微观经济学原理 ch

1、Questions for review1. What happens to consumer and producer surplus when the sale of a good is taxed? How does the change in consumer and producer surplus compare to the tax revenue? Explain.当对一种物品征税时，消费者和生产者剩余都会减少。我们可以用税收前后的总福利来比较生产者剩余和消费者剩余变动与税收收入，看税收前的福利与税收后的福利谁大谁小。税收前的福利=生产者剩余+消费者剩余，税收后的福利=生产者剩

2、余+消费者剩余+税收收入。税收前的福利大于税收后的福利，说明生产者剩余和消费者剩余的减少大于税收收入。反之，则小于。2. Draw a supply-and-demand diagram with a tax on the sale of the good. Show the deadweight loss. Show the tax revenue.如图8-1所示，对一种物品征税减少了消费者剩余（面积B+E表示减少量）和生产者剩余（面积C+F表示减少量）。生产者和消费者剩余的减少大于税收收入（用面积B+C表示），税收引起了无谓损失（用面积E+F表示）。3. How do the elasti

3、cities of supply and demand affect the deadweight loss of a tax? Why do they have this effect?供给与需求曲线的弹性越大，税收的无谓损失越大；供给与需求曲线的弹性越小，税收的无谓损失越小。因为供给和需求弹性衡量买者和卖者对价格变动的反应程度，决定了税收扭曲会使市场结果有多大变动。4. What happens to the deadweight loss and tax revenue when a tax is increased?当税收增加时，无谓损失增加，并且无谓损失的增加要快于税收规模的增加。税

4、收增加时，税收收入先增加，然后随着税收规模越来越大，市场收缩非常之大，以至于税收收入开始减少。Problems and applications1. Evaluate the following two statements. Do you agree? Why or why not?a. “If the government taxes land, wealthy landowners will pass the tax on to their poorer renters.”b. “If the government taxes apartment buildings, wealthy l

5、andlords will pass the tax on to their poorer renters.”Answer:a. 同意。因为佃户对土地的需求基本是无弹性的，而税收总是市场中弹性较小的一方承担的多。所以，地主可以把税收转嫁给贫穷的佃户。b. 部分同意。在短期内，对于公寓楼的需求基本是缺乏弹性的，因为寻找新住处需要一定时间。此时，房东会通过提高房租或减少对房屋的维修投入将税收转嫁给房客。但是，对公寓楼的需求在长期中是较富有弹性的，房客可以去选择更廉价的住处。因此，房东和房客将分担这项税收。2. Evaluate the following two statements. Do yo

6、u agree? Why or why not?a. “A tax that has no deadweight loss cannot raise any revenue for the government.”b. “A tax that raises no revenue for the government cannot have any deadweight loss.”Answer:a. 不同意。有些税收不会产生无谓损失，只会增加政府收入。例如庇古税，它是用于纠正负外部性的税收。征收庇古税使资源配置接近于社会最优，既增加了政府收入，又提高了经济福利。b. 不同意。除极个别情况外，税

7、收都会引起市场规模的缩小，造成无谓损失。如果政府对某种物品的销售额全额征税，这个市场的需求和供给就会变成零，此时政府没有税收收入，但却带来极大的无谓损失，这个市场的买者和卖者无法进行互利的贸易了。3. After economics class one day, your friend suggests that taxing food would be a good way to raise revenue because the demand for food is quite inelastic. In what sense is taxing food a “good” way to

8、raise revenue? In what sense is it not a “good” way to raise revenue?从理论上说，对食物征税是增加税收的“好”方法。首先，食物的需求是完全无弹性的，人必须吃饱肚子，食物买者承担了全部税负。其次，税收的无谓损失取决于供给和需求的弹性。食物的需求完全无弹性，食物税不会改变市场配置，没有无谓损失。政府的税收收入等于消费者的损失。但从实际中看，为了使食物税没有扭曲经济激励，必须是对没有经过加工的、最基本最原始的食物征税。但是食物各种各样，它们的价值取决于其营养、口感、卫生状况、精细程度等等。因此，食物的需求实际上是有弹性的。对食物征税

9、，会使消费者倾向于选择粗劣的、低廉的食物。扭曲了对市场的激励，有无谓损失的存在。4. Most states tax the purchase of new cars. Suppose that New Jersey currently requires car dealers to pay the state $100 for each car sold, and plans to increase the tax to $150 per car next year.a. Illustrate the effect of this tax increase on the quantity o

10、f cars sold in New Jersey, the price paid by consumers, and the price received by producers.b. Create a table that shows the levels of consumer surplus, producer surplus, government revenue, and total surplus both before and after the tax increase.c. What is the change in government revenue? Is it p

11、ositive or negative?d. What is the change in deadweight loss? Is it positive or negative?e. Give one reason why the demand for cars in New Jersey might be fairly elastic. Does this make the additional tax more or less likely to increase government revenue? How might states try to reduce the elastici

12、ty of demand?Answer:a. 这种税收使新泽西汽车销售量下降，消费品支付的价格上升，生产者得到的价格下降。b. 表8-1 税收增加前后的福利变动表100美元税收时150美元税收时变动消费者剩余A+B+CA(B+C)生产者剩余J+K+LL(J+K)政府收入D+E+G+HB+D+G+JB+J-E-H总剩余A+B+C+D+E+G+H+J+K+LA+B+D+G+J+L(C+E+H+K)c. 政府收入变动，是正是负还需要考察这种税收规模使新泽西州的汽车市场处在拉伐曲线的哪一边。如果150美元/辆的税使市场处在拉伐曲线不利的一边，则政府收入变动为负；如果150美元/辆的税收下，市场仍处在拉

13、伐曲线有利的一边，则政府收入变动为正。d. 无谓损失增加。税收增加会使市场规模进一步减小，产生更大的无谓损失。e. 我设想，新泽西因为收入水平较低，使汽车需求相当富有弹性。在这种情况下，价格上升就会有许多人退出市场，市场规模随税收的增加而收缩的很快，无谓损失太大，税收收入负增长。该州应增加对居民购买汽车的补贴，使需求弹性减小。5. This chapter analyzed the welfare effects of a tax on a good. Consider now the opposite policy. Suppose that the government subsidize

14、s a good: For each unit of the good sold, the government pays $2 to the buyer. How does the subsidy affect consumer surplus, producer surplus, tax revenue, and total surplus? Does a subsidy lead to a deadweight loss? Explain.政府向买者支付的补贴使消费者剩余增加，生产者剩余不变，因为补贴降低了买者的价格，消费者购买意愿会增加，市场销量增加，从而政府税收收入增加，总剩余增加。

15、补贴也会引起无谓损失。因为当补贴的对象是消费者不是生产者时，这种产品的市场规模会超出最优规模，使更多的资源集中用于生产这种物品，造成资源的无效配置。6. Suppose that a market is described by the following supply and demand equations: QS=2P QD=300-Pa. Solve for the equilibrium price and the equilibrium quantity.b. Suppose that a tax of T is placed on buyers, so the new deman

16、d equation is QD=300-(P+T)Solve for the new equilibrium. What happens to the price received by sellers, the price paid by buyers, and the quantity sold?c. Tax revenue is T×Q. Use your answer to part (b) to solve for tax revenue as a function of T. Graph this relationship for T between 0 and 300

17、.d. The deadweight loss of a tax is the area of the triangle between the supply and demand curves. Recalling that the area of a triangle is 1/2×base×height, solve for deadweight loss as a function of T between 0 and 300.e. The government now levies a tax on this good of $200 per unit. Is this a good policy? W