供求分析的重要性 供给、需求与政府政策 Supply, Demand and ◆供求分析框架具有广泛而重要的运用。 A little knowledge goes a long way Government policies ◆价格控制、税收等政府(微观)政策 市场的福利特性:规范分析 ◆国际贸易 第6章 ◆外部性(市场不完美之一) ◆断(市场不完美之二) Chapter 6 ◆扩展到各类市场:劳动市场、金融市场 ◆扩展到宏观经济:一般均衡分析 供给、需求与政府政策 Supply, Demand, and Government 价格控制 Policies Price Controls 在自由的、无管制的市场中,市场的力量建立均衡价格, ◆实行价格控制通常是政府相信市场价格对 决定交换的数量 买方或卖方不公平。 In a free, unregulated market system, market forces establish equilibrium prices and exchange quantities. Are usually enacted when policymakers ●虽然均衡的状态可能是有效率的 许并非使每人都满 believe the market price is unfair to buyers or sellers. While equilibrium conditions may be efficient, it may be true that not everyone is satisfied. ◆两种价格控制:价格上限和价格下限 ◆经济学家的作用之一是运用他们的理论助制定政府政策 Result in government-created price One of the roles of economists is to use their theories to ceilings and floors. assist in the development of policies. 价格上限与价格下限 Price Ceilings Price Floors 价格控制在中国 价格上限( Price Ceiling) 经济适用房 ◆法定最高价格。 ◆粮食保护价、化肥限价 A legally established maximum price at which a good can be sold. 价格下限( Price floor) ◆“看病难,看病贵 ◆法定最低价格 A legally established minimum price at which a good can be sold
1 1 第6章 Chapter 6 供给、需求与政府政策 Supply, Demand and Government Policies 2 供求分析的重要性 供求分析框架具有广泛而重要的运用。 A little knowledge goes a long way. 价格控制、税收等政府（微观）政策 市场的福利特性：规范分析 国际贸易 外部性（市场不完美之一） 垄断（市场不完美之二） 扩展到各类市场：劳动市场、金融市场 扩展到宏观经济：一般均衡分析 3 供给、需求与政府政策 Supply, Demand, 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，但也许并非使每人都满 意。 While equilibrium conditions may be efficient, it may be true that not everyone is satisfied. 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. 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 经济适用房 粮食保护价、化肥限价 “看病难，看病贵
价格上限 约束条件分类 Price Ceilings Types of Constraints 政府实行价格上限时有两种可能结果 ◆没有限制作用的约束条件(约束条件没有 Two outcomes are possible when the 限制性) government imposes a price ceiling A non-binding constraint(The constraint ◆当价格上限高均衡价格时,价格上限没有限侧性 is not binding) not binding if set above the 有限制作用的约束条件(约束条件有限制 ◆插缺限均衡价格时,价格上限查 a binding constraint (The constraint is The price ceiling is hinding if set helan the quilibrium price, leading to a shortage. 没有限制作用的价格上限 有限制作用的价格上限 A Price Ceiling That Is Not Binding A Price Ceiling That Is Binding. 供 Supply pply 价薇上限 Eib rigm 供量 量 Cones 实行价格上限的结果 实行价格上限的结果 Effects of Price Ceilings Effects of Price Ceiling 有限制作用的价格上限导致短缺 有限制作用的价格上限导致配给 a binding price ceiling creates A binding price ceiling creates shortages 因为需求量大于供给量 rationing because @p>Q 因为有短缺 Because of shortage 举例 举例: 70年代:食品 >80年代:原材料(如钢铁) 卖着对买着的歧视 discrimination >90年代:发售原始股 >纂证 coupons >审批 examine and approve >“走后门” going through a“ back door
2 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（约束条件没有 限制性） A non-binding constraint (The constraint is not binding) 有限制作用的约束条件（约束条件有限制 性） A binding constraint (The constraint is binding) 没有限制作用的价格上限 A Price Ceiling That Is Not Binding... $4 3 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone 需求Demand 供给Supply 价格上限 Price ceiling 均衡价格 Equilibrium price 100 均衡数量 Equilibrium quantity 有限制作用的价格上限 A Price Ceiling That Is Binding... $3 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone 2 Demand Supply 均衡价格 Equilibrium price 价格上限 Price 短缺 ceiling Shortage 125 Quantity demanded 75 Quantity supplied 供给量 需求量 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. 举例： ¾ 70年代：食品 ¾ 80年代：原材料（如钢铁） ¾ 90年代：发售原始股 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 举例： ¾排队 queuing ¾卖者对买者的歧视 discrimination ¾票证 coupons ¾审批 examine and approve ¾“走后门” going through a “back door
谁应该对排长队负责? 价格上限没有限制性 谁应该对走后门负责? The Price Ceiling on Gasoline Is Not Binding 经济学认为是政府的价格控制政策 Economists blame government price controls that limited the price the seller could charge 既无效率,也未必公平 价格上限变为有限制性 举例:房租控制 Rent Contro e Price Ceiling on Gasoline Is Binding ◆房租控制是指房主出租房屋时所收房租的上 2.当做哈渺少 ply falls.. Rent controls are ceilings placed on the rents a ◆房租控制的目的是帮助穷人,使他们能负得 The goal of rent control policy is to help the poor by making housing more affordable. 名经济学家称房租控制是“除了炸弹外推毁 座城市的最好的方法”。 高求 Demand One economist called rent control "the best way to destroy a city, other than bombing. asoline 房租控制在短期内的结果 房租控制在长期内的结果 Rent Control in the short run Rent Control in the Long Run 段e 因为供给和需求较为有 给和需求较为 供给 Supply apartments are demand for 的短快 刹的房粗 Controlled ent control
3 13 谁应该对排长队负责？ 谁应该对走后门负责？ 经济学认为是政府的价格控制政策 Economists blame government price controls that limited the price the seller could charge. 既无效率，也未必公平 14 价格上限没有限制性 The Price Ceiling on Gasoline Is Not Binding $4 P1 Quantity of Gasoline 0 Price of Gasoline Q1 Demand Supply Price 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 Binding P1 Quantity of Gasoline 0 Price of Gasoline Q1 需求 Demand S1 价格上限 Price ceiling S2 2. 当供给减少 时…but when supply falls... P2 3. 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 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 help the poor by making housing more affordable. 一名经济学家称房租控制是“除了炸弹外摧毁 一座城市的最好的方法”。 One economist called rent control “the best way to destroy a city, other than bombing.” 17 房租控制在短期内的结果 Rent Control in the Short Run... 数量 Quantity of Apartments 0 房租 Rental Price of Apartment 需求Demand 供给Supply Controlled rent受控制的房租 短缺 Shortage 供给和需求较为 缺乏弹性 Supply and demand for apartments are relatively inelastic 18 房租控制在长期内的结果 Rent Control in the Long Run... Quantity of Apartments 0 Rental Price of Apartment Demand Supply 控制的房租Controlled rent 短缺 Shortage 因为供给和需求较为有 弹性 Because the supply and demand for apartments are more elastic... 房租控制导致严 重的短缺 rent control causes a large shortage
价格下限 没有限制作用的价格下限 Price Floors A Price Floor That Is Not Binding 政府实行价格下限时有两种可能结果。 When the government imposes a price floor, Supply two outcomes 的下逝价格时:下腰出面理:m 当价格下限高于衡价格时,价格下限有限制性导致 The price floor is binding if set above the equilibrium 有限制作用的价格下限 A Price Floor That Is Binding 实行价格下限的结果 Effects of a Price Floor 价格下限阻止供给和需求向均衡价格 和数量移动。 过 Surplus A price floor prevents supply and 价格下限 demand from moving toward the Price floor equilibrium price and quantity 市场价格最多降到价格下限 When the market price hits the floor, it Demand can fall no further and the market price equals the floor price. 实行价格下限的结果 最低工资 Effects of a price floor The Minimum Wage 有限制作用的价格下限导致过剩,因为供给量大 于需求量。 a binding price floor causes a surplus because Os 价格下限的一个重要例子是最低工资 An important example of a price 非价格的配绘机制:使用歧视性标准配给物品 floor is the minimum wage. nonprice rationing is an alternative mechanism for 最低工资法规定任何廣主必须支付受 atoning the good, using discrimination criteria. 廣者的最低价格 例子:最低工资、农产品保护价格 Minimum wage laws dictate the Examples: The minimum wage, Agricultural lowest price possible for labor that price supports any employer may pay
4 19 价格下限 Price Floors 政府实行价格下限时有两种可能结果。 When the government imposes a price floor, two outcomes are possible. 当价格下限低于均衡价格时，价格下限没有限制性。 The price floor is not binding if set below the equilibrium price. 当价格下限高于均衡价格时，价格下限有限制性，导致 过剩。 The price floor is binding if set above the equilibrium price, leading to a surplus. 20 没有限制作用的价格下限 A Price Floor That Is Not Binding... $3 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone 100 Equilibrium quantity Equilibrium price Demand Supply 价格下 限 Price floor 2 有限制作用的价格下限 A Price Floor That Is Binding... $3 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone Equilibrium price Demand Supply 价格下限 Price floor $4 120 Quantity supplied 80 Quantity demanded 过剩Surplus 22 实行价格下限的结果 Effects of a Price Floor 价格下限阻止供给和需求向均衡价格 和数量移动。 A price floor prevents supply and demand from moving toward the equilibrium price and quantity. 市场价格最多降到价格下限。 When the market price hits the floor, it can fall no further, and the market price equals the floor price. 23 实行价格下限的结果 Effects of a Price Floor 有限制作用的价格下限导致过剩，因为供给量大 于需求量。 A binding price floor causes a surplus because QS >QD. 非价格的配给机制：使用歧视性标准配给物品。 nonprice rationing is an alternative mechanism for rationing the good, using discrimination criteria. 例子：最低工资、农产品保护价格 Examples: The minimum wage, Agricultural price supports 24 最低工资 The Minimum Wage 价格下限的一个重要例子是最低工资 An important example of a price floor is the minimum wage. 最低工资法规定任何雇主必须支付受 雇者的最低价格 Minimum wage laws dictate the lowest price possible for labor that any employer may pay
最低工资 最低工资 The Minimum Wage The Minimum Wage 自由劳动市场 有限制性最低工资的劳动市场 A Free Labor Market Wage A Labor Market with a Minimum 劳动供 Labor 动过(先业) 劳动备求 Labor 动量 Quantity quantity quantty quantity of 税收 税收 T axes Taxes ◆税收归宿(负担)研究谁承受税收负担 Tax incidence is the study of who bears the burden of a tax 政府用征税方式来为公共项 ◆税收改变市场均衡。 目筹款。 Taxes result in a change in market Governments levy taxes to librium raise revenue for public ◆不管向谁征税,税收总使得买者付出更 多而卖者得到更少。 projects. Buyers pay more and sellers receive less regardless of whom the tax is levied on 向买者征税的结果 向买者征税的结果 Impact of a 50c Tax Levied on Buyers Impact of a 50c Tax Levied on Buyers Price of Price ofI pply, s Supply, S, H Tax(s0.50) 收时的均 the tax s(s.so) 实者得到的价格
5 25 最低工资 The Minimum Wage 劳动量Quantity of Labor 0 工资Wage 均衡工资 Equilibrium wage 劳动需求Labor demand 劳动供给Labor supply 自由劳动市场 A Free Labor Market 均衡就业 Equilibrium employment 26 最低工资 Minimum wage 最低工资 The Minimum Wage Quantity of Labor 0 Wage Labor demand Labor supply 供给量 Quantity supplied 需求量 Quantity demanded 劳动过剩（失业） Labor surplus (unemployment) 有限制性最低工资的劳动市场 A Labor Market with a Minimum Wage 27 税收 Taxes 政府用征税方式来为公共项 目筹款。 Governments levy taxes to raise revenue for public projects. 28 税收 Taxes 税收归宿（负担）研究谁承受税收负担 Tax incidence is the study of who bears the burden of a tax. 税收改变市场均衡。 Taxes result in a change in market equilibrium. 不管向谁征税，税收总使得买者付出更 多而卖者得到更少。 Buyers pay more and sellers receive less, regardless of whom the tax is levied on. 向买者征税的结果 Impact of a 50¢ Tax Levied on Buyers... 3.00 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone 100 D1 Supply, S1 向买者征税使需求曲线 下移，幅度为税收量 A tax on buyers shifts the demand curve downward by the size of the tax ($0.50). D2 3.00 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone 90 100 $3.30 买者支付的价格 Price buyers pay D1 D2 有税收时的均衡 Equilibrium with tax Supply, S1 没有税收时的均衡 Equilibrium without tax 向买者征税的结果 Impact of a 50¢ Tax Levied on Buyers... 2.80 卖者得到的价格 Price sellers receive 无税收的 价格Price without tax Tax ($0.50)
税收的影响是什么? 向卖者征税的结果 What was the impact of tax? Impact of a 50c Tax on Sellers ◆税收抑制市场活动。 Taxes discourage market activity ◆一个商品被征税,销售量 38o TaxI tax aso,so of the 减 When a good is taxed, the without tax quantity sold is smaller. 实 ◆买卖双方都承担税收负担 Buvers and sellers share recent Demand, D, the tax burden 90100 比较向买者征税和向卖者征税的结果 税收负担 Compare the effects of taxes on The Incidence of tax sellers with those on buyers? ◆税收负担在买者和卖者间是按何种比例划分 ◆对买者征税和对卖者征税的均衡(最终) 结果是相同的 n what proportions is the burden of the tax divided? ◆买者和卖者分摊税收负担 ◆对买者征税和对卖者征税的唯一差别是谁 把钱交给政府。 答案取决子需求弹性和供给弹性 The answers to these questions depend on the elasticity of demand and the elasticity of supply. 富有弹性的供给、姚乏弹性的需求 缺乏弹性的供给、富有弹性的需求 Elastic Supply, Inelastic Demand. Inelastic Supply, Elastic Demand. 1.当供给比求更有弹性时 需求比供给更有弹性时 买支付的价格 elastic than demand Price buyers pay 买者文付韵价格 瞬器P Price without tax 图将 收的价 P哪utx 实者得到的价格 整典要 圣分操nd the tax falls more producers
6 31 税收的影响是什么？ What was the impact of tax? 税收抑制市场活动。 Taxes discourage market activity. 一个商品被征税，销售量 减小。 When a good is taxed, the quantity sold is smaller. 买卖双方都承担税收负担 Buyers and sellers share the tax burden. 3.00 Quantity of Ice-Cream Cones 0 Price of Ice-Cream Cone 90 100 S1 S2 Demand, D1 向卖者征税的结果 Impact of a 50¢ Tax on Sellers... 没有税收 的价格 Price without tax 2.80 卖者得 到的价 格Price sellers receive $3.30 买者支付 的价格 Price buyers pay 没有税收时的均衡 Equilibrium without tax 向卖者征税使供给曲 线上移，幅度为税收 量A tax on sellers shifts the supply curve upward by the amount of the tax ($0.50). Tax ($0.50) 有税收时的均衡 Equilibrium with tax 33 比较向买者征税和向卖者征税的结果 Compare the effects of taxes on sellers with those on buyers? 对买者征税和对卖者征税的均衡（最终） 结果是相同的！ 买者和卖者分摊税收负担。 对买者征税和对卖者征税的唯一差别是谁 把钱交给政府。 34 税收负担 The Incidence of Tax 税收负担在买者和卖者间是按何种比例划分 的？ In what proportions is the burden of the tax divided? 答案取决于需求弹性和供给弹性 The answers to these questions The answers to these questions depend on the elasticity of demand and the elasticity of supply. 35 富有弹性的供给、缺乏弹性的需求 Elastic Supply, Inelastic Demand... 数量 Quantity 0 价格 Price 需求 Demand 供给 Supply 税收 Tax 1. 当供给比需求更有弹性时 When supply is more elastic than demand 2. 税收负担更多 地由消费者承担 the incidence of the tax falls more heavily on consumers... 3. 更少地由 生产者承担 than on producers. 没有税收的价格 Price without tax 买者支付的价格 Price buyers pay 卖者得到的价格 Price sellers receive 36 缺乏弹性的供给、富有弹性的需求 Inelastic Supply, Elastic Demand... 0 Quantity Price Demand Supply 没有税收的价格 Price without tax 税收 Tax 1.当需求比供给更有弹性时 When demand is more elastic than supply... 2.税收负担更多 地由生产者承担 the incidence of the tax falls more heavily on producers... 3.更少地由 消费者承担 than on consumers. 买者支付的价格 Price buyers pay 卖者得到的价格 Price sellers receive
税收负担是如何划分的 So, how is the burden of the 为什么? Why? d? 税收负担更多地落在市 弹性是衡量当条件变得 场中缺乏弹性的一方 不利时,买者或卖者离 The burden of a tax 开市场的意愿 falls more heavily on 当征税时,不能轻而易 the side of the market 举离开市场的一方承担 that is less elastic 更多的税收负担。 举例:工薪税与社会保障 Payroll Tax and Social Security 举例:工薪税与社会保障 Payroll Tax and Social Security Labor ◆工薪税在雇员和企业之间的税收负担的 企忖的工 划分与法律规定的划分(比如平摊) 因为劳动的供给远比劳动的需求缺乏弹 ◆所以雇员而不是企业承担了大部分工薪 税的负担。 劈动量 Quan 举例:谁支付奢侈品税? 总结 Who Pays Taxes on Luxury Summary Goods? ◆价格控侧包括价格上限和价格下限 ◆对奢侈品征税似乎是向富人征税的有效 Price controls include price ceilings and price floors 方式。 ◆价格上限是某种物品戚服务价格的法定最高限。房租控 制是一例。 ◆但是,因为对某一奢侈品的需求极富弹 A price ceiling is a legal maximum on the price of a good 性,但供应在短期内缺乏弹性 or service. An example is rent controL ◆所以,税收负担主要落在生产者(企 ◆价格下限是某种物品或服务价格的法定最低限。最低工 资是一例 和工人)身上。 A price floor is a legal minimum on the price of a good ◆事与愿违:奢侈品税的负担落在穷人身 or a service. An example is the minimum wage. 上比富人身上要多。 41
7 37 税收负担是如何划分的？ So, how is the burden of the tax divided? 税收负担更多地落在市 场中缺乏弹性的一方 The burden of a tax falls more heavily on the side of the market that is less elastic. 38 为什么？ Why? 弹性是衡量当条件变得 不利时，买者或卖者离 开市场的意愿。 当征税时，不能轻而易 举离开市场的一方承担 更多的税收负担。 39 举例：工薪税与社会保障 Payroll Tax and Social Security 劳动量Quantity of Labor 0 工资Wage 没有税收的工 资Wage without tax Labor demand Labor supply 税收楔子 Tax wedge 企业支付的工 资Wage firms pay 工人得到的工资 Wage workers receive 40 举例：工薪税与社会保障 Payroll Tax and Social Security 工薪税在雇员和企业之间的税收负担的 划分与法律规定的划分（比如平摊）无 关。 因为劳动的供给远比劳动的需求缺乏弹 性。 所以雇员而不是企业承担了大部分工薪 税的负担。 41 举例：谁支付奢侈品税？ Who Pays Taxes on Luxury Goods? 对奢侈品征税似乎是向富人征税的有效 方式。 但是，因为对某一奢侈品的需求极富弹 性，但供应在短期内缺乏弹性。 所以，税收负担主要落在生产者（企业 和工人）身上。 事与愿违：奢侈品税的负担落在穷人身 上比富人身上要多。 42 总结 Summary 价格控制包括价格上限和价格下限。 Price controls include price ceilings and price floors. 价格上限是某种物品或服务价格的法定最高限。房租控 制是一例。 A price ceiling is a legal maximum on the price of a good or service. An example is rent control. 价格下限是某种物品或服务价格的法定最低限。最低工 资是一例。 A price floor is a legal minimum on the price of a good or a service. An example is the minimum wage
总结 总结 Summary Summary ◆税收负担指的是谁承担税负。 ◆税收用来为公共目的筹集资金。 The incidence of a tax refers to who bears the Taxes are used to raise revenue for public purposes. burden of a tax 当政府对一种物品征税收时,该物品的均衡数量减 ◆税收负担不取决于是向买者征税,还是向卖者 When the government levies a tax on a good, the 征税 equilibrium quantity of the good falls. The incidence of a tax does not depend on 税是在买者支付的价格和卖者支付的 whether the tax is levied on buvers or sellers. ◆税收负担取决于供给和需求的价格弹性 A tax on a good places a wedge paid by buyers and the price received by sellers The incidence of the tax depends on the price elasticities of supply and demand
8 43 总结 Summary 税收用来为公共目的筹集资金。 Taxes are used to raise revenue for public purposes. 当政府对一种物品征税收时，该物品的均衡数量减 少。 When the government levies a tax on a good, the equilibrium quantity of the good falls. 对一种物品征税是在买者支付的价格和卖者支付的 价格之间打入了一个楔子。 A tax on a good places a wedge between the price paid by buyers and the price received by sellers. 44 总结 Summary 税收负担指的是谁承担税负。 The incidence of a tax refers to who bears the burden of a tax. 税收负担不取决于是向买者征税，还是向卖者 征税。 The incidence of a tax does not depend on whether the tax is levied on buyers or sellers. 税收负担取决于供给和需求的价格弹性。 The incidence of the tax depends on the price elasticities of supply and demand