清华经济学原理课件6市场和政府政策.ppt

第六章 Chapter 6市场与政府政策 Markets and Government Policies2市场与政府政策 Markets and Government Policies经济学家的作用之一是运用他们的理论帮助制定 政府政策 One of the roles of economists is to use their theories to assist in the development of policies.实证分析的重要性：政府政策会不会事与愿违？ Importance of Positive Analysis: Would government policies have effects their architects did not intend or anticipate?供求曲线作为分析工具 Analyze various types of policy using only the tools of supple and demand3市场与政府政策 Markets and Government Policies在自由的、无管制的市场中，市场的力量建立均 衡价格，决定交换的数量。

In a free, unregulated market system, market forces establish equilibrium prices and exchange quantities.虽然均衡的状态可能是有效率的，但可能并非每 个人都满意 While equilibrium conditions may be efficient, it may be true that not everyone is satisfied. 4价格控制 Price Controls.实行价格控制通常是政府相信市场价格对 买方或卖方不公平 Are usually enacted when policymakers believe the market price is unfair to buyers or sellers. 两种价格控制：价格上限和价格下限 Result in government-created price ceilings and floors. 5价格上限与价格下限 Price Ceilings & Price Floors价格上限（Price Ceiling）法定最高价格。

A legally established maximum price at which a good can be sold. 价格下限（Price Floor）法定最低价格 A legally established minimum price at which a good can be sold.6价格控制在中国 Price Control in China价格上限经济适用（限价）房或廉租房药品降价令化肥限价价格下限粮食保护价民航机票禁折令对移动通话费降价的限制7价格上限 Price Ceilings政府实行价格上限时有两种可能结果 Two outcomes are possible when the government imposes a price ceiling:当价格上限高于均衡价格时，价格上限没有限制性 The price ceiling is not binding if set above the equilibrium price. 当价格上限低于均衡价格时，价格上限有限制性， 导致短缺。

The price ceiling is binding if set below the equilibrium price, leading to a shortage. 8约束条件分类 Types of Constraints没有限制作用的约束条件 A non-binding constraint有限制作用的约束条件 A binding constraint没有限制作用的价格上限 A Price Ceiling That Is Not Binding.$4$3Quantity of Ice-Cream Cones0Price of Ice-Cream Cone需求需求DemandDemand供给供给SupplySupply价格上限 Price ceiling均衡价格 Equilibrium price100均衡数量 Equilibrium quantity有限制作用的价格上限 A Price Ceiling That Is Binding.$3Quantity of Ice-Cream Cones0Price of Ice-Cream Cone$2DemandSupply均衡价格均衡价格 EquilibriumEquilibrium priceprice价格上限价格上限 PricePrice ceilingceiling短缺短缺 ShortageShortage125Quantity Demanded 需求量75Quantity Supplied 供给量11实行价格上限的结果 Effects of Price Ceilings有限制作用的价格上限导致短缺 A binding price ceiling creates shortages 因为需求量大于供给量 because QD > QS.12实行价格上限的结果 Effects of Price Ceilings有限制作用的价格上限导致配给 A binding price ceiling creates rationing 因为有短缺 Because of shortage 配给的方式： Ø排队 queuing Ø票证 coupons Ø审批 examine and approve Ø“走后门” going through a “back door” Ø卖者对买者的歧视 discrimination13加油站前的长队 Lines at the Gas Pump在1973年欧佩克提高了原油的世界市场价格 。

因为原油是制造汽油的主要原料，更高的 油价减少了汽油的供给 In 1973 OPEC raised the price of crude oil in world markets. Because crude oil is the major input used to make gasoline, the higher oil prices reduced the supply of gasoline.谁应该为加油的长队负责？ What was responsible for the long gas lines?14价格上限没有限制性 The Price Ceiling on Gasoline Is Not Binding$4P1Quantity of Gasoline0Price of GasolineQ1DemandSupplyPrice Ceiling 价格上限1. Initially, the price ceiling is not binding. 开始时价格上 限没有限制性15价格上限变为有限制性 The Price Ceiling on Gasoline Is BindingP1Quantity of Gasoline0Price of GasolineQ1需求 DemandS1价格上限 Price ceilingS22. 当供给减少 时…but when supply falls.P23. 价格上限变为限 制性的…the price ceiling becomes binding.4.导致短缺 …resulting in a shortage.16谁为短缺负责？ Who Should Be Blamed for Shortages?供给下降或需求增加本身不会导致短缺。

A decrease in supply or increase in demand cannot cause a shortage by itself.经济学家认为是政府的价格控制政策导致的短缺 Economists blame government price controls that limited the price the seller could charge for the shortages.即使价格上限的目的是帮助买者，但并非所有买者都 从中受益 Even though the price ceiling was motivated by a desire to help buyers, not all buyers benefit from the policy.结果既无效率，也可能不公平 The outcome is both inefficient and potentially unfair. 17举例：房租控制 Rent Control房租控制是指房主出租房屋时所收房租的上 限。

Rent controls are ceilings placed on the rents that landlords may charge their tenants.房租控制的目的是帮助穷人，使他们能负得 起房租 The goal of rent control policy is to h。