1、曼昆微观经济学课后练习英文答案rketsWHATS NEW IN THE SIXTH EDITION:There are no major changes to this chapter.LEARNING OBJECTIVES:By the end of this chapter, students should understand: the link between buyers willingness to pay for a good and the demand curve. how to define and measure consumer surplus. the link b
2、etween sellers costs of producing a good and the supply curve. how to define and measure producer surplus. that the equilibrium of supply and demand maximizes total surplus in a market.CONTEXT AND PURPOSE:Chapter 7 is the first chapter in a three-chapter sequence on welfare economics and market effi
3、ciency. Chapter 7 employs the supply and demand model to develop consumer surplus and producer surplus as a measure of welfare and market efficiency. These concepts are then utilized in Chapters 8 and 9 to determine the winners and losers from taxation and restrictions on international trade. The pu
4、rpose of Chapter 7 is to develop welfare economicsthe study of how the allocation of resources affects economic well-being. Chapters 4 through 6 employed supply and demand in a positive framework, which focused on the question, “What is the equilibrium price and quantity in a market?” This chapter n
5、ow addresses the normative question, “Is the equilibrium price and quantity in a market the best possible solution to the resource allocation problem, or is it simply the price and quantity that balance supply and demand?” Students will discover that under most circumstances the equilibrium price an
6、d quantity is also the one that maximizes welfare.KEY POINTS:? Consumer surplus equals buyers willingness to pay for a good minus the amount they actually pay for it, and it measures the benefit buyers get from participating in a market. Consumer surplus can be computed by finding the area below the
7、 demand curve and above the price.? Producer surplus equals the amount sellers receive for their goods minus their costs of production, and it measures the benefit sellers get from participating in a market. Producer surplus can be computed by finding the area below the price and above the supply cu
8、rve.? An allocation of resources that maximizes the sum of consumer and producer surplus is said to be efficient. Policymakers are often concerned with the efficiency, as well as the equality, of economic outcomes.? The equilibrium of supply and demand maximizes the sum of consumer and producer surp
9、lus. That is, the invisible hand of the marketplace leads buyers and sellers to allocate resources efficiently.? Markets do not allocate resources efficiently in the presence of market failures such as market power or externalities.CHAPTER OUTLINE:I. Definition of welfare economics: the study of how
10、 the allocation of resources affects economic well-being.II. Consumer SurplusA. Willingness to Pay1. Definition of willingness to pay: the maximum amount that a buyer will pay for a good.2. Example: You are auctioning a mint-condition recording of Elvis Presleys first album. Four buyers show up. The
11、ir willingness to pay is as follows:BuyerWillingness to PayJohn$100Paul$80George$70Ringo$50If the bidding goes to slightly higher than $80, all buyers drop out except for John. Because John is willing to pay more than he has to for the album, he derives some benefit from participating in the market.
12、3. Definition of consumer surplus: the amount a buyer is willing to pay for a good minus the amount the buyer actually pays for it.4. Note that if you had more than one copy of the album, the price in the auction would end up being lower (a little over $70 in the case of two albums) and both John an
13、d Paul would gain consumer surplus.B. Using the Demand Curve to Measure Consumer Surplus1. We can use the information on willingness to pay to derive a demand curve for the rare Elvis Presley album.PriceBuyersQuantity DemandedMore than $100None0$80 to $100John1$70 to $80John, Paul2$50 to $70John, Pa
14、ul, George3$50 or lessJohn, Paul, George, Ringo4Figure 12. At any given quantity, the price given by the demand curve reflects the willingness to pay of the marginal buyer. Because the demand curve shows the buyers willingness to pay, we can use the demand curve to measure consumer surplus.Figure 23
15、. Consumer surplus can be measured as the area below the demand curve and above the price.C. How a Lower Price Raises Consumer SurplusFigure 31. As price falls, consumer surplus increases for two reasons.a. Those already buying the product will receive additional consumer surplus because they are pa
16、ying less for the product than before (area A on the graph).b. Because the price is now lower, some new buyers will enter the market and receive consumer surplus on these additional units of output purchased (area B on the graph).D. What Does Consumer Surplus Measure?It is important to stress that c
17、onsumer surplus is measured in monetary terms. Consumer surplus gives us a way to place a monetary cost on inefficient market outcomes (due to government involvement or market failure).1. Remember that consumer surplus is the difference between the amount that buyers are willing to pay for a good an
18、d the price that they actually pay. 2. Thus, it measures the benefit that consumers receive from the good as the buyers themselves perceive it.ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price ceilings from Chapter 6. Redraw the market for two-bedroom apartments in your town. Draw in a pric
19、e ceiling below the equilibrium price. Then go through: consumer surplus before the price ceiling is put into place. consumer surplus after the price ceiling is put into place.III. Producer SurplusA. Cost and the Willingness to Sell1. Definition of cost: the value of everything a seller must give up
20、 to produce a good.You will need to take some time to explain the relationship between the producers willingness to sell and the cost of producing the good. The relationship between cost and the supply curve is not as apparent as the relationship between the demand curve and willingness to pay.2. Ex
21、ample: You want to hire someone to paint your house. You accept bids for the work from four sellers. Each painter is willing to work if the price you will pay exceeds her opportunity cost. (Note that this opportunity cost thus represents willingness to sell.) The costs are:SellerCostMary$900Frida$80
22、0Georgia$600Grandma$500Table 23. Bidding will stop when the price gets to be slightly below $600. All sellers will drop out except for Grandma. Because Grandma receives more than she would require to paint the house, she derives some benefit from producing in the market.4. Definition of producer sur
23、plus: the amount a seller is paid for a good minus the sellers cost of providing it.5. Note that if you had more than one house to paint, the price in the auction would end up being higher (a little under $800 in the case of two houses) and both Grandma and Georgia would gain producer surplus.B. Usi
24、ng the Supply Curve to Measure Producer Surplus1. We can use the information on cost (willingness to sell) to derive a supply curve for house painting services.PriceSellersQuantity Supplied$900 or moreMary, Frida, Georgia, Grandma4$800 to $900Frida, Georgia, Grandma3$600 to $800Georgia, Grandma2$500
25、 to $600Grandma1less than $500None02. At any given quantity, the price given by the supply curve represents the cost of the marginal seller. Because the supply curve shows the sellers cost (willingness to sell), we can use the supply curve to measure producer surplus.3. Producer surplus can be measu
26、red as the area above the supply curve and below the price.C. How a Higher Price Raises Producer SurplusFigure 61. As price rises, producer surplus increases for two reasons.a. Those already selling the product will receive additional producer surplus because they are receiving more for the product
27、than before (area C on the graph).b. Because the price is now higher, some new sellers will enter the market and receive producer surplus on these additional units of output sold (area D on the graph).ALTERNATIVE CLASSROOM EXAMPLE:Review the material on price floors from Chapter 6. Redraw the market
28、 for an agricultural product such as corn. Draw in a price support above the equilibrium price. Then go through: producer surplus before the price support is put in place. producer surplus after the price support is put in place. Make sure that you discuss the cost of the price support to taxpayers.
29、D. Producer surplus is used to measure the economic well-being of producers, much like consumer surplus is used to measure the economic well-being of consumers.Pretty Woman, Chapter 6. Vivien (Julia Roberts) and Edward (Richard Gere) negotiate a price. Afterward, Vivien reveals she would have accept
30、ed a lower price, while Edward admits he would have paid more. If you have done a good job of introducing consumer and producer surplus, you will see the light bulbs go off above your students heads as they watch this clip.IV. Market EfficiencyA. The Benevolent Social Planner1. The economic well-bei
31、ng of everyone in society can be measured by total surplus, which is the sum of consumer surplus and producer surplus:Total Surplus = Consumer Surplus + Producer SurplusTotal Surplus = (Value to Buyers Amount Paid by Buyers) + (Amount Received by Sellers Cost to Sellers)Because the Amount Paid by Bu
32、yers = Amount Received by Sellers:2. Definition of efficiency: the property of a resource allocation of maximizing the total surplus received by all members of society.3. Definition of equality: the property of distributing economic prosperity uniformly the members of society.B. Evaluating the Market Equilibrium1. At the market equilibrium price:a. Buy
