经济学供给与需求市场与福利课件

路漫漫其悠远路漫漫其悠远2024/7/16经济学供给与需求市场经济学供给与需求市场与福利与福利路漫漫其悠远路漫漫其悠远Revisiting the Market EquilibriumDo the equilibrium price and quantity maximize the total welfare of buyers and sellers?uMarket equilibrium reflects the way markets allocate scarce resources.u Whether the market allocation is desirable is determined by welfare economics.路漫漫其悠远路漫漫其悠远回顾市场均衡回顾市场均衡市场均衡价格和数量能否使买者和市场均衡价格和数量能否使买者和卖者的总利益最大化？卖者的总利益最大化？u市场均衡反映了市场配置稀缺资源的方式。市场均衡反映了市场配置稀缺资源的方式。u 市场配置资源是否合意可以根据福利经济市场配置资源是否合意可以根据福利经济学理论判定。学理论判定。路漫漫其悠远路漫漫其悠远Welfare EconomicsWelfare economics is the study of how the allocation of resources affects economic well-being.福利经济学福利经济学研究资源配置如何影研究资源配置如何影响经济福利响经济福利。路漫漫其悠远路漫漫其悠远Welfare Economics 福利经济学福利经济学Equilibrium in the market results in maximum benefits,and therefore maximum total welfare for both the consumers and the producers of the product.市场均衡使利益最大化，即使产品的市场均衡使利益最大化，即使产品的消费者和生产者的总利益最大化。消费者和生产者的总利益最大化。路漫漫其悠远路漫漫其悠远Welfare Economics 福利经济学福利经济学uConsumer surplus measures economic welfare from the buyers side.消费者剩余从消费者角度衡量经济福利。消费者剩余从消费者角度衡量经济福利。uProducer surplus measures economic welfare from the sellers side.生产者剩余从生产者角度衡量经济福利。生产者剩余从生产者角度衡量经济福利。路漫漫其悠远路漫漫其悠远Consumer Surplus 消费者剩余消费者剩余uWillingness to pay is the maximum price that a buyer is willing and able to pay for a good.支付意愿支付意愿买者为某种物品愿意和能买者为某种物品愿意和能够支付的最高价格。够支付的最高价格。uIt measures how much the buyer values the good or service.它衡量买者对物品的评价是多少。它衡量买者对物品的评价是多少。路漫漫其悠远路漫漫其悠远Consumer Surplus 消费者剩余消费者剩余Consumer surplus is the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it.消费者剩余消费者剩余 买者支付意愿减去买者支付意愿减去买者的实际支付量。买者的实际支付量。路漫漫其悠远路漫漫其悠远Four Possible Buyers Willingness to Pay.四个可能买者的支付意愿四个可能买者的支付意愿路漫漫其悠远路漫漫其悠远Consumer Surplus 消费者剩余消费者剩余The market demand curve depicts the various quantities that buyers would be willing and able to purchase at different prices.市场需求曲线表示在不同价格水平市场需求曲线表示在不同价格水平下，买者愿意和能够购买的数量。下，买者愿意和能够购买的数量。路漫漫其悠远路漫漫其悠远The Demand Schedule and the Demand Curve路漫漫其悠远路漫漫其悠远需求表与需求曲线需求表与需求曲线路漫漫其悠远路漫漫其悠远Figure 1 The Demand Schedule and the Demand CurvePrice ofAlbum5070800$1001234Quantity ofAlbumsJohns willingness to payPauls willingness to payGeorges willingness to payRingos willingness to payDemand路漫漫其悠远路漫漫其悠远图图1.需求表与需求曲线需求表与需求曲线专辑的专辑的价格价格5070800$1001234专辑的数量专辑的数量约翰的支付意愿约翰的支付意愿保罗的支付意愿保罗的支付意愿乔治的支付意愿乔治的支付意愿林格的支付意愿林格的支付意愿需求需求路漫漫其悠远路漫漫其悠远Measuring Consumer Surplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsDemandJohns consumer surplus($20)Price=$80路漫漫其悠远路漫漫其悠远用需求曲线衡量消费者剩余用需求曲线衡量消费者剩余.专辑的专辑的价格价格5070800$1001234专辑的数量专辑的数量需求需求约翰的消费者剩余（约翰的消费者剩余（20美元）美元）价格价格=80美元美元Figure 2 Measuring Consumer Surplus with the Demand Curve(b)Price=$70Price ofAlbum5070800$100Demand1234Totalconsumersurplus($40)Quantity ofAlbumsJohns consumer surplus($30)Pauls consumersurplus($10)图图2.用需求曲线衡量消费者剩余用需求曲线衡量消费者剩余(b)价格价格=70美元美元专辑的专辑的价格价格5070800$100 需求1234总消费者剩余总消费者剩余(40美元美元)专辑的数量专辑的数量约翰的消费者剩余约翰的消费者剩余(30美元美元)保罗的消费者保罗的消费者剩余剩余(10美元美元)Figure 3 How the Price Affects Consumer SurplusConsumersurplusQuantity(a)Consumer Surplus at Price PPrice0DemandP1Q1BAC图图3.价格如何影响消费者剩余价格如何影响消费者剩余消费者剩余数量数量(a)价格在价格在P价格价格0需求P1Q1BAC时的消费者剩余时的消费者剩余Figure 3 How the Price Affects Consumer SurplusInitialconsumersurplusQuantity(b)Consumer Surplus at Price PPrice0DemandABCDEFP1Q1P2Q2Consumer surplusto new consumersAdditional consumersurplus to initial consumersQ2P2图图3.价格如何影响消费者剩余价格如何影响消费者剩余数量数量价格价格0需求需求原来的消原来的消费者剩余费者剩余原来消费者原来消费者新增的消费新增的消费者剩余者剩余新消费者的新消费者的消费者剩余消费者剩余Q1P1DEFBCA（b）价格在）价格在P2 时的消费者剩余时的消费者剩余路漫漫其悠远路漫漫其悠远Measuring Consumer Surplus with the Demand Curve用需求曲线衡量消费者剩余用需求曲线衡量消费者剩余The area below the demand curve and above the price measures the consumer surplus in the market.需求曲线以下和价格以上的面积衡需求曲线以下和价格以上的面积衡量市场的消费者剩余。量市场的消费者剩余。路漫漫其悠远路漫漫其悠远What Does Consumer Surplus Measure?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.路漫漫其悠远路漫漫其悠远消费者剩余衡量了什么？消费者剩余衡量了什么？消费者剩余，消费者剩余，即买者愿意为一种物即买者愿意为一种物品支付的量减他们实际支付的量，品支付的量减他们实际支付的量，衡量了消费者从一种物品中得到的衡量了消费者从一种物品中得到的买者自己感觉到的利益。买者自己感觉到的利益。路漫漫其悠远路漫漫其悠远Producer Surplus 生产者剩余生产者剩余uProducer surplus is the amount a seller is paid minus the sellers cost.生产者剩余生产者剩余卖者得到的量减去卖者的卖者得到的量减去卖者的成本。成本。uIt measures the benefit to sellers participating in a market.它衡量了卖者从参与市场中得到的利益。它衡量了卖者从参与市场中得到的利益。路漫漫其悠远路漫漫其悠远The Costs of Four Possible Sellers.四个可能卖者的成本四个可能卖者的成本路漫漫其悠远路漫漫其悠远Using the Supply Curve to Measure Producer Surplus利用供给曲线衡量生产者剩余利用供给曲线衡量生产者剩余uJust as consumer surplus is related to the demand curve,producer surplus is closely related to the supply curve.正如消费者剩余与需求曲线密切相关正如消费者剩余与需求曲线密切相关一样，生产者剩余也与供给曲线紧密一样，生产者剩余也与供给曲线紧密相关。相关。路漫漫其悠远路漫漫其悠远The Supply Schedule and the Supply Curve路漫漫其悠远路漫漫其悠远供给表和供给曲线供给表和供给曲线路漫漫其悠远路漫漫其悠远The Supply Schedule and the Supply Curve供给表和供给曲线供给表和供给曲线Quantity of Houses Painted要油漆的房子数量要油漆的房子数量Price of HousePainting油漆房子的价格油漆房子的价格500800$90006001234Grandmas cost格拉玛的成本格拉玛的成本Georgias cost 乔治亚的成本乔治亚的成本Fridas cost 路易斯的成本路易斯的成本 Marys cost 玛丽的成本玛丽的成本Supply 供给供给Figure 6 How the Price Affects Producer SurplusCopyright2003 Southwestern/Thomson LearningProducersurplusQuantity(a)Producer Surplus at Price P Price0SupplyBACQ1P1图图6.价格如何影响生产者剩余价格如何影响生产者剩余Copyright2003 Southwestern/Thomson Learning生产者剩余数量数量(a)价格在价格在 P 价格价格0供给BACQ1P1时的生产者剩余时的生产者剩余路漫漫其悠远路漫漫其悠远The area below the price and above the supply curve measures the producer surplus in a market.价格以下和供给曲线以上的面积衡价格以下和供给曲线以上的面积衡量市场的生产者剩余。量市场的生产者剩余。Using the Supply Curve to Measure Producer Surplus 用供给曲线衡量生产者剩余用供给曲线衡量生产者剩余路漫漫其悠远路漫漫其悠远MARKET EFFICIENCYandConsumer Surplus=Value to buyers_Amount paid by buyersProducer Surplus=Amount received by sellers_Cost to sellers路漫漫其悠远路漫漫其悠远市场效率市场效率和和消费者剩余消费者剩余=买者的评买者的评价价_买者支付的量买者支付的量生产者剩余生产者剩余=卖者得到的量卖者得到的量_卖者的卖者的成本成本路漫漫其悠远路漫漫其悠远MARKET EFFICIENCYorTotal Surplus=Value tobuyers_Cost to sellersTotal Surplus=Consumer SurplusProducer Surplus+路漫漫其悠远路漫漫其悠远市场市场 效率效率或或总剩余总剩余=买者的评买者的评价价_卖者的卖者的成本成本总剩余总剩余=消费者剩余消费者剩余生产者剩余生产者剩余+路漫漫其悠远路漫漫其悠远Market Efficiency 市场效率市场效率Market efficiency is the property of a resource allocation of maximizing the total surplus received by all members of society.市场效率市场效率资源配置使社会所有资源配置使社会所有成员得到的总剩余最大化的性质。成员得到的总剩余最大化的性质。路漫漫其悠远路漫漫其悠远Market Efficiency 市场效率市场效率In addition to market efficiency,a social planner might also care about equity the fairness of the distribution of well-being among the various buyers and sellers.除了效率之外，社会计划者还应关心除了效率之外，社会计划者还应关心平等平等福利在各种买者与卖者之间福利在各种买者与卖者之间分配的公平性。分配的公平性。路漫漫其悠远路漫漫其悠远Consumer and Producer Surplus in the Market Equilibrium.PriceEquilibriumprice0QuantityEquilibriumquantityASupplyCBDemandDEProducersurplusConsumersurplus路漫漫其悠远路漫漫其悠远市场均衡时的消费者与生产者剩余市场均衡时的消费者与生产者剩余.价格价格均衡价格均衡价格0数量数量均衡数量均衡数量A供给供给CB需求需求DE生产者剩余生产者剩余消费者剩余消费者剩余路漫漫其悠远路漫漫其悠远SummaryuConsumer surplus equals buyers willingness to pay for a good minus the amount they actually pay for it.uConsumer surplus measures the benefit buyers get from participating in a market.uConsumer surplus can be computed by finding the area below the demand curve and above the price.路漫漫其悠远路漫漫其悠远小结小结u消费者剩余等于买者对某种物品的支消费者剩余等于买者对某种物品的支付意愿减去买者的实际支付量。付意愿减去买者的实际支付量。u消费者剩余衡量买者从参与市场中得消费者剩余衡量买者从参与市场中得到的利益到的利益u消费者剩余可以通过找出需求曲线以消费者剩余可以通过找出需求曲线以下和价格以上的面积来计算。下和价格以上的面积来计算。路漫漫其悠远路漫漫其悠远SummaryuProducer surplus equals the amount sellers receive for their goods minus their costs of production.uProducer surplus measures the benefit sellers get from participating in a market.uProducer surplus can be computed by finding the area below the price and above the supply curve.路漫漫其悠远路漫漫其悠远小结小结u生产者剩余等于卖者出售某种物品得到生产者剩余等于卖者出售某种物品得到的量减去卖者的生产成本。的量减去卖者的生产成本。u生产者剩余衡量买者从参与市场中得到生产者剩余衡量买者从参与市场中得到的利益的利益u生产者剩余可以通过找出价格以下和供生产者剩余可以通过找出价格以下和供给曲线以上的面积来计算。给曲线以上的面积来计算。路漫漫其悠远路漫漫其悠远SummaryuAn allocation of resources that maximizes the sum of consumer and producer surplus is said to be efficient.uPolicymakers are often concerned with the efficiency,as well as the equity,of economic outcomes.