经济学基础第一章.ppt

1,TenPrinciplesofEconomics,Mankiw,CHAPTER1TENPRINCIPLESOFECONOMICS,Inthischapter,lookfortheanswerstothesequestions:,Whatkindsofquestionsdoeseconomicsaddress?Whataretheprinciplesofhowpeoplemakedecisions?Whataretheprinciplesofhowpeopleinteract?Whataretheprinciplesofhowtheeconomyasawholeworks?,CHAPTER1TENPRINCIPLESOFECONOMICS,WhatEconomicsIsAllAbout,Scarcity稀缺referstothelimitednatureofsocietysresources.Economicsisthestudyofhowsocietymanagesitsscarceresources,includinghowpeopledecidehowmuchtowork,save,andspend,andwhattobuyhowfirmsdecidehowmuchtoproduce,howmanyworkerstohirehowsocietydecideshowtodivideitsresourcesbetweennationaldefense,consumergoods,protectingtheenvironment,andotherneeds,0,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Decisionmakingisattheheartofeconomics.Thefirstfourprinciplesdealwithhowpeoplemakedecisions.,0,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Alldecisionsinvolvetrade-offs.Examples:Goingtoapartythenightbeforeyourmidtermleaveslesstimeforstudying.Havingmoremoneytobuystuffrequiresworkinglongerhours,whichleaveslesstimeforleisure.Protectingtheenvironmentrequiresresourcesthatmightotherwisebeusedtoproduceconsumergoods.,Principle#1:PeopleFaceTrade-offs交易,0,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Societyfacesanimportanttrade-off:efficiency效率vs.equity公平efficiency:gettingthemostoutofscarceresourcesequity:distributingprosperityfairlyamongsocietysmembersTrade-off:Toincreaseequity,canredistributeincomefromthewell-offtothepoor.Butthisreducestheincentivetoworkandproduce,andshrinksthesizeoftheeconomic“pie.”,Principle#1:PeopleFaceTrade-offs,0,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Makingdecisionsrequirescomparingthecostsandbenefitsofalternativechoices.Theopportunitycost机会成本ofanyitemiswhatevermustbegivenuptoobtainit.Itistherelevantcostfordecisionmaking.,Principle#2:TheCostofSomethingIsWhatYouGiveUptoGetIt,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Examples:Theopportunitycostofgoingtocollegeforayearisnotjustthetuition,books,andfees,butalsotheforegone先前wages.seeingamovieisnotjustthepriceoftheticket,butthevalueofthetimeyouspendinthetheater.,Principle#2:TheCostofSomethingIsWhatYouGiveUptoGetIt,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Apersonisrational理性ifshesystematicallyandpurposefully有目的doesthebestshecantoachieveherobjectives.Manydecisionsarenot“allornothing,”butinvolvemarginalchanges边际变化-smallincrementaladjustmentstoanexistingplan.Marginalcost，marginalbenefits，averageEvaluatingthecostsandbenefitsofmarginalchangesisanimportantpartofdecisionmaking.,Principle#3:RationalPeopleThinkattheMargin边际,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,Examples:Astudentconsiderswhethertogotocollegeforanadditionalyear,comparingthefees&foregonewagestotheextraincomehecouldearnwithanextrayearofeducation.Afirmconsiderswhethertoincreaseoutput,comparingthecostoftheneededlaborandmaterialstotheextrarevenue.,Principle#3:RationalPeopleThinkattheMargin,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEMAKEDECISIONS,incentive:somethingthatinducesapersontoact,i.e.theprospectofarewardorpunishment.Rationalpeoplerespondtoincentivesbecausetheymakedecisionsbycomparingcostsandbenefits.Examples:Inresponsetohighergasprices,salesof“hybrid”cars(e.g.,ToyotaPrius)rise.Inresponsetohighercigarettetaxes,teensmokingfalls.,Principle#4:PeopleRespondtoIncentives激励,ACTIVELEARNING1:Exercise,Youaresellingyour2002Mustang.Youhavealreadyspent$1000onrepairs.Atthelastminute,thetransmissiondies.Youcanpay$600tohaveitrepaired,orsellthecar“asis.”Ineachofthefollowingscenarios,shouldyouhavethetransmissionrepaired?A.Bluebookvalueis$6500iftransmissionworks,$5700ifitdoesntB.Bluebookvalueis$6000iftransmissionworks,$5500ifitdoesnt,11,ACTIVELEARNING1:Answers,Costoffixingtransmission=$600A.Bluebookvalueis$6500iftransmissionworks,$5700ifitdoesntBenefitoffixingthetransmission=$800($65005700).Itsworthwhiletohavethetransmissionfixed.B.Bluebookvalueis$6000iftransmissionworks,$5500ifitdoesntBenefitoffixingthetransmissionisonly$500.Paying$600tofixtransmissionisnotworthwhile.,12,ACTIVELEARNING1:Answers,Observations:The$1000youpreviouslyspentonrepairsisirrelevant无关.Whatmattersisthecostandbenefitofthemarginalrepair(thetransmission).ThechangeinincentivesfromscenarioAtoscenarioBcausedyourdecisiontochange.,13,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,An“economy”isjustagroupofpeopleinteractingwitheachother.Thenextthreeprinciplesdealwithhowpeopleinteract.,0,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,Ratherthanbeingself-sufficient,peoplecanspecializeinproducingonegoodorserviceandexchangeitforothergoods.Countriesalsobenefitfromtrade&specialization:getabetterpriceabroadforgoodstheyproducebuyothergoodsmorecheaplyfromabroadthancouldbeproducedathome,Principle#5:TradeCanMakeEveryoneBetterOff,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,Amarketisagroupofbuyersandsellers.(Theyneednotbeinasinglelocation.)“Organizeeconomicactivity”meansdeterminingwhatgoodstoproducehowtoproducethemhowmuchofeachtoproducewhogetsthem,Principle#6:MarketsAreUsuallyAGoodWaytoOrganizeEconomicActivity,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,Inamarketeconomy,thesedecisionsresultfromtheinteractionsofmanyhouseholdsandfirms.FamousinsightbyAdamSmithinTheWealthofNations(1776):Eachofthesehouseholdsandfirmsactsasif“ledbyaninvisiblehand”topromotegeneraleconomicwell-being.,Principle#6:MarketsAreUsuallyAGoodWaytoOrganizeEconomicActivity,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,Theinvisiblehandworksthroughthepricesystem:Theinteractionofbuyersandsellersdeterminespricesofgoodsandservices.Eachpricereflectsthegoodsvaluetobuyersandthecostofproducingthegood.Pricesguideself-interestedhouseholdsandfirmstomakedecisionsthat,inmanycases,maximizesocietyseconomicwell-being.,Principle#6:MarketsAreUsuallyAGoodWaytoOrganizeEconomicActivity,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,Importantroleforgovt:enforcepropertyrights财产权(withpolice,courts)Peoplearelessinclinedtowork,produce,invest,orpurchaseiflargeriskoftheirpropertybeingstolen.Arestaurantwontservemealsifcustomersdonotpaybeforetheyleave.AmusiccompanywontproduceCDsiftoomanypeopleavoidpayingbymakingillegalcopies.,Principle#7:GovernmentsCanSometimesImproveMarketOutcomes,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,Govtmayaltermarketoutcometopromoteefficiencymarketfailure市场失灵,whenthemarketfailstoallocatesocietysresourcesefficiently.Causes:Externalities外部性,whentheproductionorconsumptionofagoodaffectsbystanders(e.g.pollution)marketpower市场力量,asinglebuyerorsellerhassubstantialinfluenceonmarketprice(e.g.monopoly)Insuchcases,publicpolicymayincreaseefficiency.,Principle#7:GovernmentsCanSometimesImproveMarketOutcomes,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWPEOPLEINTERACT,GovtmayaltermarketoutcometopromoteequityIfthemarketsdistributionofeconomicwell-beingisnotdesirable值,taxorwelfarepoliciescanchangehowtheeconomic“pie”isdivided.,Principle#7:GovernmentsCanSometimesImproveMarketOutcomes,ACTIVELEARNING2:DiscussionQuestions,Ineachofthefollowingsituations,whatisthegovernmentsrole?Doesthegovernmentsinterventionimprovetheoutcome?a.PublicschoolsforK-12b.Workplacesafetyregulationsc.Publichighwaysd.Patentlaws,whichallowdrugcompaniestochargehighpricesforlife-savingdrugs,22,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWTHEECONOMYASAWHOLEWORKS,Thelastthreeprinciplesdealwiththeeconomyasawhole.,0,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWTHEECONOMYASAWHOLEWORKS,Hugevariationinlivingstandardsacrosscountriesandovertime:Averageincomeinrichcountriesismorethantentimesaverageincomeinpoorcountries.TheU.S.standardoflivingtodayisabouteighttimeslargerthan100yearsago.,Principle#8:Acountrysstandardoflivingdependsonitsabilitytoproducegoods&services.,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWTHEECONOMYASAWHOLEWORKS,Themostimportantdeterminantoflivingstandards:productivity,theamountofgoodsandservicesproducedperunitoflabor.Productivitydependsontheequipment,skills,andtechnologyavailabletoworkers.Otherfactors(e.g.,laborunions,competitionfromabroad)havefarlessimpactonlivingstandards.,Principle#8:Acountrysstandardoflivingdependsonitsabilitytoproducegoods&services.,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWTHEECONOMYASAWHOLEWORKS,Inflation通胀:increasesinthegenerallevelofprices.Inthelongrun,inflationisalmostalwayscausedbyexcessivegrowthinthequantityofmoney,whichcausesthevalueofmoneytofall.Thefasterthegovtcreatesmoney,thegreatertheinflationrate.,Principle#9:Pricesrisewhenthegovernmentprintstoomuchmoney.,CHAPTER1TENPRINCIPLESOFECONOMICS,HOWTHEECONOMYASAWHOLEWORKS,Intheshort-run(12years),manyeconomicpoliciespushinflationandunemploymentinoppositedirections.Otherfactorscanmakethistradeoffmoreorlessfavorable,butthetradeoffisalwayspresent.,Principle#10:Societyfacesashort-runtradeoffbetweeninflationandunemployment,CHAPTER1TENPRINCIPLESOFECONOMICS,CONCLUS