曼昆经济学原理微观经济学英文版习题答案考试章节筛选.docx
《曼昆经济学原理微观经济学英文版习题答案考试章节筛选.docx》由会员分享,可在线阅读,更多相关《曼昆经济学原理微观经济学英文版习题答案考试章节筛选.docx(139页珍藏版)》请在冰豆网上搜索。
曼昆经济学原理微观经济学英文版习题答案考试章节筛选
曼昆经济学原理微观经济学英文版
课后习题答案(考试章节筛选)
UNIT1
SOLUTIONSTOTEXTPROBLEMS:
QuickQuizzes
1.Thefourprinciplesofeconomicdecisionmakingare:
(1)peoplefacetradeoffs;
(2)thecostofsomethingiswhatyougiveuptogetit;(3)rationalpeoplethinkatthemargin;and(4)peoplerespondtoincentives.Peoplefacetradeoffsbecausetogetonethingthattheylike,theyusuallyhavetogiveupanotherthingthattheylike.Thecostofsomethingiswhatyougiveuptogetit,notjustintermsofmonetarycostsbutallopportunitycosts.Rationalpeoplethinkatthemarginbytakinganactionifandonlyifthemarginalbenefitsexceedthemarginalcosts.Peoplerespondtoincentivesbecauseastheycomparebenefitstocosts,achangeinincentivesmaycausetheirbehaviortochange.
2.Thethreeprinciplesconcerningeconomicinteractionsare:
(1)tradecanmakeeveryonebetteroff;
(2)marketsareusuallyagoodwaytoorganizeeconomicactivity;and(3)governmentscansometimesimprovemarketoutcomes.Tradecanmakeeveryonebetteroffbecauseitallowscountriestospecializeinwhattheydobestandtoenjoyawidervarietyofgoodsandservices.Marketsareusuallyagoodwaytoorganizeeconomicactivitybecausetheinvisiblehandleadsmarketstodesirableoutcomes.Governmentscansometimesimprovemarketoutcomesbecausesometimesmarketsfailtoallocateresourcesefficientlybecauseofanexternalityormarketpower.
3.Thethreeprinciplesthatdescribehowtheeconomyasawholeworksare:
(1)acountry’sstandardoflivingdependsonitsabilitytoproducegoodsandservices;
(2)pricesrisewhenthegovernmentprintstoomuchmoney;and(3)societyfacesashort-runtradeoffbetweeninflationandunemployment.Acountry’sstandardoflivingdependsonitsabilitytoproducegoodsandservices,whichinturndependsonitsproductivity,whichisafunctionoftheeducationofworkersandtheaccessworkershavetothenecessarytoolsandtechnology.Pricesrisewhenthegovernmentprintstoomuchmoneybecausemoremoneyincirculationreducesthevalueofmoney,causinginflation.Societyfacesashort-runtradeoffbetweeninflationandunemploymentthatisonlytemporaryandpolicymakershavesomeabilitytoexploitthisrelationshipusingvariouspolicyinstruments.
QuestionsforReview
1.Examplesoftradeoffsincludetimetradeoffs(suchasstudyingonesubjectoveranother,orstudyingatallcomparedtoengaginginsocialactivities)andspendingtradeoffs(suchaswhethertouseyourlasttendollarsonpizzaoronastudyguideforthattougheconomicscourse).
2.Theopportunitycostofseeingamovieincludesthemonetarycostofadmissionplusthetimecostofgoingtothetheaterandattendingtheshow.Thetimecostdependsonwhatelseyoumightdowiththattime;ifit'sstayinghomeandwatchingTV,thetimecostmaybesmall,butifit'sworkinganextrathreehoursatyourjob,thetimecostisthemoneyyoucouldhaveearned.
3.Themarginalbenefitofaglassofwaterdependsonyourcircumstances.Ifyou'vejustrunamarathon,oryou'vebeenwalkinginthedesertsunforthreehours,themarginalbenefitisveryhigh.Butifyou'vebeendrinkingalotofliquidsrecently,themarginalbenefitisquitelow.Thepointisthateventhenecessitiesoflife,likewater,don'talwayshavelargemarginalbenefits.
4.Policymakersneedtothinkaboutincentivessotheycanunderstandhowpeoplewillrespondtothepoliciestheyputinplace.Thetext'sexampleofseatbeltsshowsthatpolicyactionscanhavequiteunintendedconsequences.Ifincentivesmatteralot,theymayleadtoaverydifferenttypeofpolicy;forexample,someeconomistshavesuggestedputtingknivesinsteeringcolumnssothatpeoplewilldrivemuchmorecarefully!
Whilethissuggestionissilly,ithighlightstheimportanceofincentives.
5.Tradeamongcountriesisn'tagamewithsomelosersandsomewinnersbecausetradecanmakeeveryonebetteroff.Byallowingspecialization,tradebetweenpeopleandtradebetweencountriescanimproveeveryone'swelfare.
6.The"invisiblehand"ofthemarketplacerepresentstheideathateventhoughindividualsandfirmsareallactingintheirownself-interest,pricesandthemarketplaceguidethemtodowhatisgoodforsocietyasawhole.
7.Thetwomaincausesofmarketfailureareexternalitiesandmarketpower.Anexternalityistheimpactofoneperson’sactionsonthewell-beingofabystander,suchasfrompollutionorthecreationofknowledge.Marketpowerreferstotheabilityofasingleperson(orsmallgroupofpeople)toundulyinfluencemarketprices,suchasinatownwithonlyonewelloronlyonecabletelevisioncompany.Inaddition,amarketeconomyalsoleadstoanunequaldistributionofincome.
8.Productivityisimportantbecauseacountry'sstandardoflivingdependsonitsabilitytoproducegoodsandservices.Thegreateracountry'sproductivity(theamountofgoodsandservicesproducedfromeachhourofaworker'stime),thegreaterwillbeitsstandardofliving.
9.Inflationisanincreaseintheoveralllevelofpricesintheeconomy.Inflationiscausedbyincreasesinthequantityofanation'smoney.
10.Inflationandunemploymentarenegativelyrelatedintheshortrun.Reducinginflationentailscoststosocietyintheformofhigherunemploymentintheshortrun.
ProblemsandApplications
1.a.Afamilydecidingwhethertobuyanewcarfacesatradeoffbetweenthecostofthecarandotherthingstheymightwanttobuy.Forexample,buyingthecarmightmeantheymustgiveupgoingonvacationforthenexttwoyears.Sotherealcostofthecaristhefamily'sopportunitycostintermsofwhattheymustgiveup.
b.ForamemberofCongressdecidingwhethertoincreasespendingonnationalparks,thetradeoffisbetweenparksandotherspendingitemsortaxcuts.Ifmoremoneygoesintotheparksystem,thatmaymeanlessspendingonnationaldefenseoronthepoliceforce.Or,insteadofspendingmoremoneyontheparksystem,taxescouldbereduced.
c.Whenacompanypresidentdecideswhethertoopenanewfactory,thedecisionisbasedonwhetherthenewfactorywillincreasethefirm'sprofitscomparedtootheralternatives.Forexample,thecompanycouldupgradeexistingequipmentorexpandexistingfactories.Thebottomlineis:
Whichmethodofexpandingproductionwillincreaseprofitthemost?
d.Indecidinghowmuchtoprepareforclass,aprofessorfacesatradeoffbetweenthevalueofimprovingthequalityofthelecturecomparedtootherthingsshecoulddowithhertime,suchasworkingonadditionalresearch.
2.Whenthebenefitsofsomethingarepsychological,suchasgoingonavacation,itisn'teasytocomparebenefitstocoststodetermineifit'sworthdoing.Buttherearetwowaystothinkaboutthebenefits.Oneistocomparethevacationwithwhatyouwoulddoinitsplace.Ifyoudidn'tgoonvacation,wouldyoubuysomethinglikeanewsetofgolfclubs?
Thenyoucandecideifyou'dratherhavethenewclubsorthevacation.Asecondwayistothinkabouthowmuchworkyouhadtodotoearnthemoneytopayforthevacation;thenyoucandecideifthepsychologicalbenefitsofthevacationwereworththepsychologicalcostofworking.
3.Ifyouarethinkingofgoingskiinginsteadofworkingatyourpart-timejob,thecostofskiingincludesitsmonetaryandtimecosts,whichincludestheopportunitycostofthewagesyouaregivingupbynotworking.Ifthechoiceisbetweenskiingandgoingtothelibrarytostudy,thenthecostofskiingisitsmonetaryandtimecostsincludingthecosttoyouofgettingalowergradeinyourcourse.
4.Ifyouspend$100nowinsteadofsavingitforayearandearning5percentinterest,youaregivinguptheopportunitytospend$105ayearfromnow.Theideathatmoneyhasatimevalueisthebasisforthefieldoffinance,thesubfieldofeconomicsthathastodowithpricesoffinancialinstrumentslikestocksandbonds.
5.Thefactthatyou'vealreadysunk$5millionisn'trelevanttoyourdecisionanymore,sincethatmoneyisgone.Whatmattersnowisthechancetoearnprofitsatthemargin.Ifyouspendanother$1millionandcangeneratesalesof$3million,you'llearn$2millioninmarginalprofit,soyoushoulddoso.Youarerighttothinkthattheprojecthaslostatotalof$3million($6millionincostsandonly$3millioninrevenue)andyoushouldn'thavestartedit.That'strue,butifyoudon'tspendtheadditional$1million,youwon'thaveanysalesandyourlosseswillbe$5million.Sowhatmattersisnotthetotalprofit,buttheprofityoucanearnatthemargin.Infact,you'dpayupto$3milliontocompletedevelopment;anymorethanthat,andyouwon'tbeincreasingprofitatthemargin.
6.Harrysuggestslookingatwhetherproductivitywouldriseorfall.Productivityiscertainlyimportant,sincethemoreproductiveworkersare,thelowerthecostpergallonofpotion.Ronwantstolookataveragecost.ButbothHarryandRonaremissingtheothersideoftheequationrevenue.Afirmwantstomaximizeitsprofits,soitneedstoexaminebothcostsandrevenues.Thus,Hermioneisrightit’sbesttoexaminewhethertheextrarevenuewouldexceedtheextracosts.Hermioneistheonlyonewhoisthinkingatthemargin.
7.a.TheprovisionofSocialSecuritybenefitslowersanindividual’sincentivetosaveforretirement.Thebenefitsprovidesomelevelofincometotheindividualwhenheorsheretires.Thismeansthattheindividualisnotentirelydependentonsavingstosupportconsumptionthroughtheyearsinretirement.
b.Sinceapersongetsfewerafter-taxSocialSecuritybenefitsthegreaterishisorherearnings,thereisanincentivenottowork(ornotworkasmuch)