the social cost is added to the producer's price, discouraging excess; the tax ideally equals marginal external damage.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
N. Gregory Mankiw,《Principles of Economics》第8版,Cengage,2017;中译《经济学原理》北京大学出版社
N. G. Mankiw, Principles of Economics, 8th ed., Cengage, 2017; Chinese ed. Peking University Press
独立核验依据 · Independent verification: 核验依据 2 cengage.com
#庇古税 #内化
什么是“外部性”？
What is an "externality"?
外部性指一个人的行为给不相关的旁人带来好处或坏处，而双方并没有为此付钱或收钱。
An externality is when someone's action creates benefits or harms for uninvolved bystanders, without money changing hands.
难度 入门 · 适合 幼儿(3-6)
CC BY 4.0 · 已核验 · Verified 2026-10-03 · 3 条独立证据
来源 · Source
N. Gregory Mankiw,《Principles of Economics》第8版,Cengage,2017;中译《经济学原理》北京大学出版社
N. G. Mankiw, Principles of Economics, 8th ed., Cengage, 2017; Chinese ed. Peking University Press
独立核验依据 · Independent verification: 核验依据 2 cengage.com
#外部性 #第三方