《曼昆宏观经济学》第二十四章MeasuringtheCostofLiving

iilM9h!呼眈ir*?'；i2•▼•• ••iWB；MeasuringtheCostofLivingMeasuringtheCostofLivingLastchapter,welookedathoweconomistsuseGDPtomeasurethequantityofgoodsandservicesthattheeconomyisproducing.Thischapter,weexaminesthathoweconomistsmeasuretheoverallcostofliving.Consumerpriceindex一awayofturningdollarfiguresintomeaningfulmeasuresofpurchasingpower.MeasuringtheCostofLivingInflationreferstoasituationinwhichtheeconomy'soverallpricelevelisrising.Theinflationrateisthepercentagechangeinthepricelevelfromthepreviousperiod・ContentTheconsumerpriceindexhowtheconsumerpriceindexiscalculatedProblemsinmeasuringthecostoflivingTheGDPdeflatorversustheCPICorrecteconomicvariablesfortheeffectsofinflationDollarfiguresfromdifferenttimesIndexationRealandnominalinterestratesTHECONSUMERPRICEINDEXTheconsumerpriceindex(CPI)isameasureoftheoverallcostofthegoodsandservicesboughtbyatypicalconsumer.TheBureauofLaborStatisticsreportstheCPIeachmonth.Itisusedtomonitorchangesinthecostoflivingovertime.

资料来源，国家统计爲 新华社记者周大庆编制。HowtheConsumerPriceIndexIsHowtheConsumerPriceIndexIsCalculatedHowtheConsumerPriceIndexIsHowtheConsumerPriceIndexIsCalculated•FixtheBasket:Determinewhatpricesaremostimportanttothetypicalconsumer.-TheBureauofLaborStatistics(BLS)identifiesamarketbasketofgoodsandservicesthetypicalconsumerbuys.一TheBLSconductsmonthlyconsumersurveystosettheweightsforthepricesofthosegoodsandservices・•FindthePrices:Findthepricesofeachofthegoodsandservicesinthebasketforeachpointintime.•ComputetheBasket'sCost:Usethedataonpricestocalculatethecostofthebasketofgoodsandservicesatdifferenttimes.•ChooseaBaseYearandComputetheIndex:一Designateoneyearasthebaseyear,makingitthebenchmarkagainstwhichotheryearsarecompared・一Computetheindexbydividingthepriceofthebasketinoneyearbythepriceinthebaseyearandmultiplyingby100.Comsumerpriceindex(CPI)xlOO_PriceofbasketofgoodsandservicesxlOOPriceofbasketinbaseyear•Computetheinflationrate:Theinflationrateisthepercentagechangeinthepriceindexfromtheprecedingperiod.•TheInflationRate一Theinflationrateiscalculatedasfollows:xlOOCPIinYear1T.厂.“小CPIinYear2-CPIinYear1InflationRateinYearxlOOCPIinYear1Copyright©2004South-WesternCopyright©2004South-WesternCopyright©2004South-WesternCopyright©2004South-WesternTable1CalculatingtheConsumerPriceIndexand"theInflationRate:AnExample 丄Step1:SurveyConsumerstoDetermineaFixedBasketofGoods4hotdogs,2hamburgersStep2:FindthePriceofEachGoodinEachYearYearPriceofHotDogs PriceofHamburgers200120022003$1 $234Step3:ComputetheCostoftheBasketofGoodsinEachYearStep3:ComputetheCostoftheBasketofGoodsinEachYearCopyright©2004South-WesternCopyright©2004South-WesternStep3:ComputetheCostoftheBasketofGoodsinEachYearStep3:ComputetheCostoftheBasketofGoodsinEachYearCopyright©2004South-WesternCopyright©2004South-Western200120022003($1perhotdog x 4hotdogs) +($2perhamburger x2hamburgers) =$8($2perhotdog x 4hotdogs)十($3perhamburger x2hamburgers) =$14($3perhotdog x 4hotdogs) +($4perhamburger x2hamburgers) =$20Copyright©2004South-WesternCopyright©2004South-WesternCopyright©2004South-WesternCopyright©2004South-WesternStep4:ChooseOneYearasaBaseYear(2001)andComputetheConsumerPriceIndexinEachYear200120022003($8/$8)X100=100($14/$8)X100=175($20/$8)X100=250Yable1CalculatingtheConsumerPriceIndexand「theInflationRate:AnExample £Step5:UsetheConsumerPriceIndextoComputetheInflationRatefromPreviousYear20022003(175—100)/100X100=20022003(250一175)/175X100=43%HowtheConsumerPriceIndexIsCalculated•CalculatingtheConsumerPriceIndexandtheInflationRate:AnotherExample-BaseYearis2002.-Basketofgoodsin2002costs$1,200.-Thesamebasketin2004costs$1,236.-CPI=($1,236/$1,200)x100=103.-Pricesincreased3percentbetween2002and2004.Foodandbeverages17% 、TransportationEducationandcommunication6%6%6%41%

HousingMedicalcareRecreationOthergoodsApparelandservicesChina食品:31.79%食品:31.79%烟酒及用品：3.49%居住:17.22%交通运输：9.95%医疗保健个人用品：9.64%衣着:.52%家庭设备及维修服务：5.64%娱乐教育文化用品及服务：13.75%Discussion•Whichdoyouthinkhasagreatereffectontheconsumerpriceindex:a10percentincreaseinthepriceofchickenora10percentincreaseinthepieceofcaviar?Why?ProblemsinMeasuringtheCostofLivingTheCPIisanaccuratemeasureoftheselectedgoodsthatmakeupthetypicalbundle,butitisnotaperfectmeasureofthecostofliving.WHY?ProblemsinMeasuringtheCostofLivingSubstitutionbiasIntroductionofnewgoodsUnmeasuredqualitychanges•SubstitutionBias一Thebasketdoesnotchangetoreflectconsumerreactiontochangesinrelativeprices・Consumerssubstitutetowardgoodsthathavebecomerelativelylessexpensive.Theindexoverstatestheincreaseincostoflivingbynotconsideringconsumersubstitution.•IntroductionofNewGoods一Thebasketdoesnotreflectthechangeinpurchasingpowerbroughtonbytheintroductionofnewproducts.•Newproductsresultingreatervariety,whichinturnmakeseachdollarmorevaluable・•Consumersneedfewerdollarstomaintainanygivenstandardofliving.•UnmeasuredQualityChanges一Ifthequalityofagoodrisesfromoneyeartothenext,thevalueofadollarrises,evenifthepriceofthegoodstaysthesame.一Ifthequalityofagoodfallsfromoneyeartothenext,thevalueofadollarfalls,evenifthepriceofthegoodstaysthesame・一TheBLStriestoadjustthepriceforconstantquality,butsuchdifferencesarehardtomeasure.•Thesubstitutionbias,introductionofnewgoods,andunmeasuredqualitychangescausetheCPItooverstatethetruecostofliving.-TheissueisimportantbecausemanygovernmentprogramsusetheCPItoadjustforchangesintheoveralllevelofprices・-TheCPIoverstatesinflationbyabout1percentagepointperyear.TheGDPDeflatorversustheTheGDPDeflatorversustheConsumerPriceIndexTheGDPDeflatorversustheTheGDPDeflatorversustheConsumerPriceIndex•TheGDPdeflatoriscalculatedasfollows:GDPdeflator=NominalGDPxlOOGDPdeflator=NominalGDPxlOORealGDP•TheBLScalculatesotherpricesindexes:一Theindexfordifferentregionswithinthecountry.一Theproducerpriceindex,whichmeasures

thecostofabasketofgoodsandservices

boughtbyfirmsratherthanconsumers・Discussion•IfthepriceofaNavysubmarinerises,istheconsumepriceindexortheGDPdeflatoraffectedmore?Why?TheGDPDeflatorversustheTheGDPDeflatorversustheConsumerPriceIndexTheGDPDeflatorversustheTheGDPDeflatorversustheConsumerPriceIndexEconomistsandpolicymakersmonitorboththeGDPdeflatorandtheconsumerpriceindextogaugehowquicklypricesarerising.Therearetwoimportantdifferencesbetweentheindexesthatcancausethemtodiverge.TheGDPdeflatorreflectsthepricesofallgoodsandservicesproduceddomestically,whereas......theconsumerpriceindexreflectsthepricesofallgoodsandservicesboughtbyconsumers.Theconsumerprice/nc/excomparesthepriceofafixedbasketofgoodsandservicestothepriceofthebasketinthebaseyear(onlyoccasionallydoestheBLSchangethebasket)......whereastheGDPdeflatorcomparesthepriceofcurrentlyproducedgoodsandservicestothepriceofthesamegoodsandservicesinthebaseyear.Figure2TwoMeasuresofInflationCORRECTINGECONOMICCORRECTINGECONOMICVARIABLESFORTHEEFFECTSOFINFLATIONCORRECTINGECONOMICCORRECTINGECONOMICVARIABLESFORTHEEFFECTSOFINFLATION•Priceindexesareusedtocorrectfortheeffectsofinflationwhencomparingdollarfiguresfromdifferenttimes.Copyright©2004South-WesternCopyright©2004South-WesternDollarFiguresfromDifferentTimes•Dothefollowingtoconvert(inflate)Babe

Ruth'swagesin1931todollarsin2001:c[ c[ Pricelevelin2001Salary200]=Salary1Q31x 72001 71931Pricelevelin1931177=$80,000x-^15.2=$931,579

TabIe^2ThelVIosFPopuTarMovles^fAllTimes，InflationAdjustedFilmYearofReleaseTotalDomesticGross(inmillionsof2001dollars)1.GonewiththeWind1939$1,0022.StarWars19778663.TheSoundofMusic19656954.E.T.:TheExtra-Terrestrial19826875.Titanic19976406.TheTenCommandments19566397.Jaws19756258.DoctorZhivago19655919.TheJungleBook196751910.SnowWhiteandtheSevenDwarfs1937518

Indexation•Whensomedollaramountisautomaticallycorrectedforinflationbylaworcontract,theamountissaidtobeindexedforinflation.RealandNominalInterestRates•Interestrepresentsapaymentinthefutureforatransferofmoneyinthepast.RealandNominalInterestRatesThenominalinterestrateistheinterestrateusuallyreportedandnotcorrectedforinflation.-Itistheinterestratethatabankpays.Therealinterestrateisthenominalinterestratethatiscorrectedfortheeffectsofinflation.RealandNominalInterestRatesYouborrowed$1,000foroneyear.Nominalinterestratewas15%.Duringtheyearinflationwas10%.Realinterestrate=Nominalinterestrate—Inflation=15%・10%=5%

Figure3RealandNominalInterestRates

Discussion•Overalongtime,thepriceofacandybarrosefrom$0.10to$0.60.overthesameperiod,theconsumerpriceindexrosefrom150to300.Adjustedforoverallinflation,howmuchdidthepriceofthecandybarchange?>Supposethataborrowerandalenderagreeonthenominalinterestratetobepaidonaloan.Theninflationturnsouttobehigherthantheybothexpected.a.Istherealinterestrateonthisloanhigherorlowerthanexpected?Doesthelendergainorlosefromthisunexpectedlyhighinflation?Doestheborrowergainorlose?•Inflationduringthe1970swasmuchhigherthanmostpeoplehadexpectedwhenthedecadebegan.Howdidthisaffecthomeownerswhoobtainedfixed-ratemortgagesduringthe1960s?Howdiditaffectthebanksthatlentthemoney?SummarySum