消费者物价指数

Copyright©2004South-Western©2007ThomsonSouth-WesternCopyright©2004South-WesternMeasuringtheCostofLiving•ConsumerPriceIndex(CPI）：消費者物價指數•showsthecostofabasketofgoodsandservicesboughtbyatypicalfamilyrelativetothecostofthesamebasketinthebaseyear.‧usedtomonitorchangesinthecostoflivingovertime.WhentheCPIrises,thetypicalfamilyhastospendmoredollarstomaintainthesamestandardofliving.Copyright©2004South-WesternFYI:WhatIsintheCPI’sBasket?17%Transportation15%FoodandbeveragesMedicalcare6%Recreation6%Apparel4%Othergoodsandservices4%42%Housing6%EducationandcommunicationCopyright©2004South-WesternHowtocalculateCPI•TheCPIiscalculatedasfollows:000CPI=100tPQPQanothermeasureofpricechangeCopyright©2004South-WesternInflationRate•TheInflationRate（π）：通貨膨脹率＝物價上漲率•Whenπ0：deflation(通貨緊縮)11CPIinYear2-CPIinYear1InflationRateinYear2=100CPIinYear1ttttPPPPP亦即Copyright©2004South-WesternTable24.1CalculatingCPI&InflationRate:AnExampleCopyright©2004South-WesternTable24.1CalculatingCPI&InflationRate:AnExampleCopyright©2004South-WesternProblemsinMeasuringtheCostofLiving•CPI：notaperfectmeasureofcostofliving：(1)Substitutionbias(2)Introductionofnewgoods(3)Unmeasuredqualitychanges•causetheCPItooverstatethetruecostofliving.Copyright©2004South-WesternCh23:TheGDPDeflator•TheGDPdeflatoriscalculatedasfollows:0NominalGDPGDPdeflator=100RealGDP=100tttPQPQalsoameasureofpricechangeCopyright©2004South-WesternTheGDPDeflatorvs.CPI•EconomistsandpolicymakersmonitorboththeGDPdeflatorandCPItogaugehowquicklypricesarerising.•twoimportantdifferencestodiverge:•produceddomesticallyvs.boughtbyconsumers•currentlyproducedvs.afixedbasketCopyright©2004South-WesternTaiwan:2measuresofinflationFIGURE24.2InflationRateCalculatedfromtheImplicitGDPPriceDeflatorandCalculatedfromtheCPI-1001020304050196019641968197219761980198419881992199620002004YearAnnualInflationRate(%)GDPdeflatorCPICopyright©2004South-WesternTaiwandata：πInflationrate%(GDPdeflator)Inflationrate%(CPI)1961-20073.974.351961-19703.642.921971-198010.3311.071981-19903.093.151991-20001.912.592001-2007-0.490.831974π=47.50%1980π=19.01%1981π=16.32%2001-2003π0Copyright©2004South-WesternOtherPriceIndex•Theindexfordifferentregions/sectorswithinthecountry.•TheProducerPriceIndex（生產者物價指數）,whichmeasuresthecostofabasketofgoodsandservicesboughtbyfirmsratherthanconsumers.Copyright©2004South-WesternCorrectingEconomicVariablesfortheEffectsofInflation•Priceindexesareusedtocorrectfortheeffectsofinflation•whencomparingdollarfiguresfromdifferenttimes.Copyright©2004South-WesternDollarFiguresfromDifferentTimes•Toconvert(inflate)Ruth’swagesin1931todollarsin2001:20011931Pricelevelin2001SalarySalaryPricelevelin1931250$1,00010$25,000100,,,otottotorWWunitsPPWPPo已知W,求算Copyright©2004South-WesternIndexation（指數化）•Whensomedollaramountisautomaticallycorrectedforinflationbylaworcontract,theamountissaidtobeindexedforinflation.•Indexationforwage•Indexationforinterestrate•機動調整Copyright©2004South-WesternRealandNominalInterestRates•Interestrepresentsapaymentinthefutureforatransferofmoneyinthepast.•Nominalinterestrate（R，名目利率）:theinterestrateusuallyreported.•Itistheinterestratethatabankpays.•Realinterestrate（r，實質利率）:nominalinterestratecorrectedfortheeffectsofinflation.Copyright©2004South-WesternRealandNominalInterestRates•Youlendout$100foroneyear.P=$1/candy•Nominalinterestratewas10%.•Duringtheyearinflationwas6%.•Present$100/$1=100unitsofcandies•$100*(1+10%)/[$1*(1+6%)]=103.7unitsofcandies•Realreturn=3.7units,realrateofreturn=3.7%•Realinterestrate（realrateofreturn）近似=Nominalinterestrate–Inflationrate=10%-6%=4%(r=R-π)Copyright©2004South-WesternTaiwan:RandπFIGURE24.3TheNominalInterestRateandtheInflationRate-10.000.0010.0020.0030.0040.0050.00196219671972197719821987199219972002YearInterestRateandInflationRateinPercentNominalInterestRateInflationRateCopyright©2004South-WesternTaiwandata：πandRInflationrate%(CPI)NominalR%1961-20064.415.101961-19702.924.581971-198011.076.951981-19903.155.951991-20002.595.062001-20060.671.44197447.508.50198019.019.75198116.3210.252001-2006(-)零利率年代Copyright©2004South-WesternTaiwandata:rFIGURE24.3bRealInterestRate-45.00-40.00-35.00-30.00-25.00-20.00-15.00-10.00-5.000.005.0010.00196219671972197719821987199219972002YearRealInterestRateinPercentCopyright©2004South-WesternR,r,andexpectation•r=R-πSor0ifRπrRifπ0•契約訂定名目利率R=re+πe(e:expected，預期的)→實現的（realized）或實際的(actual)r=R-π＝re+πe-π，Sorreifπeπr=reifπe=πrreifπeπCopyright©2004South-WesternCh24:Summary•HowtocalculateCPI?•HowtocalculateInflationrate?•CPIvs.GDPdeflator•Nominalinterestratevs.realinterestrate•實際的actualr=R-π，•R=re+πe(e:expected，預期的)•Possibler0?•PossiblerR?