经济学原理i10秋季期中

期中考试2（A卷答案）注意：请将所有题目的答案写在答题册上，写在本试题纸上一律无效。一、判断题（判断并简要说明理由，必要时可以用图形。每题4分，共20分AstateoftheU.S.raisesitssalestaxfrom5percentto6percent.Thestaterevenuecommissionerforecastsa20percentincreaseinsalestaxrevenue.Thisforecastiscorrect.得销售入增加小于20％。Consideracountryimportsagoodfromabroad.Ifdemandisperfectlyinelastic,consumersdonotbenefitfromtradeandthereareonlylossesfromtrade.(Useadiagram)False.Consumerswillenjoyalowerprice(butnotmoretydemanded)andwillbenefitfromtrade.Benefitstoconsumersareevenlargerthanlossestoproducers,sotherearestillgainsfromtrade(shadedareainthediagrambelow).Coasianbargaining（谈判）cansolveproblemswithnegativeexternalities,butnotproblemswithpositiveexternalities.TheWashingtonD.C.Metro(subway)systemchargeshigherfaresduringrushhourthanduringtherestoftheday.Theonlyreasonforthisisthatdemandforsubwayridesduringrushhourishigherthandemandduringtherestoftheday.False.Higherdemandisonepossiblereason.Butthereisstillanother:Whenthesystemiscongested,eachadditionalriderimposescostsonotherriders.Increasingthefareduringrushhourinternalizesthisnegativeexternality.Ifgoodscanbegotforfree,thenneitheritsproducingnoritsusingcangenerate False.Agoodbeinggotforfreedoesnotmeanthatitsproducingandusingdoesnothavesocialcost.Infact,withoutapricetoreflectitssocialbenefitsandcosts,itsproducingandusingisoften二、选择题（每题3分，共36分。每题只有一个正确答案。在东门外一家面馆里，一碗牛肉面售价为16.8元，一份小菜售价为4元。如果点“牛肉面加小菜”套餐则只需要18.5元。对此，常去那里吃饭的学生发SupposethedemandforFrenchbreadrisesbecauseofitsbettertastes.ThentheconsumersurplusinthemarketforFrenchbreadwill ,producersurpluswill .Theproducersurplusinthemarketforflourwill ,consumersurplus(ormoreprecisely,netbenefitsofbuyers)will increase,increase,increase,increaseordecrease,increase,increase,increaseorincrease,increase,increase,increaseordecrease,increase,increase,EconomiststendtoseeticketscalawayforafewtoprofitwithoutproducinganythingofaninequitableinterferenceintheorderlyprocessofticketawayofincreasingtheefficiencyofticketanunproductiveactivitywhichshouldbemadeillegalBillGatesbecameoneoftherichestpeopleintheworldbysellingWindowsthroughouttheworld.Whatkindofbenefitsofinternationaltradecanthisfactbestillustrate?IncreasedvarietyofLowercoststhrougheconomiesofIncreasedEnhancedflowofIfCanadaweretosubsidizetheproductionofwoolblankets,andsellthemintheU.S.atartificiallylowprices,theU.S.economywouldbe ,theCanadaeconomywould ,andtheU.S.andCanadaeconomyasawholewouldbe worseoff,betteroff,worseofforbetterbetteroff,worseoff,worseofforbetterbetteroff,betteroff,betterbetteroff,worseoff,worseTheU.S.ernmenthasattimespressuredJapanto“voluntarily”limitthesaleofJapanesecarsintheUnitedStates.ComparedwithatariffwhichachievesthesamenumberofcarsimportedfromJapan，thisvoluntarylimitationpolicywillmaketheU.S.consumers theU.S.producers ;theU.S.ernment ;andtheU.S.asawhole worseoff;worseoff;worseoff;worsebetteroff;worseoff;unaffected;betterunaffected;unaffected;worseoff;worse以下理由中，不能斯谈判。则对于吸烟者而言，第种规定最有利，第种规定最不利。Fourroommatesareplanningtospendtheweekendintheirdormroomwatchingoldmovies,andtheyaredebatinghowmanytowatch.Hereistheirwillingnesstopayforeachfilm:First7542Second6431Third53104210Fifth3100Withinthedormroom,theshowingofamovieisapublicgood.Itcosts$8torentaConsiderthefollowingsituations.(a)AlltheroommatesdecidehowmanymoviestorentthroughCoasianbargaining.(b)Eachroommatedecidesindependentlyhowmanymoviestorent.(c)Alltheroommatesagreeinadvancetosplitequallythecostofrenting,andtheyuseamajorityruletodecidehowmanymoviestorent(i.e.,ifmorethanhalfofthemagreeanumberofmovies,thatnumberofmovieswillberent).Amongallthesituations,situationwillinducethehighestnumberofmovies,andsituation willinducethelowestnumberofmovies.(a),(a)and(c),(a),(b),Thedemandforfoodisrelativelyinelastic.Comparedwithothergoods,taxingfoodcanraisemoretaxrevenue,causelessdeadweightlossandimprovevertical-raisemoretaxrevenue,causelessdeadweightlossandworsenvertical-raisemoretaxrevenue,causemoredeadweightlossandworsenvertical-raiselesstaxrevenue,causemoredeadweightlossandimprovevertical-equity三、问答题（3小题，41分PublicPoliciestowardExternalities(10ThePristineRiverhastwopollutingfirmsonitsbanks.AcmeIndustrialandCreativeChemicalseachdump100tonsofglopintotherivereachyear.Thecostofreducingglopemissionspertonequals$10forAcmeand$100forCreative.Thelocalernmentwantstoreduceoverallpollutionfrom200tonsto50tons.Iftheernmentknowsthecostofreductionforeachfirm,whatreductionswillitimposetoreachitsoverallgoal?Whatwillbethecosttoeachfirmandthetotalcosttothefirmstogether？(2points)Iftheernmentknewthecostofreductionateachfirm,itwouldhaveAcmeeliminateallitspollution(atacostof$10pertontimes100tons=$1,000)andhaveCreativeeliminatehalfofitspollution(atacostof$100pertontimes50tons=$5,000).Thisminimizesthetotalcost($6,000)ofreducingthepollutionto50tons.Inamoretypicalsituation,theernmentdoesnotknowthecostofpollutionreductionforeachfirm.Iftheernmentdecidestoreachitsoverallgoalbyimposinguniformreductionsonthefirms,calculatethecosttoeachfirm,andthetotalcosttothefirmstogether.(2points)Ifeachfirmhadtoreducepollutionto25tons(soeachhadtoreducepollutionby75tons),thecosttoAcmewouldbe75x$10=$750andthecosttoCreativewouldbe75x$100=$7,500.Thetotalcostwouldbe$8,250.Nowsupposetheernmentgiveseachfirm25tonsoftradablepollutionpermits.Whosellspermitsandhowmanydoesitsell?Whatwouldbethepriceofpermits?Whatisthetotalcostofreductiontothefirmstogetherinthissituation?Doyoupreferpolicyinpart(b)orinthispart?(3points)Acmewillsellallofitspermitsatapricebetween$10and$100.Asaresult,AcmewillreduceitspollutiontozeroandCreativewillreduceitspollutionto50tons.Thusthetotalcostofreductiontothefirmsis100*$10+50*$100=$6,000.Wewouldpreferpolicyinthispart,becauseitreducesthesameamountofpollutionwithsmallertotalcost.Nowsupposetheernmentcouldnotdecidehowmuchpollutionissociallydesirable,butitknowsthateachtonofglopdumpedimposesasocialcostof$50.Whatshouldtheernmentdonow?Undersucha ernmentpolicy,howmuchpollutionwouldbereducedaltogether?Whatisthetotalcostofreductioninthissituation?Doyouthinkthecostminimizedforreducingthattotalamountofpollution?Explain.(3Theernmentshouldimposeacorrectivetaxof$50foreachtonofglopdumped.ThenAcmewillreduceitspollutiontozeroandCreativewillnotreducepollutionatall.Sothetotalamountofpollutionreductionis100tons.Thetotalcostofreductionis100*$10=$1,000.Thecostisindeedminimized,becauseauniformcorrectivetaximposedforeachfirmwillhavefirmswithlowerreductioncosttoreducepollutionandviceversa.Sothetotalcostisminimized.出口退税（13分画出一国出口某种产品的典型的市场供求图形（1分。Q现在考虑对出口企业所有产品都征税。在图形中表示这一政策的影响。由于该政策，国内企业的生产量如何变动，国内消费者的消费量如何变动？出口量如何变动？国内生产者福利如何变动？消费者福利如何变动？的福利如何图形并辅助文字说明。（4分）出口量下降，从线段CD缩短到CD’。生产者福利下降，从面积BDF减少到面积BD’F’。增加，从零增加到面积F’D’GF该国从国际贸易中获益减少，从面积CDE减少到面积CD’E’。AABCDGFEQ（不？的福利如何变动？（注：所结都与有何政策比较（4分）出口量增加，从线段CD延长到C’D。增加，从零增加到面积AA’C’G’。CDEFQ响你的回答？（4分）错误。出口企业的出口量比无税时增加了。出口量从线段CD增加到C’D（直观解释：此时国内消费者因负担减少了消费量，国内生产者面对世界价格不变，因而产量不变，则出口增加。）（1分）错误（或不一定。无谓损失从面积D’GD变为C’G’C。两个面积的大小