再看市场均衡 消费者、生产者 Revisiting the Market Equilibrium 与市场效率 市场均衡价格和数量使买者和卖者的总福利 Consumers. Producers 最大化吗? and the Efficiency of Do the equilibrium price and quantity Markets maximize the total welfare of buyers and sellers? ◆市场均衡反映出市场配置希缺资源的方式 Market equilibrium reflects the way markets 第7章 allocate scarce resources Chapter 7 ◆市场的资源配量是否令人满意,取决于福利经济 Whether the market allocation is desirable is determined by welfare economies 福利经济学 Welfare economics 福利经济学 Welfare Economics 福利经济学研究资源配置如何影响经济福利。 are economics 市场均衡导致收益最大化,因此导致消 allocation of resourees affects economic well- 费者和生产者的总体福利的最大化。 ◆买者和实者从参与市场中收益。 Equilibrium in the market results in Buyers and sellers receive benefits from taking part in maximum benefits, and therefore maximum total welfare for both the ◆市场上供求均衡可以使买者和卖者的总福和最大化。 consumers and the producers of the The equilibrium in a market can maximize the tota welfare of buvers and sell roduct 福利经济学 消费者剩余 Welfare Economics Consumer Surplus ◆消费者剩余衡量买方的经济福利 ◆支付意愿是买者愿意且能够为某一物品 Consumer surplus measures economic 支付的最高价格。 welfare from the buyer's side willingness to pay is the maximum price ◆生产者剩余衡量卖方的经济福利 that a buyer is willing and able to pay for Producer surplus measures economic a good welfare from the seller's side ◆它衡量买者对物品或服务的评价是多少 It measures how much the buver values the good or service
1 1 消费者、生产者 与市场效率 Consumers, Producers, and the Efficiency of Markets 第7章 Chapter 7 2 再看市场均衡 Revisiting the Market Equilibrium 市场均衡价格和数量使买者和卖者的总福利 最大化吗? Do the equilibrium price and quantity maximize the total welfare of buyers and sellers? 市场均衡反映出市场配置稀缺资源的方式。 Market equilibrium reflects the way markets allocate scarce resources. 市场的资源配置是否令人满意，取决于福利经济 学。 Whether the market allocation is desirable is determined by welfare economics. 3 福利经济学 Welfare Economics 福利经济学研究资源配置如何影响经济福利。 Welfare economics is the study of how the allocation of resources affects economic wellbeing. 买者和卖者从参与市场中收益。 Buyers and sellers receive benefits from taking part in the market. 市场上供求均衡可以使买者和卖者的总福利最大化。 The equilibrium in a market can maximize the total welfare of buyers and sellers. 4 福利经济学 Welfare Economics 市场均衡导致收益最大化，因此导致消 费者和生产者的总体福利的最大化。 Equilibrium in the market results in maximum benefits, and therefore maximum total welfare for both the consumers and the producers of the product. 5 福利经济学 Welfare Economics 消费者剩余衡量买方的经济福利。 Consumer surplus measures economic welfare from the buyer’s side. 生产者剩余衡量卖方的经济福利。 Producer surplus measures economic welfare from the seller’s side. 6 消费者剩余 Consumer Surplus 支付意愿是买者愿意且能够为某一物品 支付的最高价格。 Willingness to pay is the maximum price that a buyer is willing and able to pay for a good. 它衡量买者对物品或服务的评价是多少 It measures how much the buyer values the good or service
消费者剩余 让我们来参加一场拍卖会 Consumer Surplus ◆拍卖品:外星人的经原课本1本 消费者剩余是买者的支付意愿减 ◆拍卖的参加者:John,Paul, George and 买者的实际支付额。 Consumer surplus is the amount a ◆拍卖规则:买者由低到高出价,每次加 buyer is willing to pay for a good 价以10美元为最小单位。出价最高者得 minus the amount the buyer 到这个课本,并支付其报价 actually pays for it. 褴得到课本,成交价是多少? 买者的支付意愿 Four Possible Buyers'willingness 让我们来参加一场拍卖会 to Pay. ◆John将得到课本,成交价为80(成90)美元。 买者 支付意愿 ◆John得到的消费者剩余(也是市场的总消费者 剩余)为: Willingness to Pay 100-80=20美元 John ◆假设有两本课本呢? ◆John和Pau将得到课本,成交价为70美元。 George 70 ◆John得到100-70=30美元的消费者剩余;Pau得到 80-70=10美元的消贵者剩余 Ringo ◆市场的总消费者剩余为30+10=40美 买者的四种可能的支付意尽 消费者剩余 Four Possible Buyers'Willingness Consumer Surplus to Pay 消费者剩余与一种物品的需求曲线密切相关 价格 需求量 Consumer surplus is closely related to the demand Quantity Price B Demanded curve for a product. 市场需求曲线画出了在不同的价格下,买者愿意 More than $100None 和能够购买的数量。 s80 to $10 The market demand curve depicts the various S70 to s80 John Paul quantities that buyers would be willing and able to purchase at different prices. S50 to S70 John, Paul, George ohn, Paul, George, Ring
2 7 消费者剩余 Consumer Surplus 消费者剩余是买者的支付意愿减 买者的实际支付额。 Consumer surplus is the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it. 8 让我们来参加一场拍卖会…… 拍卖品：外星人的经原课本1本 拍卖的参加者：John, Paul, George and Ringo. 拍卖规则：买者由低到高出价，每次加 价以10美元为最小单位。出价最高者得 到这个课本，并支付其报价。 谁得到课本，成交价是多少？ 9 买者的支付意愿 Four Possible Buyers’ Willingness to Pay... 买者 Buyer 支付意愿 Willingness to Pay John $100 Paul 80 George 70 Ringo 50 10 让我们来参加一场拍卖会…… John将得到课本，成交价为80（或90）美元。 John得到的消费者剩余（也是市场的总消费者 剩余）为： 100-80=20美元 假设有两本课本呢？ John和Paul将得到课本，成交价为70美元。 John得到100-70=30美元的消费者剩余；Paul得到 80-70=10美元的消费者剩余。 市场的总消费者剩余为30+10=40美元。 11 消费者剩余 Consumer Surplus 消费者剩余与一种物品的需求曲线密切相关。 Consumer surplus is closely related to the demand curve for a product. 市场需求曲线画出了在不同的价格下，买者愿意 和能够购买的数量。 The market demand curve depicts the various quantities that buyers would be willing and able to purchase at different prices. 12 买者的四种可能的支付意愿 Four Possible Buyers’ Willingness to Pay... 价格 Price 买者 Buyer 需求量 Quantity Demanded More than $100 None 0 $80 to $100 John 1 $70 to $80 John, Paul 2 $50 to $70 John, Paul, George 3 $50 or less John, Paul, George, Ringo 4
用需求曲线衡量消费者剩余 用雳求的线衡量消费者剩余 Measuring Consumer Surplus with Measuring Consumer Surplus with the demand curve the demand curve ◆在任何一种数量下,需求曲线给出的价格(需 车100 John的文付盒 m°w盟Ppay 实精是!湾需点曾克简弃的买若 Pa器毁利Y the price given by th curve shows the willingness to pay ofthe marginal buver, the buyer whowho would leave the market first if the price were any higher. 由于需求曲线反应了买者的支付意愿,我们可 需求 以用它衡量消费者剩余。 Because the demand curve reflects buyers' willingness to pay, we can also use it to measure consumer surplus 用雳求曲线衡量消费者剩余 用雳求的线衡量消费者剩余 Measuring Consumer Surplus with Measuring Consumer Surplus with the demand curve the demand cun 价格Prie=s0 价格Prce John的消我者剩余 John的者余 Johns consumer surplus($20) Paul's consumer surplus($10) 需求 Demand 012 Quantity of Quantity of Albums Is Albums 16 价格如何影响消费者剩余 用需求曲线衡量消费者剩余 How the price affects consumer Measuring Consumer Surplus with Surplus the demand curve 需求曲线以下和价格以上的面积衡 量市场的消费者剩余。 The area below the demand curve plus to new and above the price measures the consumer surplus in the market. 高求 Demand
3 13 用需求曲线衡量消费者剩余 Measuring Consumer Surplus with the Demand Curve... 价格 Price of Album 50 70 80 0 $100 1234 数量 Quantity of Albums John的支付意愿 John’s willingness to pay Paul的支付意愿 Paul’s willingness to pay George的支付意愿 George’s willingness to pay Ringo的支付意愿 Ringo’s willingness to pay 需求 Demand 14 用需求曲线衡量消费者剩余 Measuring Consumer Surplus with the Demand Curve... 在任何一种数量下，需求曲线给出的价格（需 求曲线的高度）表示边际买者的支付意愿；边际 买者是如果价格再高一点，就首先离开的买者。 At any quantity, the price given by the demand curve shows the willingness to pay of the marginal buyer, the buyer who who would leave the market first if the price were any higher. 由于需求曲线反应了买者的支付意愿，我们可 以用它衡量消费者剩余。Because the demand curve reflects buyers’ willingness to pay, we can also use it to measure consumer surplus. 15 用需求曲线衡量消费者剩余 Measuring Consumer Surplus with the Demand Curve... Price of Album 50 70 80 0 $100 1234 Quantity of Albums 需求 Demand John的消费者剩余 John’s consumer surplus ($20) 价格Price = $80 16 用需求曲线衡量消费者剩余 Measuring Consumer Surplus with the Demand Curve... Price of Album 50 70 80 0 $100 1234 Quantity of Albums Demand John的消费者剩余 John’s consumer surplus ($30) 总消费者剩余 Total consumer surplus ($40) 价格Price = $70 Paul的消费者剩余 Paul’s consumer surplus ($10) 17 用需求曲线衡量消费者剩余 Measuring Consumer Surplus with the Demand Curve 需求曲线以下和价格以上的面积衡 量市场的消费者剩余。 The area below the demand curve and above the price measures the consumer surplus in the market. Q2 P2 价格如何影响消费者剩余 How the Price Affects Consumer Surplus... 数量 Quantity 价格 Price 0 需求Demand 原来的消 费者剩余 Initial consumer surplus 原来消费者 的额外消费 者剩余 Additional consumer surplus to initial consumers 新消费者的消费者 剩余Consumer surplus to new consumers Q1 P1 D E F B C A
消费者剩余与经济福利 生产者剩余 Consumer Surplus and Economic Producer Surplus Well-Being 生产者剩余是卖者出售一种物品得到的 消费者剩余,即买者愿意为一种物品支付的金 金额减 卖者的成 本 额减他们实际支付的金额,衡量了消费者从 Producer surplus is the amount a seller is 种物品中得到的买者自己感觉到的收益 Consumer surplus, the amount that buyers are paid minus the cost of production. willing to pay for a good minus the amount they ◆它衡量了卖者参与市场得到的收益 actually pay for it, measures the benefit that It measures the benefit to sellers participating in a market themselves perceive it. 四个可能的卖者的成本 生产者剩余与供给曲线 The Costs of Four Possible Producer Surplus and the Sellers Supply Curve 实者Sele 成本cost ◆正如消费者剩余与需求曲线密切相关,生产者剩余也 与供绐曲线密切相关 Just as consumer surplus is related to the demand curve, producer surplus is closely related to the supply a 800 curvea ◆在任何一种数量上,供给曲线给出的价格表示边际卖 个边际卖者是如果价格再略低一点就首 Grandma 500 At any quantity, the price given by the supply curve ows the cost of the marginal seller, the seller who would leave the market first if the price were any 四个卖者的供给量 生产者剩余与供给曲线 Supply Schedule for the Four Producer Surplus and the Possible sellers Supply Curve. 价格 兴者 供给量 供给 Supply Price Sellers Supplied Mary,'s cost S900 or mo ary, Fnda, Georgia Grandma $800 to $900 Frida, Georgia, Grandma S600 to S800 Georgia, Grandma s500tos600 Less than s500 None 数 QUantity o Houses Painted
4 19 消费者剩余与经济福利 Consumer Surplus and Economic Well-Being 消费者剩余，即买者愿意为一种物品支付的金 额减他们实际支付的金额，衡量了消费者从一 种物品中得到的买者自己感觉到的收益。 Consumer surplus, the amount that buyers are willing to pay for a good minus the amount they actually pay for it, measures the benefit that buyers receive from a good as the buyers themselves perceive it. 20 生产者剩余 Producer Surplus 生产者剩余是卖者出售一种物品得到的 金额减去卖者的成本。 Producer surplus is the amount a seller is paid minus the cost of production. 它衡量了卖者参与市场得到的收益。 It measures the benefit to sellers participating in a market. 21 四个可能的卖者的成本 The Costs of Four Possible Sellers... 卖者 Seller 成本 Cost Mary $900 Frida 800 Georgia 600 Grandma 500 22 生产者剩余与供给曲线 Producer Surplus and the Supply Curve 正如消费者剩余与需求曲线密切相关，生产者剩余也 与供给曲线密切相关。 Just as consumer surplus is related to the demand curve, producer surplus is closely related to the supply curve. 在任何一种数量上，供给曲线给出的价格表示边际卖 者的成本，这个边际卖者是如果价格再略低一点就首 先离开市场的卖者。 At any quantity, the price given by the supply curve shows the cost of the marginal seller, the seller who would leave the market first if the price were any lower. 23 四个卖者的供给量 Supply Schedule for the Four Possible Sellers... 价格 Price 卖者 Sellers 供给量 Quantity Supplied $900 or more Mary, Frida, Georgia, Grandma 4 $800 to $900 Frida, Georgia, Grandma 3 $600 to $800 Georgia, Grandma 2 $500 to $600 Grandma 1 Less than $500 None 0 24 生产者剩余与供给曲线 Producer Surplus and the Supply Curve... 数量Quantity of Houses Painted 价格 Price of House Painting 500 800 $900 0 600 123 4 Grandma’s cost Georgia’s cost Frida’s cost Mary’s cost 供给Supply
用供给曲线衡量生产者剩余 生产者剩余与供给曲线 Measuring Producer Surplus with the Producer Surplus and the Supply Curve. Supply Curve 供给曲线以上和价格以下的面积衡 s900 量市场的生产者剩余。 The area below the price and above he supply curve measures th producer surplus in a market. lus (soo 用供给的线衡量生产者剩余 价格如何影响生产者剩余 Measuring Producer Surplus with the How Price Affects Producer Supply curve Surplu 价格 Price of 价格P Painting 原来生产膏 生产着剩余 Q 方场均德的评价 市场均衡时的消费者与生产者剩余 Evaluating the Market Equilibrium Consumer and Producer Surplus in the Market Equilibrium 均衡价格 tq始你格c 需求 Demand Quantity 均衡价格 数 qUantity
5 25 供给曲线以上和价格以下的面积衡 量市场的生产者剩余。 The area below the price and above the supply curve measures the producer surplus in a market. 生产者剩余与供给曲线 Producer Surplus and the Supply Curve 26 用供给曲线衡量生产者剩余 Measuring Producer Surplus with the Supply Curve... 数量Quantity of Houses Painted 价格Price of House Painting 500 800 $900 0 600 123 4 供给Supply Grandma的生产剩余 Grandma’s producer surplus ($100) 价格Price = $600 27 用供给曲线衡量生产者剩余 Measuring Producer Surplus with the Supply Curve... 数量Quantity of Houses Painted 价格Price of House Painting 500 800 $900 0 600 123 4 供给Supply Grandma的生产者剩余 Grandma’s producer surplus ($300) Price = $800 Georgia的生产者剩余 Georgia’s producer surplus ($200) 总生产者剩余 Total producer surplus ($500) 28 P2 Q2 价格如何影响生产者剩余 How Price Affects Producer Surplus... 数量Quantity 价格Price 0 供给Supply Q1 P1 A B 原来的生 C 产者剩余 Initial Producer surplus 原来生产者 的额外生产者剩余 Additional producer surplus to initial producers D E F 新生产者的生产者剩余 Producer surplus to new producers 29 市场均衡的评价 Evaluating the Market Equilibrium... 价格 Price 均衡价格 Equilibrium price 0 Quantity 均衡数量 Equilibrium quantity A 供给Supply C B 需求Demand D E 30 市场均衡时的消费者与生产者剩余 Consumer and Producer Surplus in the Market Equilibrium 价格 Price 均衡价格 Equilibrium price 0 均衡价格 数量Quantity Equilibrium quantity A 供给Supply C B 需求Demand D E 生产者剩余 Producer surplus 消费者剩余 Consumer surplus