曼昆经济学原理英文课件Chap07.ppt

1、Consumers, Producers, and the Efficiency of MarketsChapter 7Copyright 2001 by Harcourt, Inc.All rights reserved. Requests for permission to make copies of any part of thework should be mailed to:Permissions Department, Harcourt College Publishers,6277 Sea Harbor Drive, Orlando, Florida 32887-6777.Ha

2、rcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.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 desi

3、rable is determined by welfare economics.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Welfare EconomicsWelfare economics is the study of how the allocation of resources affects economic well-being.uBuyers and sellers receive benefits from taking part in the market. uThe equ

4、ilibrium in a market maximizes the total welfare of buyers and sellers. Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Welfare EconomicsEquilibrium in the market results in maximum benefits, and therefore maximum total welfare for both the consumers and the producers of the p

5、roduct.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Welfare EconomicsuConsumer surplus measures economic welfare from the buyers side.uProducer surplus measures economic welfare from the sellers side.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Con

6、sumer SurplusuWillingness to pay is the maximum price that a buyer is willing and able to pay for a good.uIt measures how much the buyer values the good or service.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Consumer SurplusConsumer surplus is the amount a buyer is willing

7、 to pay for a good minus the amount the buyer actually pays for it.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Four Possible Buyers Willingness to Pay.BuyerWillingness to PayJohn$100Paul80George70Ringo50Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc

8、.Consumer SurplusThe market demand curve depicts the various quantities that buyers would be willing and able to purchase at different prices.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Four Possible Buyers Willingness to Pay.PriceBuyerQuantityDemandedMore than $100None0$8

9、0 to $100John1$70 to $80John, Paul2$50 to $70John, Paul, George3$50 or lessRingo4Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Consumer Surplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsJohns willingness to payPauls willingness to payGeorge

10、s willingness to payRingos willingness to payDemandHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Consumer Surplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsDemandJohns consumer surplus ($20)Price = $80Harcourt, Inc. items and derived items

11、copyright 2001 by Harcourt, Inc.Measuring Consumer Surplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsDemandJohns consumer surplus ($30)Total consumer surplus ($40)Price = $70Pauls consumer surplus ($10)Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Me

12、asuring Consumer Surplus with the Demand CurveThe area below the demand curve and above the price measures the consumer surplus in the market.Q2P2How the Price Affects Consumer Surplus.QuantityPrice0DemandCopyright 2001 by Harcourt, Inc. All rights reservedInitialconsumersurplusAdditional consumer s

13、urplus to initial consumersConsumer surplus to new consumersQ1P1DEFBCAHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Consumer Surplus and Economic Well-BeingConsumer surplus, the amount that buyers are willing to pay for a good minus the amount they actually pay for it, measu

14、res the benefit that buyers receive from a good as the buyers themselves perceive it.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Producer SurplusuProducer surplus is the amount a seller is paid minus the cost of production. uIt measures the benefit to sellers participating

15、 in a market.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Costs of Four Possible Sellers.SellerCostMary$900Frida800Georgia600Grandma500Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Producer Surplus and the Supply CurveuJust as consumer surplus i

16、s related to the demand curve, producer surplus is closely related to the supply curve.uAt 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.Harcourt, Inc. items and derived items copyright

17、 2001 by Harcourt, Inc.Supply Schedule for the Four Possible Sellers.PriceSellersQuantitySupplied$900 or moreMary, Frida, Georgia,Grandma4$800 to $900Frida, Georgia, Grandma3$600 to $800Georgia, Grandma2$500 to $600Grandma1Less than $500None0Harcourt, Inc. items and derived items copyright 2001 by H

18、arcourt, Inc.Producer Surplus and the Supply Curve.Quantity ofHouses PaintedPrice ofHousePainting500800$90006001234Grandmas costGeorgias costFridas costMarys costSupplyHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The area below the price and above the supply curve measures

19、the producer surplus in a market.Producer Surplus and the Supply CurveHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Producer Surplus with the Supply Curve.Quantity ofHouses PaintedPrice ofHousePainting500800$90006001234SupplyGrandmas producersurplus ($100)Price = $

20、600Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Producer Surplus with the Supply Curve.Quantity ofHouses PaintedPrice ofHousePainting500800$90006001234SupplyGrandmas producersurplus ($300)Price = $800Georgias producersurplus ($200)Totalproducersurplus ($500)Harcou

21、rt, Inc. items and derived items copyright 2001 by Harcourt, Inc.P2Q2How Price Affects Producer Surplus.QuantityPrice0SupplyQ1P1ABCInitial ProducersurplusAdditional producersurplus to initialproducersDEFProducer surplusto new producersHarcourt, Inc. items and derived items copyright 2001 by Harcourt

22、, Inc.Market EfficiencyConsumer surplus and producer surplus may be used to address the following question:Is the allocation of resources determined by free markets in any way desirable?Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Economic Well-Being and Total SurplusandCon

23、sumer Surplus=Value to buyers_Amount paid by buyersProducer Surplus=Amount received by sellers_Cost to sellersHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Economic Well-Being and Total SurplusorTotal Surplus=Value tobuyers_Cost to sellersTotal Surplus=Consumer SurplusProduc

24、er Surplus+Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Market EfficiencyMarket efficiency is achieved when the allocation of resources maximizes total surplus.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Market EfficiencyIn addition to market effi

25、ciency, a social planner might also care about equity the fairness of the distribution of well-being among the various buyers and sellers.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Evaluating the Market Equilibrium.PriceEquilibriumprice0QuantityEquilibriumquantityASupplyC

26、BDemandDEHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Consumer and Producer Surplus in the Market Equilibrium.PriceEquilibriumprice0QuantityEquilibriumquantityASupplyCBDemandDEProducersurplusConsumersurplusHarcourt, Inc. items and derived items copyright 2001 by Harcourt, I

27、nc.Three Insights Concerning Market OutcomesuFree markets allocate the supply of goods to the buyers who value them most highly.uFree markets allocate the demand for goods to the sellers who can produce them at least cost.uFree markets produce the quantity of goods that maximizes the sum of consumer

28、 and producer surplus.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Price0QuantityEquilibriumquantitySupplyDemandCost to sellersValue to buyersValue to buyers Cost to sellersValue to buyers is greater than cost to sellers.Value to buyers is less than cost to sellers.The Effi

29、ciency of the Equilibrium QuantityHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Efficiency of the Equilibrium QuantityuBecause the equilibrium outcome is an efficient allocation of resources, the social planner can leave the market outcome as he/she finds it. uThis polic

30、y of leaving well enough alone goes by the French expression laissez faire.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Market PoweruIf a market system is not perfectly competitive, market power may result.uMarket power is the ability to influence prices.uMarket power can c

31、ause markets to be inefficient because it keeps price and quantity from the equilibrium of supply and demand.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.ExternalitiesExternalities are created when a market outcome affects individuals other than buyers and sellers in that m

32、arket.uExternalities cause welfare in a market todepend on more than just the value to the buyers and cost to the sellers.uWhen buyers and sellers do not take externalities into account when deciding how much to consume and produce, the equilibrium in the market can be inefficient.Harcourt, Inc. ite

33、ms and derived items copyright 2001 by Harcourt, Inc.SummaryuConsumer 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.Harcourt, Inc. items and derived items copyright 2001 by Harco

34、urt, Inc.SummaryuProducer 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.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.SummaryuThe equilibrium of demand

35、and supply maximizes the sum of consumer and producer surplus.uThis is as if the invisible hand of the marketplace leads buyers and sellers to allocate resources efficiently.uMarkets do not allocate resources efficiently in the presence of market failures.Harcourt, Inc. items and derived items copyr

36、ight 2001 by Harcourt, Inc.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.Harcourt, Inc. items and derived items copyright 2001 by Ha

37、rcourt, Inc.Graphical ReviewHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Consumer Surplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsJohns willingness to payPauls willingness to payGeorges willingness to payRingos willingness to payDemandHa

38、rcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Consumer Surplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsDemandJohns consumer surplus ($20)Price = $80Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Consumer Su

39、rplus with the Demand Curve.Price ofAlbum5070800$1001234Quantity ofAlbumsDemandJohns consumer surplus ($30)Total consumer surplus ($40)Price = $70Pauls consumer surplus ($10)How the Price Affects Consumer Surplus.Q2P2QuantityPrice0DemandCopyright 2001 by Harcourt, Inc. All rights reservedInitialcons

40、umersurplusAdditional consumer surplus to initial consumersConsumer surplus to new consumersQ1P1BCADEFHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Producer Surplus and the Supply Curve.Quantity ofHouses PaintedPrice ofHousePainting500800$90006001234Grandmas costGeorgias cos

41、tFridas costMarys costSupplyHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Measuring Producer Surplus with the Supply Curve.Quantity ofHouses PaintedPrice ofHousePainting500800$90006001234SupplyGrandmas producersurplus ($100)Price = $600Harcourt, Inc. items and derived items

42、copyright 2001 by Harcourt, Inc.Measuring Producer Surplus with the Supply Curve.Quantity ofHouses PaintedPrice ofHousePainting500800$90006001234SupplyGrandmas producersurplus ($300)Price = $800Georgias producersurplus ($200)Totalproducersurplus ($500)Harcourt, Inc. items and derived items copyright

43、 2001 by Harcourt, Inc.How Price Affects Producer Surplus.P2Q2QuantityPrice0SupplyQ1P1ABCInitial ProducersurplusAdditional producersurplus to initialproducersDEFProducer surplusto new producersHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Evaluating the Market Equilibrium.Pr

44、iceEquilibriumprice0QuantityEquilibriumquantityASupplyCBDemandDEHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Consumer and Producer Surplus in the Market Equilibrium.PriceEquilibriumprice0QuantityEquilibriumquantityASupplyCBDemandDEProducersurplusConsumersurplusHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Price0QuantityEquilibriumquantitySupplyDemandCost to sellersValue to buyersValue to buyersCost to sellersValue to buyers is greater than cost to sellers.Value to buyers is less than cost to sellers.The Efficiency of the Equilibrium Quantity