chapter11 Public Goods and Common Resources
Public Goods and Common Resources
公共物品和公有资源
Chapter 11
“生活中最美好的东西都是免费的. . .”
免费物品向经济分析提出了特殊的挑战
Most goods in our economy are allocated in markets…
“The best things in life are free. . .”
当一些物品可以免费得到时，在正常情况下配置经济中资源的市场力量就不存在了.
“The best things in life are free. . .”
当一种物品没有价格时，私人市场不能保证该物品生产和消费的适当数量.
“The best things in life are free. . .”
在这种情况下，政府政策可以潜在的解决市场失灵问题，并增进经济福利.
The Different Kinds of Goods
When thinking about the various goods in the economy, it is useful to group them according to two characteristics:
◆Is the good excludable（排他性的）?
◆Is the good rival（竞争性的）?
The Different Kinds of Goods
◆Excludability-排他性
◆阻止人们使用某些物品.
◆Laws recognize and enforce private p roperty rights-产权.
The Different Kinds of Goods
◆Rivalness-竞争性
◆一个人使用某种物品会减少其他人对该物品的使用.
物品的四种类型
◆Private Goods-私人物品
◆Public Goods-公共物品
◆Common Resources-公有资源
◆Natural Monopolies-自然垄断
Types of Goods
◆Private Goods
◆A re both excludable and rival.
◆Public Goods
◆Are neither excludable nor rival.
Types of Goods
◆Common Resources
◆Are rival but not excludable.
◆Natural Monopolies
◆Are excludable but not rival.
Types of Goods
The Free-Rider Problem
搭便车者问题
A free-rider 搭便车者是指得到一种物品的利益但避开为此付费的人.
The Free-Rider Problem
◆Since people cannot be excluded from enjoying the benefits of a public good, individuals may withhold paying for the good hoping that others will pay for it.
◆搭便车者问题的存在使私人市场无法提供公共物品.
解决搭便车者问题
◆如果政府确信一种公共物品的利益大于成本，它就可以提供该公共物品.
◆政府能够提供公共物品并使每个人的状况变好，通过用税收说如对公共物品进行支付.
一些重要的公共物品
◆National Defense-国防
◆Basic Research-基础研究
◆Programs to Fight Poverty-反贫困计划
灯塔是公共物品吗?
Cost-Benefit Analysis-成本-收益分析
◆In order to decide whether to provide a public good or not, the total benefits of all those who use the good must be compared to the costs of providing and maintaining the public good.
◆Cost benefit analysis 比较提供一种公共物品的社会成本和社会收益的研究.
Cost-Benefit Analysis
◆A cost-benefit analysis would be used to estimate the total costs and benefits of the project to society as a whole.
◆成本收益分析是很困难的因为用于比较成本和收益的价格不存在.
◆T he value of life, the consumer’s time, and aesthetics（美学，审
美）are difficult to assess（估计）.
Common Resources
公有资源
公有资源与公共物品一样，也没有排他性：想使用共有资源的任何一个人都可以免费使用.
Common Resources
公有资源在消费中竞争性：一个人使用公有资源就减少了其他人对它的享用.
Tragedy of the Commons
公有地悲剧
公有地悲剧是一个寓言，说明从整个社会的角度看，为什么公有资源的使用大于合意的水平.
◆Common resources tend to be used excessively when individuals
are not charged for their usage.
◆This creates a negative externality.
◆Clean air and water
◆Oil pools-油床
◆Congested roads-拥挤的公路
◆Fish, whales, and other wildlife-鱼、鲸和其他野生动物
为什么黄牛没有绝种?
产权的重要性
在所有情况下，市场没有有效的配置资源，是因为没有很好的建立产权.
某些有价值的东西并没有在法律上有权控制它的所有者.
Importance of
Property Rights
当产权缺失引起市场失灵时，政府可以潜在的解决这个问题.