第七版答案(翻译-英译中结果)

曼昆《经济学原理》第七版课后习题的答案（中文版）!!30曼昆《经济学原理》第七版课后习题的答案（中文版）！！练习题1、任何一个所得税表都体现了两种税率——平均税率和边际税率。

（题中的表见课本12章）a、平均税率定义为支付的总税收除以收入。

对表12—7中的比例税制来说，赚5万美元、10万美元和20万美元的人，其平均税率分别是多少？在累退税制和累进税制中相对应的平均税率是多少？答：从表12—7中很容易看出，赚5万美元、10万美元和20万美元的人，其平均税率都是25%。

在累退税制中，赚5万美元、10万美元和20万美元的人，其平均税率分别是30%，25%，20%。

在累进税制中，赚5万美元、10万美元和20万美元的人，其平均税率分别是20%，25%，30%。

b、边际税率定义为额外收入支付的税收除以增加的额外收入。

计算比例税制下，收入从5万美元增加到10万美元的边际税率。

计算收入从10万美元增加到20万美元的边际税率。

计算累退税制和累进税制下相对应的边际税率答：（1）比例税制。

当收入从5万美元增加到10万美元时，税收量增加了1.25万，因此边际税率为1.25/5=0.25，即25%。

当收入从10万美元增加到20万美元时，税收量增加了2.5万，因此边际税率为2.5/10=0.25，即25%。

（2）累退税制。

当收入从5万美元增加到10万美元时，税收量增加了1万，因此边际税率为1/5=0.2，即20%。

当收入从10万美元增加到20万美元时，税收量增加了1.5万，因此边际税率为1.5/10=0.15，即15%。

（3）累进税制。

当收入从5万美元增加到10万美元时，税收量增加了1.5万，因此边际税率为1.5/5=0.3，即30%。

当收入从10万美元增加到20万美元时，税收量增加了3.5万，因此边际税率为3.5/10=0.35，即35%。

c、描述这三种税制中每一种的平均税率和边际税率之间的关系。

一般来说，某人在决定是否接受工资比目前工作略高一点的工作时，哪一种税率更适用？在判断税制的纵向平等时，哪一种税率更适用？答：在比例税制下，平均税率和边际税率相等，且都不随收入变动而变动。

第七版世纪英语综合教程课文翻译Unit1问候的礼节1.中国人认为用正确的方式与人打招呼是非常重要的。

他们遵循自谦、尊重他人的原则向对方表达一种敬意。

2.中国人过去通常在胸前双手抱拳行见面礼。

下级、学生或侍从用鞠躬来向上级表达敬意。

但现在，除了在春节，中国人已不再打躬作揖。

当今，年轻人只以点头作为招呼。

这在某种程度上反映了现代生活节奏的日益加快。

3.称谓能反映社会中人们之间的关系。

在正式场合，对年长者和位高者直呼其名是非常不好且粗鲁的。

应该根据他们的头衔来称呼他们。

中国人习惯用“头衔+姓氏”来称呼上司和长辈，而不是叫他们的姓。

对较亲近的人，他们往往不用像“你不高兴？””或“你看起来很憔悴”这样的用语，这被认为不合适。

在中国商界，见到陌生人通常要交换名片。

名片要双手递给对方。

4.在讲英语的国家，人们不管年龄和地位，往往直呼其名，除了称呼医生以外，（这样）不是想引起不悦，而是要表示一种亲近感。

对称谓有疑问时，就按正式礼节称呼，因为严守礼节而出点差错总比不礼貌要好一点。

5.中国人觉得对西方人直呼其名不太自然，感觉那样关系太亲近。

而另一方面，西方人觉得如果中国人坚持用姓氏来称呼，则表示中国人不愿意太亲近，想保持一定的距离。

所以，“怀特小姐”、“格林先生”这些称谓也许是中国人的一种折衷方式。

Unit2大学生活1.倘若一生是一幅色彩斑斓的画卷，那么大学生活一定是那浓墨重彩的一笔。

倘若一生是一首含义深刻的诗篇，那么大学生活一定是那最为清丽的语句。

大学的确是一个非比寻常的黄金时期，利用得好，你学到的不只是课内的理论，还可以掌握课外的实际知识。

2.从你成为大学生的那一刻起，你就要拥抱全新生活，你就要开始自立自强。

不光要适应新的环境，还要学会一切靠自己，自立自强。

3.大学就是一个缩小版的社会。

同在一片蓝天下，我们都要学会与人交往。

可是社交并不比其它技艺容易学。

如果你总能对他人面带微笑，别人也会愿意在必要时伸出援助之手。

英译汉短文翻译1. Job security is extremely hard to come by these days, no matter what profession you choose. It isn't enough to pursue a field with perceived stability, say the experts. You'll want to find something you feel passionate about, can make a living doing and that involves using skills you can easily apply to other fields.在当前的经济形势下，无论你从事何种职业，就业稳定都很难找到稳定的就业机会。

专家们表示，光是追求预计能够带来稳定就业的领域是不够的。

你希望追求的方向应该是你所热爱的、能够借以维持生计的职业，并且能够运用到一些你可以轻松转换到其它领域的技能。

2. Love plays a pivotal role on out life. Love makes you feel wanted. Without love a person could go hayward and also become cruel and ferocious. In the early stage of our life, our parents are the ones who shower us with unconditional love and care, they teach us about what is right and wrong, good and bad. But we always tend to take this for granted. It is only after marriage and having kids that a person understands and becomes sensitive to others feelings. Kids make a person responsible and mature and help us to understand life better.爱在生活之外扮演了一个关键的角色。

商务英语视听说答案第七版1、There _______ some milk in the glass. [单选题] *A. is(正确答案)B. areC. haveD. has2、Just use this room for the time being ,and we’ll offer you a larger one _______it becomes available [单选题] *A. as soon as(正确答案)B unless .C as far asD until3、31．A key ring is used __________ holding the keys. [单选题] *A．toB．inC．for (正确答案)D．with4、John Smith is _______ of the three young men. [单选题] *A. strongB. strongerC. the strongerD. the strongest(正确答案)5、If you get _______, you can have some bread on the table. [单选题] *A. happyB. hungry(正确答案)C. worriedD. sad6、You should _______ your card. [单选题] *A. drawB. depositC. investD. insert(正确答案)7、With all the work on hand, he _____ to the cinema last night. [单选题] *A.should goB.must have goneC.might goD..shouldn’t have gone(正确答案)8、The organization came into being in 1 [单选题] *A. 开始策划B. 进行改组C. 解散D. 成立于(正确答案)9、While they were in discussion, their manager came in by chance. [单选题] *A. 抓住时机B. 不时地C. 碰巧(正确答案)D. 及时10、Comparatively speaking, of the three civil servants, the girl with long hair is _____. [单选题] *A. more helpfulB. extremely helpfulC. very helpfulD. the most helpful(正确答案)11、____ father is a worker. [单选题] *A.Mike's and Mary'sB. Mike and Mary's(正确答案)C. Mike's and MaryD. Mike and Marys'12、Jim will _______ New York at 12 o’clock. [单选题] *A. get onB. get outC. get offD. get to(正确答案)13、English is very important in our daily life. Never _______. [单选题] *A. give up itB. give it up(正确答案)C. give away itD. give it away14、This seat is vacant and you can take it. [单选题] *A. 干净的B. 没人的(正确答案)C. 舒适的D. 前排的15、—Judging from ____ number of bikes, there are not many people in the party.—I think so. People would rather stay at home in such _____ weather. [单选题] *A. the, aB. a, /C. the, /(正确答案)D. a, a16、Tom will _______ me a gift from Japan. [单选题] *A. takeB. getC. carryD. bring(正确答案)17、These apples smell _____ and taste ______. [单选题] *A. well; wellB. good; good(正确答案)C. well; goodD. good; well18、—John, How is it going? —______.（）[单选题] *A. It’s sunnyB. Thank youC. Well doneD. Not bad(正确答案)19、4．—Alice’s never late for school.—________. [单选题] *A．So am I.B．So was I.C．Neither am I. (正确答案)D．Neither have I.20、Nobody noticed the thief slip into the shop, because the lights happened to _______. [单选题] *A. put outB. turn outC. give outD. go out(正确答案)21、If you don’t feel well, you’d better ask a ______ for help. [单选题] *A. policemanB. driverC. pilotD. doctor(正确答案)22、——Can you come on Monday or Tuesday? ——Im afraid（）of them is possible. [单选题] *A.neither(正确答案)B. eitherC. noneD.both23、The（)majority of the members were against the idea. [单选题] *A. substantialB. enormousC. considerable(正确答案)D. overwhelming24、He was proud of what he had done. [单选题] *A. 对…感到自豪(正确答案)B. 对…感到满足C. 对…表示不满D. 对…表示后悔25、Becky is having a great time ______ her aunt in Shanghai. （）[单选题] *A. to visitB. visitedC. visitsD. visiting(正确答案)26、She’s _______ with her present _______ job. [单选题] *A. boring; boringB. bored; boredC. boring; boredD. bored; boring(正确答案)27、Whatever difficulties you have, you should not _______ your hope. [单选题] *A. give inB. give outC. give up(正确答案)D. give back28、There may be something wrong with her _______. She can’t see things clearly. [单选题] *A. eyes(正确答案)B. earsC. mouthD. nose29、If by any chance someone comes to see me, ask him to leave a _____. [单选题] *A. message(正确答案)B. letterC. sentenceD. notice30、I’d?like _______ the English club. [单选题] *A. to join inB. joinC. to join(正确答案)D. join in。

中考英语翻译-英汉互译专题(含解析)中考英语翻译-英汉互译（含解析）(后附详细答案)(绝对精品试题，提高实战能力，值得下载打印背诵)一、翻译1.翻译下列句子（1）XXX needs to________（改变他的生活方式）now.（2）Do they need to buy ________（两千克胡萝卜）?（3）The hair clip________（和我的粉色外套搭配）. I'll take it.（4）I want to buy some presents________（和XXX的不同）.（5）She always walks a long way to school, so she________（最需要一双鞋）.（6）They visit houses and ________（和里面的人玩游戏）.（7）________（欣赏满月）is not much fun for children.（8）The jeans look quite nice. May I________（试穿一下）?（9）Some dogs just do n’t know ________（如何取乐）.（10）Apple juice________（尝起来好）.2.我明白了，你是—名老师。

________ ________．XXX．3.根据汉语提示，用句末括号内的英语单词完成句子。

（1）昨天XXX上学迟到了。

XXX ________ XXX.(be)（2）XXX因病住院了，他的女儿正在照顾他。

XXX and now his daughter ________ him. (take)（3）很多废弃物能变成像纸一样的材料。

Many waste things ________ a paper-like material.(turn)（4）我只好告诉你真相，那位作家已经把大部分钱捐给了慈善组织。

I have to tell you the truth, the writer ________ most of his money to XXX.(give)（5）科学家呼吁全球多关注气候变化和濒危动物的保护。

初一英语翻译试题答案及解析1.英汉互译（1＇ⅹ15）【1】用英语_____________【答案】in English【解析】“用……语言”的用是in，不是with.【2】电话号码_________________【答案】telephone(phone) number【解析】电话telephone和phone都可以。

【3】姓氏__________________【答案】last/ family name【解析】姓氏可以说成family name, last name, 还可以说成surname。

【4】中学 _____________【答案】middle school【解析】middle表示“中等的”“中间的”。

【5】电脑游戏______________【答案】computer game【解析】可以用单数，也可以复数。

Computer games.【6】我的书_________________【答案】my book(s)【解析】“我的”是形容词性的物主代词my，“书”可以单数，也可以复数。

【7】学生证_________________【答案】school ID card【解析】ID card是“身份证”。

加上school即是学生证。

【8】ask…for…_______________【答案】向某人要……【解析】ask的后面接人，即“向某人要求”，for的后面接所要求的物。

【9】a set of keys________________【答案】一串钥匙【解析】a set of是“一套……，一串……”。

【10】excuse me ____________【答案】对不起，劳驾，打搅一下【解析】excuse me 在要麻烦、打搅别人之前说的“对不起，请原谅”。

【11】Thank you for…___________________【答案】因……而感谢你【解析】for…的后面是要感谢的事情。

【12】You are welcome!_________________【答案】不用谢，没关系【解析】You are welcome!回答“谢谢”的答语。

1. He wanted to learn, to know, to teach.【译文】他想学习，增长知识，也愿意把自己所学教给别人。

2. She is young enough to get married.【译文】她还年轻，可以结婚。

3. From there I could see the whole valley below, the fields, the river, and the village. It was all very beautiful, and the sight of it filled me with longing. (N.S. Momaday: The End of My Childhood)【译文一】从那里，我可以看见下面的整个山谷，那田野、河流和村庄。

这一切非常美丽，见到后使我心里充满了渴望。

【译文二】从此望去，整个山谷一览无遗，田野、河流和村庄，美不胜收，使我心驰神往。

4〃We have 365 days in a year.【译文】一年365天。

5〃He stood up straight with arms folded, and laughed at the cap hanging there on the pole.【译文】他交臂直立，笑看帽子挂在杆子上那个样子。

6〃Our son must go to school. He must break out of the pot that holds us in.【译文】我们的儿子一定要上学，一定要出人头地。

7〃Is the press a great power in your country?【译文】贵国新闻界有很大的影响（力）吗？8〃Brown may say what he likes, but it is his wife who wears the trousers.【译文】布朗爱说什么就说什么，但当家作主的却是他老婆。

计算机专业英语教程第七版课后答案1、Could you please ______ why you can’t come to attend the meeting? [单选题] *A. explain(正确答案)B. understandC. giveD. reach2、———Must I return the book you lent me to you now? ——No, you( ）. You can keep it for another few days. [单选题] *A.can’tB. shouldn'tC. mustn'tD. don, t have to(正确答案)3、This species has nearly （）because its habitat is being destroyed. [单选题] *A. used upB. died out(正确答案)C. gone upD. got rid of4、He always found it hard to satisfy himself. [单选题] *A. 控制B. 满足(正确答案)C. 了解D. 批评5、18．Who is staying at home now? ________, all of them are out. [单选题] *A．NoneB．No one(正确答案)C．EveryoneD．Nothing6、Both Mary and Linda don't care for fish. [单选题] *A. 喜欢(正确答案)B. 关心C. 照料D. 在乎7、My father and I often go ______ on weekends so I can ______ very well. （）[单选题] *A. swim; swimmingB. swims; swimC. swimming; swimmingD. swimming; swim(正确答案)8、Why don’t you _______ the bad habit of smoking. [单选题] *A. apply forB. get rid of(正确答案)C. work asD. graduate from9、July hardly joins in any class activities,_____? [单选题] *A. does she(正确答案)B. doesn't sheC. didn't sheD. is she10、34．My mother usually_______ much time shopping in the supermarkets on weekends. [单选题] *A．spends (正确答案)B．costsC．takesD．pays11、You _____ smoke in the library, or you will be driven away. [单选题] *A. can'tB. mustn't(正确答案)C. will notD. may not12、While studying abroad, he financially depended（）his wife. [单选题] *A. on(正确答案)B. ofC. toD. from13、94．—Let’s go out for a picnic on Sunday.—________. [单选题] * A．Nice to meet youB．Here you areC．The same to youD．Good idea(正确答案)14、1．I saw ________ action film with my friend yesterday, and ________ film was amazing. [单选题] *A．a...aB．a...theC．an...the(正确答案)D．an...a15、Tomorrow is Ann’s birthday. Her mother is going to make a _______ meal for her. [单选题] *A. commonB. quickC. special(正确答案)D. simple16、He has made a lot of films, but ____ good ones. [单选题] *A. anyB. someC. few(正确答案)D. many17、Sorry, I can't accept your invitation. [单选题] *A. 礼物B. 观点C. 邀请(正确答案)D. 好意18、--Do you often go to the cinema _______ Sunday?--No, we _______. [单选题] *A. on; don’t(正确答案)B. on; aren’tC. in; doD. in; don’t19、The manager demanded that all employees _____ on time. [单选题] *A. be(正确答案)B. areC. to beD. would be20、Will you see to（）that the flowers are well protected during the rainy season? [单选题] *A. it(正确答案)B. meC. oneD. yourself21、39．—What do you ________ my new dress?—Very beautiful. [单选题] *A．look atB．think aboutC．think of(正确答案)D．look through22、I don’t know how to improve my English. Can I ask you for some _______? [单选题] *A. answersB. advice(正确答案)C. questionsD. words23、Guilin is _______ its beautiful scenery. [单选题] *A. famous for(正确答案)B. interested inC. fond ofD. careful with24、Mom, I need you ______ me a pencil box.（）[单选题] *A. buyB. buyingC. to buy(正确答案)D. to buying25、The family will have _______ good time in Shanghai Disneyland. [单选题] *A. theB. a(正确答案)C. anD. /26、You should take the medicine after you read the _______. [单选题] *A. linesB. wordsC. instructions(正确答案)D. suggestions27、The idea of working abroad really（）me. [单选题] *appeals to (正确答案)B. attaches toC. adapts toD. gets across28、Mrs. Black is on her way to England. She will _______ in London on Sunday afternoon. [单选题] *A. reachB. attendC. arrive(正确答案)D. get29、My friend and classmate Selina（)running in her spare time. [单选题] *A.likeB. likes (正确答案)C. is likedD. is liking30、_______ your help, I passed the English exam. [单选题] *A. ThanksB. Thanks to(正确答案)C. Thank youD. Thank to。

Chapter 7 – Income Redistribution: Conceptual Issues1. Utilitarianism suggests that social welfare is a function of individuals’ utilities. Whetherthe rich are vulgar is irrelevant, so this part of the statement is inconsistent with utilitarianism. O n the other hand, Stein’s assertion that inequality per se is unimportant is inconsistent with utilitarianism.2. a. To maximize W, set marginal utilities equal; the constraint is I s + I c = 100.So,400 - 2I s = 400 - 6I c.substituting I c = 100 - I s gives us 2I s = 6 (100 - I s ).Therefore, I s = 75, I c = 25.b.If only Charity matters, then give money to Charity until MU c = 0 (unless all themoney in the economy is exhausted first).So,400-6 I c = 0; hence, I c = 66.67.Giving any more money to Charity causes her marginal utility to become negative,which is not optimal. Note that we don’t care if the remaining money ($33.33) isgiven to Simon or not.If only Simon matters, then, proceeding as above, MU s. 0 if I s = 100; hence, givingall the money to Simon is optimal. (In fact, we would like to give him up to $200.)c.MU s = MU c for all levels of income. Hence, society is indifferent among alldistributions of income.3. The main conceptual problem with the poverty gap is that it doesn’t account fo r theincome effect on labor force participation rates. The poverty gap is calculated assuming there are no behavioral responses; e.g., that labor income would remain unchanged even after the income was transferred to the poor population, but economic theory predicts that this will not be so. In fact, if the poor household were given enough income to bring it out of poverty, we would believe that the household would work less as a result of receiving this transfer. This complicates the analysis, of course, because once the household works less, then it will generate less labor income, thus lowering its overall income. This means that the poverty gap actually understates the amount of money necessary to alleviate poverty in the United States. In addition, the poverty gap is based on the official poverty line, which is thought to be an ad-hoc measure of the true “needs”of a family.4. A day care center is an example of an in-kind compensation. The figure below is similarto Figure 8.2 in the text. The original budget line is G1 H1 If the employee received $5,000 cash, the budget line moves to G2 H2 . An employee who uses the day care center may not be $5,000 better off. The employee consumes at point A, but would be better off at point B, which represents consumption after a cash transfer of $5,000.5. a. This would increase the incomes of the providers of computer equipment and theindividuals who maintain the equipment. In the long run, this might also increasethe incomes of the students who use the equipment. Moreover, giving a laptop toall seventh graders (rather than poor seventh graders) may simply “crowd-out”computer transfers from parents to children. One could imagine that nowadaysmany children do have a computer at home, paid for by the parents. Thisgovernment transfer may simply result in less parental transfer to the child.b.Providing free after-school programs for children in impoverished families largelyacts as an in-kind transfer for poor, working households. The program is of littlevalue for unemployed households, as the alternative would be childcare at home.For those who are employed, and paying for childcare, this program provides analternative and effectively changes the after-tax, after-working-cost wage. Thisalso may affect work behavior on the extensive margin. The likely “losers” fromsuch a program are childcare providers, who see a reduction in demand for theirservices. In principle, this reduction in demand could lower the hourly childcarecost for all workers with children, though this effect is likely to be modest becausemost impoverished families do not have a very large labor force attachment and,thus, their effect on the childcare market as a whole is likely to be small.6. a. False. Society is indifferent between a util to each individual, not a dollar to eachindividual. Imagine that U L=I and U J=2I. Then each dollar given to Jonathanraises welfare more than the same dollar given to Lynne.b. True. The social welfare function assumes a cardinal interpretation of utility sothat comparisons across people are valid.c. False. Departures from complete equality raise social welfare to the extent thatthey raise the welfare of the person with the minimum level of utility. Forexample, with the utility functions U L=I and U J=2I, the social welfare functionW=min[U L,U J] would allocate twice as much income to Lynne than Jonathan.7. Initially the price of food was $2 and the price of other goods was $1. The black marketfor food stamps changes the price of food sold to $1. In Figure 7.2 of the textbook, as one moves to the “northwest” from point F, the segment will now have a slope (in absolute value) of 1 rather than 2. The black market may make the individual better off if the best point on her budget constraint AFD was initially at the corner solution of point F, and the black market certainly does not make her worse off. It is important to note that the black market does not always make the recipient better off. If the (absolute value) of the marginal rate of substitution (MRS) were between 1 and 2, the indifference curve would not “cut” into the new part of the budget constraint with the black market.If the MRS were less than (or equal to) 1 in absolute value, the person would be made better off and would reduce food consumption by selling the food stamps on the black market.Food StampGuarantee Food8. Pareto efficient redistribution is a reallocation of income that increases (or does notdecrease) the utility of all consumers. With these two consumers, Marsha’s utility increases as Sherry’s utility increases. Thus, it may be possible to reallocate income from Marsha to Sherry and raise both of their utility. With Sherry’s initial utility function of U S=100Y S1/2, her utility with $100 of income is U S=100($100)1/2, or U S=1,000. With Marsha’s initial utility function of U M=100Y M1/2+0.8U S, her utility with $100 of income is U M=100($100)1/2+0.8(1,000), or U M=1,800. If the social welfare function is additive, then initial welfare is W=U S+U M=1,000+1,800=2,800. If $36 is reallocated from Marsha to Sherry, then Sherry’s income is now $136 and Marsha’s is now $64. With Sherry’s utility function, her utility with $136 of income is U S=100($136)1/2, or U S=1,166.190.With Marsha’s utility function, her utility with $64 of income is U M=100($64)1/2+0.8(1,166.190), or U M=800+932.952=1,732.952. In this case, Sherry’s utility increases from 1,000 to 1,166.190, while Marsha’s utility falls from 1,800 to 1,732.952. Social welfare increases with this redistribution, going from 2,800 to 2,899.142. Thus, this redistribution increases social welfare, but is not Pareto efficient redistribution.Chapter 8 – Expenditure Programs for the Poor1. a. Note that the figure below shows the correct shape of the budget constraint, butthe numbers themselves are outdated. With a wage rate of $10 per hour,Elizabeth earns $100. Because the deduction in California is $225, none of herearnings are counted against the $645 welfare benefit. Thus, her total income is$745 (=$100+$645).b.The actual welfare benefits collected by a person equals B=G-t(Earnings-D),where B=actual benefits, G=welfare grant, t=tax rate on earned income, andD=standard deduction. Thus, (Earnings-D) is the net earnings that are taxed awayin the form of reduced benefits. When benefits equal zero (B=0), the expressionbecomes 0=G-t(Earnings-D), which collapses to: Earnings=G/t+D. This is knownas the “breakeven formula.” In the California context here, the expressionbecomes Earnings=$645/0.5 + 225, or Earnings=$1,515. With a wage rate of $10per hour, this corresponds to 151.5 hours of work per month.c.The diagram shows the correct shape of the budget constraint, but the “577” figureshould be r eplaced with “645” and the “9” hours should be replaced with “22.5”.d.The diagram above shows one possibility – in this case, Elizabeth is both workingand on welfare – but she collects a reduced welfare benefit in this case.2. One could gather data on the earnings of those in the program, as well as earnings datafrom nonparticipants. Regress the earnings variable on demographic variables and other factors that determine earnings (such as education and experience), and a variable that indicates whether the individual participated in the training program. Factors that affect local employment conditions, such as unemployment levels, may help explain earnings, but they may also explain participation in the program. The econometric strategy should be chosen carefully to account for this.3. If the quantity of leisure consumed by X appears as an argument in the utility function ofY, then X’s consumption of leisure creates an externality. If the externality is negative(i.e., Y likes X to work), then a wage subsidy of X might induce him to work the efficientnumber of hours. Alternatively, a workfare program might achieve the same goal by simply forcing X to work. However, to the extent that the feasible quantity of labor supply is determined less through market incentives now, workfare would be less efficient.4. He participates in the public housing program as long as P1P2ca cef.5. As illustrated below, the budget constraint with food stamps has a “notch” in it, similar tothe analysis of Medicaid in Figure 8.9 of the textbook. At the notch, the marginal tax rate is greater than 100%. One key difference from the figure in the textbook is that the marginal tax rate on earned income for Medicaid is 0% until the “Medicaid notch,” while the marginal tax rate on earned income for food stamps is 24% until the “food stamp notch.” The reason the food stamp notch exists at all is that there is a “gross income test,” where a recipient is ineligible if income is higher than the limit. The characterization in the Rosen textbook on page 189 that “at some point near the poverty line, food stamps worth about $1,250 are suddenly lost” implicitly assumes that childcare costs are quite high. This is likely to be true for many households. In the year 2004, this monthly (annual) gross income limit was $1,994 per month ($23,928 per year) for a family of four, while the monthly guarantee was $471 ($5,652 per year). Assuming the family had earnings at the limit of $1,994 of earnings during the month, and after applying a 20% earnings deduction and a $134 monthly standard deduction, the household would receive a monthly (annual) benefit of $32 ($384). We arrive at this number using the equation B=G-t(E-.2E-D)=471-.3(.8*1994-134)=$471-$438.36=$32.64, which is then rounded down to $32. In this case, B=actual benefits received, G=food stamp guarantee, t=tax rate, E=earnings, and D=standard deduction. Increasing annualearnings by $1 from $23,928 to $23,929 would reduce food stamp benefits from $384 to $0; hence the “food stamp notch.” This notch would be even higher if the household qualified for a childcare deduction, child support deduction, or shelter deduction. The childcare deduction ranges between $175 and $200 per child per month. Assuming this family of four consisted of a mother and three children, each with $175 of monthly childcare costs, then B=G-t(E-.2E-D-C)=471-.3(.8*1994-134-525)=$471-$280.86=$190.14, which is then rounded down to $190. The modification here is that C=childcare costs. This amount corresponds to an annual food stamp benefit of $2,280. Figure 8.5 below draws the budget constraint using annual levels for the food stamp program, using 2004 rules and assumes no childcare expenses.6. For an individual who is not working while on welfare, in this case the highestindifference curve touches the budget constraint on the right vertical axis. Note that the marginal rate of substitution (MRS) does not necessarily equal the after-tax wage rate at the time endowment – rather, it is possible that the person would want to consume more leisure than the time endowment but is obviously constrained from doing so.Leisure$23,928Leisure7.In all cases, the demand curve for housing slopes downward. a. If the price of low income housing gets bid up but there is no increase in the stock of housing, then the supply curve is perfectly inelastic, e.g., vertical.Q 0Q HOUSINGFIGURE 8.7a – Demand curve shiftsb.If there is no increase in the price of housing, but there is an increase in the stockof housing, then the supply curve is perfectly elastic, e.g., horizontal.Q 0Q HOUSINGFIGURE 8.7b – Demand curve shifts Q 1c.If there is an increase in both the price and quantity of housing, then the supplycurve slopes upward.According to Sinai and Waldfogel, there is partial crowding out, consistent with case cabove. Although the underlying housing stock itself is probably quite inelastic in the short-run, the number of rental homes can be more elastic as (potential) landlords convert vacation homes or vacant homes into rental units.8. a.When Eleanor’s hours (earnings) go from 0 to 1,000 ($0 to $8,000), she qualifiesfor an additional earned income tax credit (EITC) worth $3,200 (=0.4*8,000).Thus, her income goes up from $0 to $11,200. Note to instructors – thedistinction between earnings and income may cause confusion in the students’answers. b.When Eleanor’s hours (earnings) go from 1,000 to 1,500 ($8,000 to $12,000), shequalifies for the maximum EITC (according to Figure 8.8 in the textbook). Shereceives the full EITC when her earnings exceed $10,510, at which time the creditequals $4,204 (=0.4*$10,510). The earnings between $10,510 and $12,000 face neither a subsidy nor phase-out from the EITC. Thus, her income goes up from $11,200 to $16,204.c. When Eleanor’s hours (earnings) go from 1,500 to 2,000 ($12,000 to $16,000),she moves into the range where the EITC is phased out. According to Figure 8.8 Q 0Q HOUSINGFIGURE 8.7c – Demand curve shifts outward,Q 1in the textbook, she receives the maximum subsidy of $4,204 until her earningsexceed $14,730. For the marginal earnings between $14,730 and $16,000, theEITC is reduced at a 21.06% tax rate. Thus, her EITC falls by $267.46 from$4,204 to $3,936.54 (=4,204-0.2106*(16,000-14,730)). Her income rises from$16,204 to $19,936.54.Chapter 9 – Social Insurance I: Social Security and Unemployment Insurance1. With adverse selection, insurance contracts with more comprehensive coverage arechosen by people with higher unobserved accident probabilities. To make up for the fact that a benefit is more likely to be paid to such individuals, the insurer charges a higher premium per unit of insurance coverage.2. There are many possible implications of a voluntary Social Security system. Onepossibility is that people would save less for retirement, betting that society would not put up with having great numbers of elderly poor. Part of the effect of the Friedman program, then, would depend on the government's credibility when it promises not to bail out people who do not save enough to survive during retirement.3. Use the basic formula for balance in a pay-as-you-go social security system:t =(N b/N w)*(B/w).Call 1990 year 1 and 2050 year 2. Thent1 = .267*(B/w)1t2 = .458*(B/w)2It follows that to keep (B/w)1=(B/w)2 we require t2/t1=.458/.267=1.71. That is, tax rates would have to increase by 71 percent. Similarly, to keep the initial tax rate constant, we would require (B/w)2/(B/w)1=.267/.458=0.58. Benefits would have to fall almost by half.4. If Social Security benefits are partially taxed for those who have other income over acertain level, then there is an implicit means test in receiving full, untaxed benefits.However, there is no explicit means test for eligibility for the program. Everyone receives benefits, though some recipients must pay some tax on them. Thus, the two statements are somewhat inconsistent with each other.5. Austen’s quote seems like it could relate adverse selection, but perhaps more likely, tomoral hazard. The q uote “If you observe, people always live forever when there is any annuity to be paid them” in a sense sounds like they act differently (e.g., better diet, more exercise, etc.) when an annuity is to be paid –the idea of moral hazard. In contrast, adverse selection suggests that people who expect to live a long time to be the ones who purchase annuities. A recent paper by Finkelstein and Poterba (NBER working paper, December 2000) found that “mortality patterns are consistent with models of asymmetric inf ormation” and that annuity “insurance markets may be characterized by adverse selection.”6. Equation (9.1) relates taxes paid into the Social Security system to the dependency ratioand the replacement ratio, that is, t=(N b/ N w)*(B/w). If the goal of public policy is to maintain a constant level of benefits, B, rather than a constant replacement ratio, (B/w), then taxes may not need to be raised. If there is wage growth (through productivity), then it is possible to maintain B at a constant level, even if the dependency ratio is growing.By rearranging the equation, we can see that B=t*w*(N b/ N w)-1. That is, increases in wage rates (the second term) offset increases in the dependency ratio (the third term).Thus, constant benefits do not necessarily imply higher tax rates.7. The statement about how the different rates of return in the stock market and governmentbond market affect the solvency of the trust fund is false. If the trust fund buys stocks, someone else has to buy the government bonds that it was holding. So, there is no new saving and no new capacity to take care of future retirees.8. Diamond and Gruber’s calculations suggest that the additional year of work (and delayedretirement) lowers the present discounted value of expected Social Security wealth by $4,833. If the adjustment were actuarially fair, Social Security wealth would neither rise nor fall. Since wealth falls, the adjustment is actuarially unfair.9. For those who argue that the scheme for financing Social Security is unfair becausepeople with low earnings are taxed at a higher rate than those with high earnings, the key issue is that the cumulative payroll tax of 12.4 percent is capped for each person, after which the payroll tax is zero (this ignores the 2.9 percent uncapped Medicare tax, however). The earnings ceiling in 2004 is $87,900. Hence, Social Security payroll taxes as a share of earnings fall after the ceiling is passed – thus, the Social Security payroll tax may be thought of as regressive. The opponents to this view note that the above analysis only focuses on taxes paid, not benefits received. As shown in Table 9.3, Social Security redistributes from high earners to low earners, and the formula for the primary insurance amount offers extremely high replacement rates to very low earners, and much lower replacement rates to high earners. Thus, the net tax payment(taxes minus benefits) is likely to be progressive, not regressive. One critical assumption in this kind of analysis is how one computes lifetime benefits –e.g., do we assume that low earners and high earners live the same number of years?10. Let G stand for the individual’s gross earnings. The question assumes that the personfaces a marginal tax rate of 15% and a payroll tax of 7.45%. Thus, the person’s after-tax earnings (denoted by N) are N=(1-t earn-t payroll)G, or N=(1-0.15-0.0745)G, or N=0.7755G.It is assumed that the gross unemployment benefits, U, are equal to 50 percent of before-tax earnings, or U=0.5G. Net unemployment benefits, B, take out income taxes, so B=(1-t earn)U=(1-t earn)0.5G=(1-0.15)0.5G=0.425G. The percentage of the individual’s after-tax income that is replaced by UI is therefore equal to B/N, or 0.425G/0.7755G, which is approximately 54.8%.Unemployment benefits are about 55% of the individual’s previous after-tax income. The effects of unemployment insurance on unemployment area matter of considerable debate. While the high replacement rates from UI may increasethe duration of unemployment, the longer search time may reduce recurrence of unemployment by allowing time for a worker to find a better job match. Empiricalstudies seem to show that the hazard rate into employment spikes up around the time that benefits run out – perhaps suggesting that job matches are not really improving.Chapter 10 – Social Insurance II: Health Care1. The quotation contains several serious errors. First, concern with health care costs doesnot mean that health care is not a “good.” Economists do not care about the cost of health care per se. Rather, the issue is whether there are distortions in the market that lead to more than an efficient amount being consumed. Second, it makes a lot of difference how money is spent. One can create employment by hiring people to dig ditches and then fill them up, but this produces nothing useful in the way of goods and services. Thus, employment in the health care sector is not desirable in itself. It is desirable to the extent that it is associated with the production of an efficient quantity of health care services.2. a. Those who have a relatively high probability of needing the insurance are the oneswho are most likely to buy it. This raises the premium, which in turn, leads toselection by people who have an even higher probability of using it. The cyclecontinues until the price is so high that virtually no one purchases the policy.b.Employer-provided health insurance is deductible to the employer and not taxed tothe employee.c.Because of the tax subsidy, individuals may purchase more than the efficientamount of health insurance. That is, they “over-insure.” An interesting exampleof how the tax system leads to overinsurance is given in a recent Wall StreetJournal (January 19, 2004) article by Martin Feldstein. He gives an example oftwo different California Blue Cross health plans – identical in all respects exceptfor the deductible and annual premiums. The low-deductible plan (the “generous”plan) has a deductible of $500 per family member, up to a maximum of two andan annual premium of $8,460. Thus, the maximum out-of-pocket expense is$1,000. The high-deductible plan (the “less generous” plan) has a deductible of$2,500 per family member, up to a maximum of two, and an annual premium of$3,936. Thus, the maximum out-of-pocket expense is $5,000. Note that thepremium savings of $4,524 actually exceeds the maximum incremental deductiblepayment of $4,000 (which would only occur if the family had very high healthexpenses). In principle, the high deductible plan is unambiguously better. But thetraditional tax rules could lead an employer to choose the low deductible policy.If the employee faced a marginal tax rate of 45% (the sum of federal, state, andpayroll tax rates), then if the $4,524 premium saving was turned into taxablesalary, the individual’s net income would only rise by $2,488. Thus, families withhigh expected medical expenses do better with the “generous” plan, even though itis more costly in terms of premiums.3. a. D d=4.22–(0.044)(50)=2 visits per year.Total expenditure =(2)(50)=$100b.Now the individual pays only $5 per visit.D d = 4.22 – (0.044)(5) = 4 visits, with out-of-pocket costs of $20.Insurance company pays ($45)(4) = $180Total expenditure = $200, double its previous level.4. Examining Figure 10.1, we can see why health care costs increased for the state ofTennessee. As insurance coverage increases, this lowers the cost of medical expenses for those who were previously did not have insurance, which increases the overall amount of medical services they consume. Before receiving insurance, these people demand M o units of medical services, and the amount they pay is represented by the area OP o aM o.But after receiving insurance coverage, they demand M1amounts of medical services, paying only OjhM1, while their insurance pays jP o bh. The increase in insurance payments is sizable for two reasons – first, by providing coverage, it pays for the majority of the already sizable medical expenses incurred by this group, and second, the introduction of insurance makes the group consume even more medical services. In short, if the people who designed the Tennessee program had realized that the demand curve for medical services is downward sloping, they would not have been surprised at the consequences of their program.To explain why HMOs have been unable to contain long-run health care costs, it is necessary to consider the effect of technology on health care costs in the long-term. The inherent problem is that the market for medical care places a large premium on using the latest and most-developed medicines and machinery for treating patients. These technologies tend to be expensive. Hence, while introducing HMOs can lead to a once and for all decrease in the rate of change in health care costs, there is nothing that an HMO can do to lower the cost of continually providing the latest in medical treatments. 5. The goal of making the Medicare prescription drug benefit a one-time, permanentdecision is to reduce the adverse selection problem (no te: the current “Medigap”program operates in this manner to some extent – a senior citizen has choice over all 10 of the Medigap plans for only a short period of time after they turn 65, after which they may be denied based on their health). Imagine a cohort of people turning age 65 and becoming eligible for the Medicare drug benefit. If the decision to enter (or exit) could be made every year, then healthy senior citizens would have a strong incentive to wait until they became unhealthy and needed drugs, and then enter the prescription drug program (presumably resulting in economic losses for the program). Similarly, when people who were collecting the prescription drug benefit became healthy, they would have a strong incentive to “opt-out” of the prog ram. By making the decision opt-in at the beginning or not at all, the healthy younger seniors are likely initially cross-subsidizing the older seniors. Note that this “opt-in at the beginning” works because bad health and older age are positively correlated with each other. If, for example, younger seniors used more drugs (and perhaps older seniors used more inpatient care, etc.), then older seniors could simply stop paying annual premiums and give up their option of being in the program. If this scenario held empirically, this would exacerbate the adverse selection problem and the opt-in scenario would not completely solve the adverse selection problem.6. The budget constraint initially has units of Medigap on the x-axis, and other goods on they-axis. Given initial prices of $1 per unit for each good, and $30,000 of income, the budget constraint has a slope of -1, and the intercepts on both axes are at 30,000 units. It is assumed that the initial utility maximizing bundle consumes 5,000 units of Medigap, hence the indifference curve is tangent at (5000,25000). All of this is illustrated in the figure below.Medigapefficiency units30,000 5,000After the “minimum Medigap” mandate, the consumer can either choose 0 units of Medigap or 8,000 or more units of Medigap. Thus, part of the budget constraint is eliminated (though the overall shape remains the same as before). After the mandate, the point (0,30000) is available, as well as all of the points to the southeast of the point (8000,22000). Clearly, the person’s utility must fall since the preferred choice, (5000,25000) is no longer available. If the person attains a higher level of utility as (0,30000) compared with (8000,22000), the person chooses to not purchase Medigap. In this case, the marginal rate of substitution is no longer equal to the price ratio. This is illustrated below.Medigapefficiency units30,000 5,000 8,000。

Unit SevenSection AWhat the Hidden Persuaders Are up to Nowadays 参考译文当今隐藏的劝说者在干什么[1] 人们一直在问我，时至今日，隐藏的劝说者（广告人员）在干什么？因此，几个月来我反复拜访广告专家（劝说专家），我发现人口学家和动机研究者与我们的意见还十分一致，但今天广告人员还要倾听其他行为专家的意见。

也许这个世界已经比二十年前更有理性，但是更难以预言。

[2] 广告人员寻求可靠的预测，即我们这些顾客对他们的努力会作出什么样的反响。

几年前，他们知道，我们在讨论广告或产品时会由于礼貌而去说谎，因而广告界就越来越转向通过我们的身体来寻求我们真正感觉的线索。

[3] 拿我们的眼睛来说，有一种电脑化的机器，当眼睛看着印制的广告时，这机器就跟踪眼睛的运动，以判定广告中最有吸引力的那些词句。

某些广告人员曾试用瞳孔计（一种测量瞳孔受刺激后发生变化的仪器），以便得到对于一个广告或电视广告片的总体反映。

[4] 如果对某物产生兴趣，瞳孔放大，不过这也会导致错误的结论。

一个冷冻的油炸土豆商，收到令人高兴的报告，说在看他的电视广告时，瞳孔有显著扩大。

但是进一步的分析表明，那是由广告中发出咝咝声的牛排而不是由炸土豆所引起的。

再者，瞳孔计不能说明看电视的人喜欢或不喜欢一个广告（我们也会被令人讨厌的广告所激动）。

这使瞳孔计的一些使用者不满，但是其他一些人还坚持说它至少是有益的。

激发起兴趣是很重要的。

要是没有它，广告人员必然地要浪费金钱。

[5] 还有些仪器能提供声调分析。

首先录下正常的声音，然后再录下评论广告或产品时的声音。

计算机能分辨出我们所说的是应酬话，是出于礼貌的谎言，还是一个肯定的意见。

[6] 在对由孩子表演的两个广告电视片进行测试时，其他孩子对两片的评论似乎同样都是赞许的。

但是机器检测报告说，其中的一部广告片只是使孩子们感兴趣，而另一部则具有一种他们感到难以表述的感情效果。