Questions for review
1.Explain how buyers’ willingness to pay, consumer surplus, and the demand curve are related. 需求曲线反映了买者的支付意愿。在任何一种数量时，需求曲线给出的价格表示边际买者的支付意愿。需求曲线一下和价格以上的总面积是一种物品或劳务市场上所有买者消费者剩余的总和。
2.Explain how llers’ costs, producer surplus, and the supply curve are related.
梨和白萝卜煮水有什么功效供给曲线的高度与卖者的成本相关。在任何一种数量时，供给曲线给出的价格表示边际卖者的成本。价格之下和供给曲线以上的面积衡量市场的生产者剩余。
3.In a supply-and-demand diagram, show producer and consumer surplus in the market
equilibrium.
电饼铛食谱大全APE的面积代表消费者剩余；
PBE的面积代表生产者剩余。
4.What is efficiency? Is it the only goal of economic policymakers?
效率是指资源配置使社会所有成员得到的总剩余最大化的性质。除了效率外，经济决策者还应该关心平等。实际上，市场交易的好处很像在市场参与者之间分割一块蛋糕，经济决策者不仅要关心如何将经济蛋糕做大，即效率；还要考虑如何在市场参与者之间分这块蛋糕，这就涉及公平问题。
5.What does the invisible hand do?
每一个市场参与者都会尽力追求自己的利益，看不见的手指引他们在相互竞争中达到一个并非他们本意想要达到的目的，这就是市场均衡点。在均衡点上，消费者剩余和生产者剩余总和最大化，整个社会福利达到最大。少女发型图片大全
6.Name two types of market failure. Explain why each may cau market outcomes to be
炖蛋的做法inefficient.
市场失灵包括市场势力和外部性。如果某一市场上存在市场势力，即只有极少部分（可能是一个）买者或卖者可以控制市场价格，他们就会使价格趋向于对他们这一小部分人有益的水平。于是，市场价格和数量背离供求平衡，社会福利达不到最大，市场失去效率。外部性是某些市场参与者的行为对旁观者福利的影响。它使市场福利还要取决于买者评价和卖者成本之外的其他因素。由于买者和卖者在决定消费和生产时并没有考虑这种负作用。所以，从整个社会角度来看，市场均衡可能是无效率的。
Problems and applications
1.An early freeze in California sours the lemon crop. What happens to consumer surplus in the
market for lemons? What happens to consumer surplus in the market for lemonade? Illustrate your answers with diagrams.
柠檬变酸，消费者对柠檬的评价下降，需求曲线向左下方移动。在其他条件不变的情况下，消费者剩余减少。如图7-2（a）所示，柠檬质量下降，使需求曲线从D1下降到D2，APE是原先的消费者剩余，A'P'E'是变动后的消费者剩余，ΔAPE>ΔA'P'E'。由于柠檬价格的下降，柠檬水的投入成本减少，柠檬水的价格也下降。在其他条件不变的情况下，柠檬水市场上消费者剩余增加，如图7-2（b）所示。
2.Suppo the demand for French bread ris. What happens to producer surplus in the market
for French bread? What happens to producer surplus in the market for flour? Illustrate your answer with diagrams.
由于需求增加，在其他条件不变的情况下，法国面包的价格会上升，市场上的生产者剩余增加。如图7-3（a），价格从P1上升的P2，销量从Q1上升到Q2，生产者剩余从面积P1BE1增加到面积P2BE2.
由于面包产量上升，它的生产要素面粉的需求量也会上升。在其他条件不变的情况下，面粉价格上升，市场上的生产者剩余增加。如图7-3（b）所示，生产者剩余从面积P1BE1增加到面积P2BE2.
3.It is a hot day, and Bert is thirsty. Here is the value he places on a bottle of water:
V alue of first bottle $7
V alue of cond bottle 5
V alue of third bottle 3
V alue of fourth bottle 1
a.From this information, drive Bert’s demand schedule. Graph his demand curve for bottled
water.
b.If the price of a bottle of water is $4, how many bottles does Bert buy? How much consumer
surplus does Bert get from his purchas? Show Bert’s consumer surplus in your graph.
c.If the price falls to $2, how does quantity demanded change? How does Bert’s consumer
surplus change? Show the changes in your graph.
Answer:
a. 表7-1 博特的需求表
所示，博特的消费者剩余是4美元（7-4+5-4=4）。
c. 如果价格下降到2美元，需求量增加到3，博特的消费者剩余增加到9美元。如图7-6所示，博特的消费者剩余增加到9美元（7-2+5-2+3-2=9）。
感冒喝什么汤
超级好听的歌曲
4.The cost of producing stereo systems has fallen over the past veral decades. Let’s consider
some implications of this fact.
a.U a supply-and-demand diagram to show the effect of falling production costs on the price
and quantity of stereos sold.
b.In your diagram, show what happens to consumer surplus and producer surplus.
c.Suppo the supply of stereos is very elastic. Who benefits most from falling production costs
—consumers or producers of stereos?
Answer:
a.
成本下降使供给曲线从S1向右下方移动到S2，立体声音响系统价格从P1下降到P2，销售量从Q1上升到Q2.
b.从图中可以看出，成本下降使消费者剩余增加，从面积AP1E1增加到面积AP2E2。生产
者剩余也增加了，从面积B1P1E增加到面积B2P2E2.
c.假定立体声音响系统的供给非常富有弹性，那么，消费者从生产成本下降中获益最大。
5.Suppo a technological advance reduces the cost of making computers.
a.U a supply-and-demand diagram to show what happens to price, quantity, consumer surplus,
and producer surplus in the market for computers.
b.Computers and adding machines are substitutes. U a supply-and-demand diagram to show
what happens to price, quantity, consumer surplus, and producer surplus in the market for adding machines. Should adding machine producers be happy or sad by the technological advance in computers?
c.Computers and software are complements. U a supply-and-demand diagram to show what
happens to price, quantity, consumer surplus, and producer surplus in the market for software.
Should software producers be happy or sad about the technological advance in computers? d.Does this analysis help explain why software producer Bill Gates is one of the world’s richest
men?
京东订单Answer:军训小结
a.
成本下降使供给曲线从S1向右下方移动到S2，电脑市场上价格从P1下降到P2，销售量从Q1上升到Q2.消费者剩余从面积AP1E1增加到AP2E2，生产者剩余从面积P1E1B1增加到P2E2B2.
b.
