曼昆經(jīng)濟學原理微觀經(jīng)濟學英文版習題答案

1、Chapter1TenPrinciplesofEconomics?11UNIT1SOLUTIONSTOTEXTPROBLEMS:QuickQuizzes1.Thefourprinciplesofeconomicdecisionmakingare:(1)peoplefacetradeoffs(2)thecostofsomethingiswhatyougiveuptogetit(3)rationalpeoplethinkatthemargi

2、n(4)peoplerespondtoincentives.Peoplefacetradeoffsbecausetogetonethingthattheyliketheyusuallyhavetogiveupanotherthingthattheylike.Thecostofsomethingiswhatyougiveuptogetitnotjustintermsofmoarycostsbutallopptunitycosts.Rati

3、onalpeoplethinkatthemarginbytakinganactionifonlyifthemarginalbenefitsexceedthemarginalcosts.Peoplerespondtoincentivesbecauseastheycomparebenefitstocostsachangeinincentivesmaycausetheirbehavitochange.2.Thethreeprinciplesc

4、oncerningeconomicinteractionsare:(1)tradecanmakeeveryonebetteroff(2)marketsareusuallyagoodwaytoganizeeconomicactivity(3)governmentscansometimesimprovemarketoutcomes.Tradecanmakeeveryonebetteroffbecauseitallowscountriesto

5、specializeinwhattheydobesttoenjoyawidervarietyofgoodsservices.Marketsareusuallyagoodwaytoganizeeconomicactivitybecausetheinvisiblehleadsmarketstodesirableoutcomes.Governmentscansometimesimprovemarketoutcomesbecausesometi

6、mesmarketsfailtoallocateresourcesefficientlybecauseofanexternalitymarketpower.3.Thethreeprinciplesthatdescribehowtheeconomyasawholewksare:(1)acountry’sstardoflivingdependsonitsabilitytoproducegoodsservices(2)pricesrisewh

7、enthegovernmentprintstoomuchmoney(3)societyfacesashtruntradeoffbetweeninflationunemployment.Acountry’sstardoflivingdependsonitsabilitytoproducegoodsserviceswhichinturndependsonitsproductivitywhichisafunctionoftheeducatio

8、nofwkerstheaccesswkershavetothenecessarytoolstechnology.Pricesrisewhenthegovernmentprintstoomuchmoneybecausememoneyincirculationreducesthevalueofmoneycausinginflation.Societyfacesashtruntradeoffbetweeninflationunemployme

9、ntthatisonlytemparypolicymakershavesomeabilitytoexploitthisrelationshipusingvariouspolicyinstruments.QuestionsfReview1.Examplesoftradeoffsincludetimetradeoffs(suchasstudyingonesubjectoveranotherstudyingatallcomparedtoeng

10、aginginsocialactivities)spendingtradeoffs(suchaswhethertouseyourlasttendollarsonpizzaonastudyguidefthattougheconomicscourse).2.Theopptunitycostofseeingamovieincludesthemoarycostofadmissionplusthetimecostofgoingtothetheat

11、erattendingtheshow.ThetimecostdependsonwhatelseyoumightdowiththattimeifitsstayinghomewatchingTVthetimecostmaybesmallbutifitswkinganextrathreehoursatyourjobthetimecostisthemoneyyoucouldhaveearned.3.Themarginalbenefitofagl

12、assofwaterdependsonyourcircumstances.Ifyouvejustrunamarathonyouvebeenwalkinginthedesertsunfthreehoursthemarginalbenefitisveryhigh.Butifyouvebeendrinkingalotofliquidsrecentlythemarginalbenefitisquitelow.Thepointisthateven

13、thenecessitiesoflifelikewaterdontalwayshavelargemarginalbenefits.4.Policymakersneedtothinkaboutincentivessotheycanundersthowpeoplewillrespondtothepoliciestheyputinplace.Thetextsexampleofseatbeltsshowsthatpolicyactionscan

14、havequiteunintendedconsequences.Ifincentivesmatteralottheymayleadtoaverydifferenttypeofpolicyfexamplesomeeconomistshavesuggestedputtingknivesinsteeringcolumnssothatpeoplewilldrivemuchmecarefully!Whilethissuggestionissill

15、yithighlightstheimptanceofincentives.Chapter1TenPrinciplesofEconomics?33ofwking.3.Ifyouarethinkingofgoingskiinginsteadofwkingatyourparttimejobthecostofskiingincludesitsmoarytimecostswhichincludestheopptunitycostofthewage

16、syouaregivingupbynotwking.Ifthechoiceisbetweenskiinggoingtothelibrarytostudythenthecostofskiingisitsmoarytimecostsincludingthecosttoyouofgettingalowergradeinyourcourse.4.Ifyouspend$100nowinsteadofsavingitfayearearning5pe

17、rcentinterestyouaregivinguptheopptunitytospend$105ayearfromnow.Theideathatmoneyhasatimevalueisthebasisfthefieldoffinancethesubfieldofeconomicsthathastodowithpricesoffinancialinstrumentslikestocksbonds.5.Thefactthatyouvea

18、lreadysunk$5millionisntrelevanttoyourdecisionanymesincethatmoneyisgone.Whatmattersnowisthechancetoearnprofitsatthemargin.Ifyouspendanother$1millioncangeneratesalesof$3millionyoullearn$2millioninmarginalprofitsoyoushouldd

19、oso.Youarerighttothinkthattheprojecthaslostatotalof$3million($6millionincostsonly$3millioninrevenue)youshouldnthavestartedit.Thatstruebutifyoudontspendtheadditional$1millionyouwonthaveanysalesyourlosseswillbe$5million.So

20、whatmattersisnotthetotalprofitbuttheprofityoucanearnatthemargin.Infactyoudpayupto$3milliontocompletedevelopmentanymethanthatyouwontbeincreasingprofitatthemargin.6.Harrysuggestslookingatwhetherproductivitywouldrisefall.Pr

21、oductivityiscertainlyimptantsincethemeproductivewkersarethelowerthecostpergallonofpotion.Ronwantstolookataveragecost.ButbothHarryRonaremissingtheothersideoftheequation?revenue.Afirmwantstomaximizeitsprofitssoitneedstoexa

22、minebothcostsrevenues.ThusHermioneisright?it’sbesttoexaminewhethertheextrarevenuewouldexceedtheextracosts.Hermioneistheonlyonewhoisthinkingatthemargin.7.a.TheprovisionofSocialSecuritybenefitslowersanindividual’sincentive

23、tosavefretirement.Thebenefitsprovidesomelevelofincometotheindividualwhenhesheretires.Thismeansthattheindividualisnotentirelydependentonsavingstosupptconsumptionthroughtheyearsinretirement.b.SinceapersongetsfeweraftertaxS

24、ocialSecuritybenefitsthegreaterishisherearningsthereisanincentivenottowk(notwkasmuch)afterage65.ThemeyouwktheloweryouraftertaxSocialSecuritybenefitswillbe.ThusthetaxationofSocialSecuritybenefitsdiscourageswkefftafterage6

25、5.8.a.Whenwelfarerecipientswhoareabletowkhavetheirbenefitscutoffaftertwoyearstheyhavegreaterincentivetofindjobsthaniftheirbenefitsweretolastfever.b.Thelossofbenefitsmeansthatsomeonewhocantfindajobwillgetnoincomeatallsoth

26、edistributionofincomewillbecomelessequal.Buttheeconomywillbemeefficientsincewelfarerecipientshaveagreaterincentivetofindjobs.Thusthechangeinthelawisonethatincreasesefficiencybutreducesequity.9.Byspecializingineachtaskyou

27、yourroommatecanfinishthechesmequickly.Ifyoudividedeachtaskequallyitwouldtakeyoumetimetocookthanitwouldtakeyourroommateitwouldtakehimmetimetocleanthanitwouldtakeyou.Byspecializingyoureducethetotaltimespentonches.Similarly

28、countriescanspecializetrademakingbothbetteroff.FexamplesupposeittakesSpanishwkerslesstimetomakeclothesthanFrenchwkersFrenchwkerscanmakewinemeefficientlythanSpanishwkers.ThenSpainFrancecanbothbenefitifSpanishwkersproducea