1、Public Goods and Common Resources公共物品和共有資源公共物品和共有資源 Chapter 11Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.“The best things in life are free. . .”Free goods provide a special challenge for economic analysisMost goods in our economy are allocated in marketsfor these goods, p

2、rices are the signals that guide the decisions of buyers and sellers.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.“生活中最好的東西就是免費的生活中最好的東西就是免費的”免費物品向經濟分析提出了特殊的挑免費物品向經濟分析提出了特殊的挑戰。戰。 在我們的經濟中，大部分物品是在市在我們的經濟中，大部分物品是在市場中配置的。場中配置的。對這些物品來說，價格是引導買者對這些物品來說，價格是引導買者和賣者決策的信號。和賣者決策的信號。Har

3、court, Inc. items and derived items copyright 2001 by Harcourt, Inc.“The best things in life are free. . .” “生活中最好的東西就是免費的生活中最好的東西就是免費的”When goods are available free of charge, the market forces that normally allocate resources in our economy are absent.當一些物品可以免費得到時，在正常情當一些物品可以免費得到時，在正常情況下，經濟中配置資源的市

4、場力量就不況下，經濟中配置資源的市場力量就不存在了。存在了。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.“The best things in life are free. . .” “生活中最好的東西就是免費的生活中最好的東西就是免費的”When a good does not have a price attached to it, private markets cannot ensure that the good is produced and consumed in the prope

5、r amounts.當一種物品沒有價格時，私人市場就不能當一種物品沒有價格時，私人市場就不能保證該物品生產和消費的適當數量。保證該物品生產和消費的適當數量。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.“The best things in life are free. . .” “生活中最好的東西就是免費的生活中最好的東西就是免費的”In such cases, government policy can potentially remedy the market failure that res

6、ults, and raise economic well-being.在上述情況下，政府政策可以潛在地在上述情況下，政府政策可以潛在地解決市場失靈，并增進經濟福利。解決市場失靈，并增進經濟福利。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Different Kinds of GoodsWhen thinking about the various goods in the economy, it is useful to group them according to two chara

7、cteristics:u Is the good excludable?u Is the good rival?Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.不同類型的物品不同類型的物品在考慮經濟中的各種物品時，根據兩在考慮經濟中的各種物品時，根據兩個特點來對物品分類是有用的個特點來對物品分類是有用的:u 物品有排他性嗎？物品有排他性嗎？u 物品有競爭性嗎物品有競爭性嗎?Harcourt, Inc. items and derived items copyright 2001 by Harcourt

8、, Inc.The Different Kinds of Goods不同類型的物品不同類型的物品uExcludability 排他性排他性uPeople can be prevented from enjoying the good. 可以阻止一個人使用一種物品時該物品的特性可以阻止一個人使用一種物品時該物品的特性uLaws recognize and enforce private property rights. 法律承認并對私人產權進行保護。法律承認并對私人產權進行保護。Harcourt, Inc. items and derived items copyright 2001 by Ha

9、rcourt, Inc.The Different Kinds of Goods不同類型的物品不同類型的物品u Rivalness 競爭性競爭性uOne persons use of the good diminishes another persons enjoyment of it. 一個人使用一種物品減少其他人使用時一個人使用一種物品減少其他人使用時該物品的特性。該物品的特性。 Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Four Types of Goods四種物品四種物品uPrivate

10、 Goods 私人物品私人物品uPublic Goods 公共物品公共物品uCommon Resources 共有資源共有資源uNatural Monopolies 自然壟斷自然壟斷Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Types of Goods 物品的類型物品的類型uPrivate Goods 私人物品私人物品uAre both excludable and rival. 既有排他性又有競爭性。既有排他性又有競爭性。uPublic Goods 公共物品公共物品uAre neither e

11、xcludable nor rival. 既無排他性又無競爭性。既無排他性又無競爭性。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Types of Goods 物品的類型物品的類型uCommon Resources 共有資源共有資源uAre rival but not excludable. 有競爭性但無排他性。有競爭性但無排他性。uNatural Monopolies 自然壟斷自然壟斷uAre excludable but not rival. 有排他性但無競爭性。有排他性但無競爭性。Harco

12、urt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Four Types of Goods Rival?Yes NoYes Private Goods Ice-cream cones Clothing Congested toll roads Natural Monopolies Fire protection Cable TV Uncongested toll roads No Common Resources Fish in the ocean The environment Congested nontoll

13、 roads Public Goods National defense Knowledge Uncongested nontoll roads Excludable?Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.四種物品類型四種物品類型 競爭性競爭性是是 否否是是 私人物品私人物品 冰激凌- 衣服 擁擠的收費道路 自然壟斷自然壟斷 消防 有線電視 不擁擠的收費道路 否否 共有資源共有資源 海洋中的魚 環境 擁擠的不收費道路 公共物品公共物品 國防 知識 不擁擠的不收費道路 排他性排他性Harcou

14、rt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Public GoodsnGoods that are not excludable and, therefore, are available to everyone free of charge. Externalities arise because something of value has no price attached to it. People receive benefits without having to compensate anyon

15、e for the use of scarce resources.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.公共物品公共物品n每個人都可以免費得到不具有排他每個人都可以免費得到不具有排他性的物品。性的物品。 因為具有價值的東西沒有相應的市場價因為具有價值的東西沒有相應的市場價格，從而導致了外部性。格，從而導致了外部性。 人們從使用稀缺資源中得到利益而不必人們從使用稀缺資源中得到利益而不必向任何人進行支付。向任何人進行支付。Harcourt, Inc. items and derived ite

16、ms copyright 2001 by Harcourt, Inc.The Free-Rider Problem搭便車問題搭便車問題A free-rider is a person who receives the benefit of a good but avoids paying for it.搭便車者搭便車者得到一種物品的利益得到一種物品的利益但避開為此支付的人。但避開為此支付的人。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Free-Rider ProblemuSince pe

17、ople 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.uThe free-rider problem prevents private markets from supplying public goods.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.搭便車

18、問題搭便車問題u因為不能排除個人從公共物品中享受利因為不能排除個人從公共物品中享受利益，所以他們不愿意自己支付成本，而益，所以他們不愿意自己支付成本，而希望他人支付。希望他人支付。u搭便車者問題排除了私人市場提供公共搭便車者問題排除了私人市場提供公共物品。物品。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Solving the Free-Rider ProblemuThe government can decide to provide the public good if the total b

19、enefits exceed the costs.uThe government can make everyone better off by providing the public good and paying for it with tax revenue.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.解決搭便車問題解決搭便車問題u如果政府確信，總利益大于總成本，如果政府確信，總利益大于總成本，它就可以提供公共物品。它就可以提供公共物品。u政府提供公共物品，并用稅收為它支政府提供公共物品，

20、并用稅收為它支付，這樣可以使每個人的狀況變好。付，這樣可以使每個人的狀況變好。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Some Important Public Goods一些重要公共物品一些重要公共物品uNational Defense 國防國防uBasic Research 基礎研究基礎研究uPrograms to Fight Poverty 反貧困項目反貧困項目Harcourt, Inc. items and derived items copyright 2001 by Harcour

21、t, Inc.Are Lighthouses Public Goods?燈塔是公共物品嗎？燈塔是公共物品嗎？Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Difficult Job of Cost-Benefit AnalysisuCost benefit analysis refers to a study that compares the costs and benefits to society of providing a public good.uIn order to deci

22、de 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.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.成本成本 收益分析是一個難題收益分析是一個難題u成本成本收益分析收益分析 是比較提供一種物品對整個是比較提供一種物品對整個

23、社會帶來的總收益和總成本的研究。社會帶來的總收益和總成本的研究。u為了決定是否提供某種公共物品，必須將使為了決定是否提供某種公共物品，必須將使用該公共物品的所有人得到的總利益與提供用該公共物品的所有人得到的總利益與提供并維護該項公共物品的總成本進行比較。并維護該項公共物品的總成本進行比較。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Difficult Job of Cost-Benefit AnalysisuA cost-benefit analysis would be used to

24、estimate the total costs and benefits of the project to society as a whole.uIt is difficult to do because of the absence of prices needed to estimate social benefits and resource costs.uThe value of life, the consumers time, and aesthetics are difficult to assess.Harcourt, Inc. items and derived ite

25、ms copyright 2001 by Harcourt, Inc.成本成本 收益分析是一個難題收益分析是一個難題u成本成本收益分析收益分析 用來評估一個項目給用來評估一個項目給整個社會能帶來的收益和資源成本。整個社會能帶來的收益和資源成本。u由于缺乏用來評估社會收益和資源成本的由于缺乏用來評估社會收益和資源成本的市場價格，所以成本市場價格，所以成本收益分析是一項艱收益分析是一項艱難的工作。難的工作。u生命、時間和藝術的價值很難評估。生命、時間和藝術的價值很難評估。Harcourt, Inc. items and derived items copyright 2001 by Harcour

26、t, Inc.Common Resources 共有資源共有資源Common resources, like public goods, are not excludable. They are available free of charge to anyone who wishes to use them.共有資源共有資源與公共物品一樣沒有排他性。想與公共物品一樣沒有排他性。想使用共有資源的任何一個人都可以免費使使用共有資源的任何一個人都可以免費使用。用。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, I

27、nc.Common Resources 共有資源共有資源Common resources are rival goods because one persons use of the common resource reduces other peoples use.共有資源共有資源具有競爭性，因為一個人使用具有競爭性，因為一個人使用共有資源就減少了其他人對它的享用。共有資源就減少了其他人對它的享用。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Tragedy of the CommonsThe T

28、ragedy of the Commons is a parable that illustrates why common resources get used more than is desirable from the standpoint of society as a whole.uCommon resources tend to be used excessively when individuals are not charged for their usage. uThis creates a negative externality.Harcourt, Inc. items

29、 and derived items copyright 2001 by Harcourt, Inc.共有地的悲劇共有地的悲劇共有地的悲劇共有地的悲劇一個寓言，說明從整一個寓言，說明從整個社會的角度看為什么共有資源的使用個社會的角度看為什么共有資源的使用大于合意的水平。大于合意的水平。u當個人免費使用共有資源時，共有資源當個人免費使用共有資源時，共有資源往往被過度使用。往往被過度使用。 u這就產生了這就產生了負外部性負外部性。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Examples of Co

30、mmon Resources共有資源的例子共有資源的例子uClean air and water 清潔空氣和水清潔空氣和水uCongested roads 擁擠的道路擁擠的道路uFish, whales, and other wildlife 魚類、鯨魚和其他野生動物魚類、鯨魚和其他野生動物Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Why Isnt the Cow Extinct?為什么黃牛沒有絕種？為什么黃牛沒有絕種？Private Ownership and the Profit Motiv

31、e!私人產權和利益驅動私人產權和利益驅動Will the market protect me?市場保護我嗎市場保護我嗎?Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Conclusion: Importance of Property RightsThe market fails to allocate resources efficiently when property rights are not well-established (i.e. some item of value does n

32、ot have an owner with the legal authority to control it).Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.結論：產權的重要性結論：產權的重要性 當沒有很好地建立產權時當沒有很好地建立產權時（這（這就是說，某些有價值的東西并沒有就是說，某些有價值的東西并沒有在法律上有權控制它的所有者）在法律上有權控制它的所有者） ，市場就不能有效地配置資源。市場就不能有效地配置資源。Harcourt, Inc. items and derived items co

33、pyright 2001 by Harcourt, Inc.Conclusion: Importance of Property Rights結論：產權的重要性結論：產權的重要性When the absence of property rights causes a market failure, the government can potentially solve the problem.當沒有產權而引起市場失靈時，政府可當沒有產權而引起市場失靈時，政府可以潛在地解決這個問題。以潛在地解決這個問題。Harcourt, Inc. items and derived items copyri

34、ght 2001 by Harcourt, Inc.SummaryuGoods differ in whether they are excludable and whether they are rival.uA good is excludable if it is possible to prevent someone from using it.uA good is rival if one persons enjoyment of the good prevents other people from enjoying the same unit of the good.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.小結小結u物品的差別在于它們是否具有排他性物品的差別在于它們是否具有排他性和是否具有競爭性。和是否具有競爭性。u如果排除某個人使用某種物品是可能如果排除某個人使用某種物品是可能的，這種物品就具有排他性。的，這種物品就具有排他性。u如