曼昆经济学原理1章.docx
- 文档编号:26620989
- 上传时间:2023-06-20
- 格式:DOCX
- 页数:17
- 大小:29.23KB
曼昆经济学原理1章.docx
《曼昆经济学原理1章.docx》由会员分享,可在线阅读,更多相关《曼昆经济学原理1章.docx(17页珍藏版)》请在冰豆网上搜索。
曼昆经济学原理1章
1-TenPrinciplesofEconomics
ThewordeconomycomesfromtheGreekwordfor“onewhomanagesahousehold.”Atfirst,thisoriginmightseempeculiar.But,infact,householdsandeconomieshavemuchincommon.
Ahouseholdfacesmanydecisions.Itmustdecidewhichmembersofthehouseholddowhichtasksandwhateachmembergetsinreturn:
Whocooksdinner?
Whodoesthelaundry?
Whogetstheextradessertatdinner?
WhogetstochoosewhatTVshowtowatch?
Inshort,thehouseholdmustallocateitsscarceresourcesamongitsvariousmembers,takingintoaccounteachmember’sabilities,efforts,anddesires.
Likeahousehold,asocietyfacesmanydecisions.Asocietymustdecidewhatjobswillbedoneandwhowilldothem.Itneedssomepeopletogrowfood,otherpeopletomakeclothing,andstillotherstodesigncomputersoftware.Oncesocietyhasallocatedpeople(aswellasland,buildings,andmachines)tovariousjobs,itmustalsoallocatetheoutputofgoodsandservicesthattheyproduce.Itmustdecidewhowilleatcaviarandwhowilleatpotatoes.ItmustdecidewhowilldriveaPorscheandwhowilltakethebus.
Themanagementofsociety’sresourcesisimportantbecauseresourcesarescarce.Scarcitymeansthatsocietyhaslimitedresourcesandthereforecannotproduceallthegoodsandservicespeoplewishtohave.Justasahouseholdcannotgiveeverymembereverythingheorshewants,asocietycannotgiveeveryindividualthehigheststandardoflivingtowhichheorshemightaspire.
Economicsisthestudyofhowsocietymanagesitsscarceresources.Inmostsocieties,resourcesareallocatednotbyasinglecentralplannerbutthroughthecombinedactionsofmillionsofhouseholdsandfirms.Economiststhereforestudyhowpeoplemakedecisions:
howmuchtheywork,whattheybuy,howmuchtheysave,andhowtheyinvesttheirsavings.Economistsalsostudyhowpeopleinteractwithoneanother.Forinstance,theyexaminehowthemultitudeofbuyersandsellersofagoodtogetherdeterminethepriceatwhichthegoodissoldandthequantitythatissold.Finally,economistsanalyzeforcesandtrendsthataffecttheeconomyasawhole,includingthegrowthinaverageincome,thefractionofthepopulationthatcannotfindwork,andtherateatwhichpricesarerising.Althoughthestudyofeconomicshasmanyfacets,thefieldisunifiedbyseveralcentralideas.
Intherestofthischapter,welookatTenPrinciplesofEconomics.Theseprinciplesrecurthroughoutthisbookandareintroducedheretogiveyouanoverviewofwhateconomicsisallabout.Youcanthinkofthischapterasa“previewofcomingattractions.”
HOWPEOPLEMAKEDECISIONS
Thereisnomysterytowhatan“economy”is.WhetherwearetalkingabouttheeconomyofLosAngeles,oftheUnitedStates,orofthewholeworld,aneconomyisjustagroupofpeopleinteractingwithoneanotherastheygoabouttheirlives.
Becausethebehaviorofaneconomyreflectsthebehavioroftheindividualswhomakeuptheeconomy,westartourstudyofeconomicswithfourprinciplesofindividualdecisionmaking.
PRINCIPLE#1:
PEOPLEFACETRADEOFFS
Thefirstlessonaboutmakingdecisionsissummarizedintheadage:
“Thereisnosuchthingasafreelunch.”Togetonethingthatwelike,weusuallyhavetogiveupanotherthingthatwelike.Makingdecisionsrequirestradingoffonegoalagainstanother.
Considerastudentwhomustdecidehowtoallocatehermostvaluableresource—hertime.Shecanspendallofhertimestudyingeconomics;shecanspendallofhertimestudyingpsychology;orshecandividehertimebetweenthetwofields.Foreveryhourshestudiesonesubject,shegivesupanhourshecouldhaveusedstudyingtheother.Andforeveryhourshespendsstudying,shegivesupanhourthatshecouldhavespentnapping,bikeriding,watchingTV,orworkingatherpart-timejobforsomeextraspendingmoney.Orconsiderparentsdecidinghowtospendtheirfamilyincome.Theycanbuyfood,clothing,orafamilyvacation.Ortheycansavesomeofthefamilyincomeforretirementorthechildren’scollegeeducation.Whentheychoosetospendanextradollarononeofthesegoods,theyhaveonelessdollartospendonsomeothergood.
Whenpeoplearegroupedintosocieties,theyfacedifferentkindsoftradeoffs.Theclassictradeoffisbetween“gunsandbutter.”Themorewespendonnationaldefensetoprotectourshoresfromforeignaggressors(guns),thelesswecanspendonconsumergoodstoraiseourstandardoflivingathome(butter).Alsoimportantinmodernsocietyisthetradeoffbetweenacleanenvironmentandahighlevelofincome.Lawsthatrequirefirmstoreducepollutionraisethecostofproducinggoodsandservices.Becauseofthehighercosts,thesefirmsendupearningsmallerprofits,payinglowerwages,charginghigherprices,orsomecombinationofthesethree.Thus,whilepollutionregulationsgiveusthebenefitofacleanerenvironmentandtheimprovedhealththatcomeswithit,theyhavethecostofreducingtheincomesofthefirms’owners,workers,andcustomers.
Anothertradeoffsocietyfacesisbetweenefficiencyandequity.Efficiencymeansthatsocietyisgettingthemostitcanfromitsscarceresources.Equitymeansthatthebenefitsofthoseresourcesaredistributedfairlyamongsociety’smembers.Inotherwords,efficiencyreferstothesizeoftheeconomicpie,andequityreferstohowthepieisdivided.Often,whengovernmentpoliciesarebeingdesigned,thesetwogoalsconflict.
Consider,forinstance,policiesaimedatachievingamoreequaldistributionofeconomicwell-being.Someofthesepolicies,suchasthewelfaresystemorunemploymentinsurance,trytohelpthosemembersofsocietywhoaremostinneed.Others,suchastheindividualincometax,askthefinanciallysuccessfultocontributemorethanotherstosupportthegovernment.Althoughthesepolicieshavethebenefitofachievinggreaterequity,theyhaveacostintermsofreducedefficiency.Whenthegovernmentredistributesincomefromtherichtothepoor,itreducestherewardforworkinghard;asaresult,peopleworklessandproducefewergoodsandservices.Inotherwords,whenthegovernmenttriestocuttheeconomicpieintomoreequalslices,thepiegetssmaller.
Recognizingthatpeoplefacetradeoffsdoesnotbyitselftelluswhatdecisionstheywillorshouldmake.Astudentshouldnotabandonthestudyofpsychologyjustbecausedoingsowouldincreasethetimeavailableforthestudyofeconomics.Societyshouldnotstopprotectingtheenvironmentjustbecauseenvironmentalregulationsreduceourmaterialstandardofliving.Thepoorshouldnotbeignoredjustbecausehelpingthemdistortsworkincentives.Nonetheless,acknowledginglife’stradeoffsisimportantbecausepeoplearelikelytomakegooddecisionsonlyiftheyunderstandtheoptionsthattheyhaveavailable.
PRINCIPLE#2:
THECOSTOFSOMETHINGIS
WHATYOUGIVEUPTOGETIT
Becausepeoplefacetradeoffs,makingdecisionsrequirescomparingthecostsandbenefitsofalternativecoursesofaction.Inmanycases,however,thecostofsomeactionisnotasobviousasitmightfirstappear.
Consider,forexample,thedecisionwhethertogotocollege.Thebenefitisintellectualenrichmentandalifetimeofbetterjobopportunities.Butwhatisthecost?
Toanswerthisquestion,youmightbetemptedtoaddupthemoneyyouspendontuition,books,room,andboard.Yetthistotaldoesnottrulyrepresentwhatyougiveuptospendayearincollege.
Thefirstproblemwiththisansweristhatitincludessomethingsthatarenotreallycostsofgoingtocollege.Evenifyouquitschool,youwouldneedaplacetosleepandfoodtoeat.Roomandboardarecostsofgoingtocollegeonlytotheextentthattheyaremoreexpensiveatcollegethanelsewhere.Indeed,thecostofroomandboardatyourschoolmightbelessthantherentandfoodexpensesthatyouwouldpaylivingonyourown.Inthiscase,thesavingsonroomandboardareabenefitofgoingtocollege.
Thesecondproblemwiththiscalculationofcostsisthatitignoresthelargestcostofgoingtocollege—yourtime.Whenyouspendayearlisteningtolectures,readingtextbooks,andwritingpapers,youcannotspendthattimeworkingatajob.Formoststudents,thewagesgivenuptoattendschoolarethelargestsinglecostoftheireducation.
Theopportunitycostofanitemiswhatyougiveuptogetthatitem.Whenmakinganydecision,suchaswhethertoattendcollege,decisionmakersshouldbeawareoftheopportunitycoststhataccompanyeachpossibleaction.Infact,theyusuallyare.College-ageathleteswhocanearnmillionsiftheydropoutofschoolandplayprofessionalsportsarewellawarethattheiropportunitycostofcollegeisveryhigh.Itisnotsurprisingthattheyoftendecidethatthebenefitisnotworththecost.
PRINCIPLE#3:
RATIONALPEOPLETHINKATTHEMARGIN
Decisionsinlifearerarelyblackandwhitebutusuallyinvolveshadesofgray.Whenit’stimefordinner,thedecisionyoufaceisnotbetweenfastingoreatinglikeapig,butwhethertotakethatextraspoonfulofmashedpotatoes.Whenexamsrollaround,yourdecisionisnotbetweenblowingthemofforstudying24hoursaday,butwhethertospendanextrahourreviewingyournotesinsteadofwatchingTV.Economistsusethetermmarginalchangestodescribesmallincrementaladjustmentstoanexistingplanofaction.Keepinmindthat“margin”means“edge,”somarginalchangesareadjustmentsaroundtheedgesofwhatyouaredoing.
Inmanysituations,peoplemakethebestdecisionsbythinkingatthemargin.
Suppose,forinstance,thatyouaskedafriendforadviceabouthowmanyyearstostayinschool.IfheweretocompareforyouthelifestyleofapersonwithaPh.D
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 经济学原理