財務英文畢業(yè)論文

TABLEOFCONTENTSINTRODUCTION 91.DEFINITIONOFINFLATION 102.HISTORYOFINFLATION 103.MODERNDAYMEANINGOFINFLATION 104.CONSUMERPRICEINDEX 115.INFLATIONRATE 126.CAUSESOFINFLATION 147.EFFECTSOFINFLATION 158.CONTROLLINGINFLATION 15CONCLUSION 16REFERENCES 20INTRODUCTIONThepurposeofthisprojectistoclearlydefineINFLATION,identifyitscausesandeffectsandthewaysofeffectivelycontrollingit.Thisassignmentisdesignedtoprovideclearunderstandingofwhatinflationis.Furthertheessaywilloutlinethecausesandeffectsofinflationintheeconomyasawholeandwillidentifymeasuresonhowthegovernmentcaninfluenceandeffectivecontrolinflationtotheadvantageofthestateeconomy.1.DEFINITIONOFINFLATIONInEconomics,Inflationisariseinthegenerallevelofpricesofgoodsandservicesineconomyoveraperiodoftime.(MichaelBurdaandCharlesWyplosz(1997),Macroeconomics:AEuropeantext,2nded.,p.579(Glossary)2.HISTORYOFINFLATIONTheoriginofInflationdatesbacktothetimewhengoldwasusedasthepurchasingmediumintradinggoods.Itisatermwhichwasreferredtoaconditionofcurrency.Itwasoriginallyreferredtoasthedevaluationofthecurrency.Thebestexampletoshowthisdevaluationiswhenarulerorakingcollectsgoldfromhispeopleandsubsequentlymeltthesedownthenmixitwithothersemi-preciousmetalssuchassilver,copperorleadtoincreasethecoinsincirculationwithouttheneedtoincreasetheamountofgoldtoproducethem.Andwhentherulerorkingadoptsthispractice,thesupplyofcoinsincirculationwouldincreasebutwillultimatelydecreasethevalueofthecoin.Oncethevalueofthecoindeclines,itwouldincreasethenumberofcoinsrequiredtoexchangeforgoodsorservices.ApplyingthebasicconceptoftheLawofSupplyandDemandinEconomics,thiswouldmeanthatasthevalueofacoindecreasesduetoageneroussupplyincirculation,thereisaproportionateincreaseinthenumberofcoinsrequiredinexchangeofgoodsorservicesAndalthoughthiswillincreasethemoneysupply,thevalueofthecoinisdecreased.Whentherelativevalueofthecoindecrease,theconsumerswouldrequiremorecoinstopurchaseandwouldexperienceapriceincreasewiththedeclineofthecoin’svalue.3.MODERNDAYMEANINGOFINFLATIONFormanyyearsinflationwasnotrelatedtopricebutratheraconditionofcurrencyasdescribedabove.Overtheyearsandwithmanyargumentsamongsteconomists,whatwasoncedescribedasamonetarycausenowisbeingdescribedasapriceoutcome.(MichaelF.Bryan,1997,OntheOriginandEvolution)Inthemodernday,weheardifferenttypesofinflation.Itisawordoftenusedsynonymouslywithpriceincrease.Intoday’seconomy,Inflationisdefinedasthesustainedriseoftheaveragepricelevelofacountryoveraperiodoftime.(/wiki/IB_Economics/Macroeconomics)4.CONSUMERPRICEINDEXTherateofinflationismeasuredbytheannualpercentageinthelevelofpricesasmeasuredbytheConsumerPriceIndex(CPI).(RobertHallandJohnTaylor(1986),Macroeconomics:Theory,Performance,andPolicy,page5.TheConsumerPriceIndexmeasurespricesofaselectionofgoodsorservicespurchasedbyatypicalcustomer.TheConsumerPriceIndexaimstomeasurehowconsumers’purchasingpowerisaffectedbyrisingprices.(Blanchardetal,1993,2000,2002)Itmeasurestheprocessofaselectionofgoodsandservicespurchasedbyatypicalconsumer.(Mankiw2002,p.

22-32)Householdexpendituresurveysareperformedwhichseekstomeasurewhatpeoplespendtheirmoneyontogetatypicalbasketofgoods.Thisbasketofgoodsisupdatedeachyeartotakeintoconsiderationchangesinexpenditure.Thebasketofgoodsgivesrelativeimportancetoeachdifferentitemandchangesinthepricesofgoodsorservicesmonthlyaremonitoredandcombinedintoasinglefigurewithusingweightsinthebasket.ThebelowisthetypicalbasketofgoodsandservicesforUKconsumers:(ConsumerPricesIndexandRetailPriceIndex:the2008BasketofGoodsandServices,NationalStatisticsOffice,2008)5.INFLATIONRATETheInflationrateisthepercentagerateofchangeofapriceindexovertime.(/wiki/Inflation_rate)ItiscalculatedusingtheInflationrateformula:

CPICurrent-CPIPrevious=CurrentInflationRate

CPIPrevious

CPIApril–September2008(FirstRelease:ConsumerPricesIndices,September2008p.1,NationalStatisticsOffice)ApplyingtheformulaofcalculatingtheInflationrateusingactualdatafromtheNationalStatisticsOffice,theresultinginflationrateoverthe3monthperiodfromApriltoJune2008is1%whichmeansthatthegenerallevelofpricesfortypicalUKconsumersroseapproximatelyby1%overathree-monthperiod.Andoverasix-monthperiod,ApriltoSeptember2008,Inflationratewasat2.51%whichis151%increasefromtheInflationratecalculatedinJune2008.ApriltoJune2008109.00-107.60=1.00%

107.60

ApriltoSeptember2008110.30-107.60=2.51%

107.60

Ingeneral,highorunpredictableinflationratesareharmfultotheeconomyasawhole.Theymakeitdifficultforcompaniestodevelopbudgetsandlong-termplansandthiscontributeinefficienciesinthemarket.Afterseveralandseriousdebatesthateconomistshadovertheperiodofyears,thereisanunderlyingagreementthatinthelongrunInflationisessentiallyamonetaryphenomenon.Incontrast,intheshorttermandmedium,itwillbeaffectedbythesupplyanddemandintheeconomy,takingintoconsiderationtheelasticityofwages,pricesandinterestrates.(FederalReserveBoard'ssemiannualMonetaryPolicyReporttotheCongressRoundtableIntroductorystatementbyJean-ClaudeTrichetonJuly1,2004)Themeasuredinflationrateatanypointintimewillbemadeupofanarrayofindividualpricechanges.Buttheamountofinflationintheeconomyisaboutmorethanjustthesumofallindividualpricechanges.Somethingmorefundamentaldeterminestheamountofinflationintheeconomy-whetheritis1%,10or100%.(http://www.bankofengland.co.uk/education/targettwopointzero/inflation/whatCausesInflation.html)6.CAUSESOFINFLATIONOneofthemostevidentunderlyingcausesoftheriseofinflationisgoingbacktothefundamentallawofeconomicswhichistheLawofsupplyanddemand.Whendemandincreaseabovewhatcompaniescanproduceatanormalleveltherewillbeanupwardspulloncostsandprices.Sotoproducemore,thecompaniesincreasetheirdemandforresourceswhichmayresultintheriseofproductioncostsandprices.Economistsgenerallyagreethathighratesofinflationandhyperinflationarecausedbyanexcessivegrowthofthemoneysupply.RobertBarroandVittorioGrilli(1994),EuropeanMacroeconomics,Ch.8,p.139,Fig.8.1)Viewsonwhichfactorsdeterminemoderateratesofinflationaremorevaried.Lowormoderateinflationmaybeattributedtofluctuationsinrealdemandforgoodsandservices,orchangesinavailablesuppliessuchasduringscarcities,aswellastogrowthinthemoneysupply.Theconsensusviewisthatasustainedperiodofinflationiscausedwhenmoneysupplyincreasesfasterthanthegrowthinproductivityintheeconomy.(Mankiw2002,pp.

81-107Abel&Bernanke2005,pp.

266-269)However,theultimatecauseofinflationcanbesaidtobethecentralbankswhichpermitsanincreaseinthemonetarysupply.(LudwigvonMises,TheTheoryofMoneyandCredit).Thebehaviorandactionofthecentralbanksdeterminewhetherinflationisallowedtoriseortobekeptlow.Inotherwords,whethertheyallowpricetoriseuncheckedbymonetarypolicy,orwhethercentralbanksseekstoinfluencetheamountofmoneyintheeconomybychangingtheinterestrates.(BankofEngland,2000-2009)7.EFFECTSOFINFLATIONAsInflationiscausedbyseveraldifferentfactors,italsohasiteffects.Inflationcontradictstheassumptionthatmoneyhasafixedrateandthatitisstable,thisdefeatstheconceptofhistoricalvalueasbasisofatraditionalaccounting.(Massone,1981a.p.6)Risinginflationaffectsthesalarydemandsofemployeeandpromptsforhighersalarieswiththeeffectoffuelinginflation.Andwithpricesofcommoditiesexpectedtoriseasaresultofinflation,peopletendtohoardtogetridofexcessmoniesbeforeitgetsdevaluedandcanbuylessergoods.Hoardingcreatesshortageinsupplywhichcausestheincreaseinthepricesofcommodityasdemandforthemincreasewiththeirscarcity.Thetaskofkeepingtherateofinflationlowisusuallygiventomonetaryauthoritieswhoestablishmonetarypolicy.Generallytodaythesemonetaryauthoritiesarethecentralbanksthatcontrolthesizeofthemoneysupplythroughthesettingofinterestrates,throughopenmarketoperations,andthroughthesettingofbankingreserverequirements.(BankofEngland,MonetaryPolicyFramework,2006)Anincreaseinthegenerallevelofpricesimpliesadecreaseinthepurchasingpowerofthecurrency.Thatis,whenthegenerallevelofpricesrises,eachmonetaryunitbuysfewergoodsandservices.(Bulkley,George(31981),"PersonalSavingsandAnticipatedInflation".TheEconomicJournal91(361):pp.124-135,/pss/2231702.Retrievedon18November2008)Theeffectofinflationisnotdistributedevenly,andasaconsequencetherearehiddencoststosomeandbenefitstoothersfromthisdecreaseinpurchasingpower.Forexample,withinflationlendersordepositorswhoarepaidafixedrateofinterestonloansordepositswilllosepurchasingpowerfromtheirinterestearnings,whiletheirborrowersbenefit.Individualsorinstitutionswithcashassetswillexperienceadeclineinthepurchasingpoweroftheirholdings.Increasesinpaymentstoworkersandpensionersoftenlagbehindinflation,especiallyforthosewithfixedpayments.(Taylor,Timothy,2008,PrinciplesofEconomics)Therealpurchasing-poweroffixedpaymentsiserodedbyinflationunlesstheyareinflation-adjustedtokeeptheirrealvaluesconstant.Inmanycountries,employmentcontracts,pensionbenefits,andgovernmententitlements(suchassocialsecurity)aretiedtoacost-of-livingindex,typicallytotheconsumerpriceindex.(Flanagan,Tammy,2006).Acost-of-livingallowance(COLA)adjustssalariesbasedonchangesinacost-of-livingindex.Salariesaretypicallyadjustedannually.(COLAWars".GovernmentExecutive.NationalJournalGroup)Theymayalsobetiedtoacost-of-livingindexthatvariesbygeographiclocationiftheemployeemoves.Annualescalationclausesinemploymentcontractscanspecifyretroactiveorfuturepercentageincreasesinworkerpaywhicharenottiedtoanyindex.Thesenegotiatedincreasesinpayarecolloquiallyreferredtoascost-of-livingadjustmentsorcost-of-livingincreasesbecauseoftheirsimilaritytoincreasestiedtoexternally-determinedindexes.Mosteconomistsandcompensationanalystswouldconsidertheideaofpredeterminedfuture"costoflivingincreases"tobemisleadingfortworeasons:(1)Formostrecentperiodsintheindustrializedworld,averagewageshaveincreasedfasterthanmostcalculatedcost-of-livingindexes,reflectingtheinfluenceofrisingproductivityandworkerbargainingpowerratherthansimplylivingcosts,and(2)mostcost-of-livingindexesarenotforward-looking,butinsteadcomparecurrentorhistoricaldata.Ingeneralwageandpricecontrolsareregardedasatemporaryandexceptionalmeasure,onlyeffectivewhencoupledwithpoliciesdesignedtoreducetheunderlyingcausesofinflationduringthewageandpricecontrolregime,forexample,winningthewarbeingfought.Theyoftenhaveperverseeffects,duetothedistortedsignalstheysendtothemarket.Artificiallylowpricesoftencauserationingandshortagesanddiscouragefutureinvestment,resultinginyetfurthershortages.Theusualeconomicanalysisisthatanyproductorservicethatisunder-pricedisoverconsumed.Forexample,iftheofficialpriceofbreadistoolow,therewillbetoolittlebreadatofficialprices,andtoolittleinvestmentinbreadmakingbythemarkettosatisfyfutureneeds,therebyexacerbatingtheprobleminthelongterm.8.CONTROLLINGINFLATIONAsInflationaffectstheeconomyasawholeandthattheultimatecauseofinflationarethecentralbanksandthemeasurestheyapply,theyarealsotheagencywhocanultimatelycontrolinflation.Thetaskofkeepingtherateofinflationlowisusuallygiventomonetaryauthoritieswhoestablishmonetarypolicy.Generallytodaythesemonetaryauthoritiesarethecentralbanksthatcontrolthesizeofthemoneysupplythroughthesettingofinterestrates,throughopenmarketoperations,andthroughthesettingofbankingreserverequirements.(Taylor,Timothy,PrinciplesofEconomics,2008)Monetarypolicyistheprocessbywhichthegovernment,centralbank,ormonetaryauthorityofacountrycontrols(i)thesupplyofmoney,(ii)availabilityofmoney,and(iii)costofmoneyorrateofinterest,inordertoattainasetofobjectivesorientedtowardsthegrowthandstabilityoftheeconomy(MonetaryPolicy,FederalReserveBoard,January3,2006)Monetarytheoryprovidesinsightintohowtocraftoptimalmonetarypolicy.Monetarypolicyisreferredtoaseitherbeinganexpansionarypolicy,oracontractionarypolicy,whereanexpansionarypolicyincreasesthetotalsupplyofmoneyintheeconomy,andaconcretionarypolicydecreasesthetotalmoneysupply.Expansionarypolicyistraditionallyusedtocombatunemploymentinarecessionbyloweringinterestrates,whileconcretionarypolicyinvolvesraisinginterestratesinordertocombatinflation.Monetarypolicyshouldbecontrastedwithfiscalpolicy,whichreferstogovernmentborrowing,spendingandtaxation.(B.M.Friedman"MonetaryPolicy,"InternationalEncyclopediaoftheSocial&BehavioralSciences,2001,pp.9976-9984)TheBankofEngland,beingthecentralbankoftheUnitedKingdommustformulateandimplementamonetarypolicyintheareasofmoney,bankingandcreditwiththemainaimofmaintainingpricesconducivetobalancedandstableeconomicgrowth.Inaddition,itmustpromoteandpreservemonetarystability.Thecentralbankinfluencesinterestratesbyexpandingorcontractingthemonetarybase,whichconsistsofcurrencyincirculationandbanks'reservesondepositatthecentralbank.Theprimarywaythatthecentralbankcanaffectthemonetarybaseisbyopenmarketoperationsorsalesandpurchasesofsecondhandgovernmentdebt,orbychangingthereserverequirements.Ifthecentralbankwishestolowerinterestrates,itpurchasesgovernmentdebt,therebyincreasingtheamountofcashincirculationorcreditingbanks'reserveaccounts.Alternatively,itcanlowertheinterestrateondiscountsoroverdrafts(loanstobankssecuredbysuitablecollateral,specifiedbythecentralbank).Iftheinterestrateonsuchtransactionsissufficientlylow,commercialbankscanborrowfromthecentralbanktomeetreserverequirementsandusetheadditionalliquiditytoexpandtheirbalancesheets,increasingthecreditavailabletotheeconomy.Loweringreserverequirementshasasimilareffect,freeingupfundsforbankstoincreaseloansorbuyotherprofitableassets.(/wiki/Monetary_policy)Acentralbankcanonlyoperateatrulyindependentmonetarypolicywhentheexchangerateisfloating.(ExchangeRates,TheLibraryofEconomicsandLibertyMarch31,2006)Iftheexchangerateispeggedormanagedinanyway,thecentralbankwillhavetopurchaseorsellforeignexchange.Thesetransactionsinforeignexchangewillhaveaneffectonthemonetarybaseanalogoustoopenmarketpurchasesandsalesofgovernmentdebt;ifthecentralbankbuysforeignexchange,themonetarybaseexpands,andviceversa.Buteveninthecaseofapurefloatingexchangerate,centralbanksandmonetaryauthoritiescanatbest"leanagainstthewind"inaworldwherecapitalismobile.Accordingly,themanagementoftheexchangeratewillinfluencedomesticmonetaryconditions.Inordertomaintainitsmonetarypolicytarget,thecentralbankwillhavetosterilizeoroffsetitsforeignexchangeoperations.Forexample,ifacentralbankbuysforeignexchange(tocounteractappreciationoftheexchangerate),basemoneywillincrease.Therefore,tosterilizethatincrease,thecentralbankmustalsosellgovernmentdebttocontractthemonetarybasebyanequalamount.Itfollowsthatturbulentactivityinforeignexchangemarketscancauseacentralbanktolosecontrolofdomesticmonetarypolicywhenitisalsomanagingtheexchangerate.Inthe1980s,manyeconomistsbegantobelievethatmakinganation'scentralbankindependentoftherestofexecutivegovernmentisthebestwaytoensureanoptimalmonetarypolicy,andthosecentralbankswhichdidnothaveindependencebegantogainit.Thisistoavoidovertmanipulationofthetoolsofmonetarypoliciestoeffectpoliticalgoals,suchasre-electingthecurrentgovernment.Independencetypicallymeansthatthemembersofthecommitteewhichconductsmonetarypolicyhavelong,fixedterms.Obviously,thisisasomewhatlimitedindependence.Inthe1990s,centralbanksbeganadoptingformal,publicinflationtargetswiththegoalofmakingtheoutcomes,ifnottheprocess,ofmonetarypolicymoretransparent.Inotherwords,acentralbankmayhaveaninflationtargetof2%foragivenyear,andifinflationturnsouttobe5%,thenthecentralbankwilltypicallyhavetosubmitanexplanation.TheBankofEnglandexemplifiesboththesetrends.ItbecameindependentofgovernmentthroughtheBankofEnglandAct1998andadoptedaninflationtargetof2.5%RPI(now2%ofCPI).Giventhecloseassociationbetweeninflationandoutputgrowth,theMonetaryPolicyCommitteeoftheBankofEnglandshouldformulateanypolicywhichincreasesoutputwhichwouldlikelyhaveafavorableimpactoninflation;inaddition,loweringofinterestrateswhichleadstoincreaseingrowthislikelytoleadadeclineintheratesofinflation.CONCLUSIONThedefinitionofinflationhasevolvedovertheyears,frombeingreferredtoasaconditionofcurrencyandmoney;itisnowusedtodescribethebehaviorofpricesinone’seconomy.Aseconomistsdebateoveritsmeaningandthemethodsbywhichtoquantifyandmeasureit,itremainstruethatInflationismostsignificantlyrelatedtodemandandsupply.Thatasdemandforacommodityorservicesinscarcityincreases,therewillbeaproportionateincreaseinthepricesinthepurchaseofthegoodsorservices.Therefore,toprotecttheeconomyfromsuddenshiftofpricesduetoseveralfactorstheremustbeatoolineffectivelycontrollinginflation.ThecentralbanksliketheBankofEnglandastheultimatecauseofinflationmustdevelopasoundmonetarypolicythatwouldbothcontrolaparticularpriceandinterestratestoeffectivelycontrolinflation.Todaytheprimarytoolforcontrollinginflationismonetarypolicy.Mostcentralbanksaretaskedwithkeepinginflationatalowlevel;normallytoatargetratearound2%to3%perannum,andwithinatargetedlowinflationrange,somewherefromabout2%to6%perannum.Whenweviewinflationinthisperceptive,itwouldbethezero-inflationobjectiveforthecentralbankwhichwillbecomeamoresensiblegoal.REFERENCESAbel&Bernanke2005,pp.

266-269Barro(1993),op.citBankofEngland,2000-2009BankofEngland,MonetaryPolicyFramework,2006Blanchard(2000),op.citBulkley,George(31981).PersonalSavingsandAnticipatedInflation.TheEconomicJournal91(361):pp.124-135FederalReserveBoard,MonetaryPolicy,January3,2006http://www.bankofengland.co.uk/education/targettwopointzero/inflation/whatCausesInflation.htmlJean-ClaudeTrichet,‘FederalReserveBoard'ssemiannualMonetaryPolicyReporttotheCongressRoundtableIntroductorystatement,’July1,2004LudwigvonMises,TheTheoryofMoneyandCredit,ISBN0-913966-70-3Seealso:JesusHuertadeSoto,"Money,BankCredit,andEconomicCycles",ISBN0-945466-39-4MichaelBurdaandCharlesWyplosz(1997),Macroeconomics:AEuropeantext,2nded.,p.579NationalJournalGroup,COLAWars,GovernmentExecutive.Retrievedon21November2008NationalStatisticsOffice,‘ConsumerPricesIndexandRetailPriceIndex:the2008BasketofGoodsandServices,’2008NationalStatisticsOffice,‘FirstRelease:ConsumerPricesIndices,‘September2008p.1PersonalSavingsandAnticipatedInflation.TheEconomicJournal91(361):pp.124-135RobertHallandJohnTaylor(1986),Macroeconomics:Theory,Performance,andPolicy,page5.ISBN039395398XRobertBarroandVittorioGrilli(1994),EuropeanMacroeconomics,Ch.Taylor,Timothy,2008,PrinciplesofEconomics,FreeloadPress,ISBN193078905TheLibraryofEconomicsandLiberty,ExchangeRates,March31,2006消費習慣對于消費行為的影響分析摘要:最近10年中國經濟快速發(fā)展，而且1996年至1999年，為了刺激消費，央行連連降息，但是通過對居民消費數據的實證檢驗，證明消費存在過度平滑特性，由此可見，消費對于收入增長、利率下降的刺激，反應并不敏感。如何解釋？本文從習慣形成理論出發(fā)，在理論與實證兩方面探討了消費習慣對消費行為的影響。在理論方面，從習慣形成出發(fā)對持久收入消費函數進行修正，通過對修正后的函數形式平滑特性的分析，認為消費中的習慣形成，減少消費變化的波動性，使得消費函數更加平滑。在實證檢驗方面，通過對最近10年不同收入等級的城鎮(zhèn)居民食品消費的面板數據的實證分析，印證了習慣形成消費函數的理論模型。以此為基礎，可以對中國居民消費數據的平滑特性做出解釋：消費習慣對消費行為的影響，使得消費者不會對收入增長、利率下調等外部因素的刺激做出即時的、充分的反應，而是傾向于在較長的時間內，以較小的幅度逐漸地對消費支出進行調整。關鍵詞：平滑特性；習慣形成；持久收入；面板數據目錄序言···································································································23一、習慣形成里問見解以與相關文獻綜述·········································24二、居民消費數據平滑性的證實分析················································25三、·消費習慣對居民消費行為的影響分析·······································26四、結論·····························································································33參考文獻·······················································································34附錄······························································································35序言最近10年中國經濟的增長非常迅速，人均GNP的平均增長率為8.47%。但是居民消費的增長卻相對平穩(wěn)，平均增長率為7.26%。而且為了刺激消費，拉動內需，從1996年5月以來，中國人民銀行在3年之內連續(xù)7次降息，并在1999年11月開征利息稅。雖然從理論角度而言，無論是收入增長還是利率降低都應對消費有明顯的提升作用，但是實際上即使在收入與利率因素共同作用的情況下，居民消費水平也沒有顯著的增加。關于這一結論，可以很直觀地從圖1中看到，相對于人均GNP而言，居民人均消費序列較為平滑。為什么消費沒有對收入以與利率的變化做出充分反應，而是表現得如此不敏感？關于這一問題的爭論，一度是宏觀經濟中的熱點，眾說紛紜。但是討論大多從外部因素著眼，強調收入分配、流動性約束以與金融市場的不完善對消費決策的作用。本文試圖從新的角度——消費者的自身特征——消費習慣的角度出發(fā)，從理論推導與實證檢驗兩方面探討消費習慣對消費行為的影響。本文大體可以五部分。第一部分是引言?？紤]到國內在消費習慣問題方面的相關研究比較少，所以在第二部分中首先對消費習慣形成理論進行簡單介紹，其次總結了近來國外在這方面研究的相關成果。在第三部分對中國居民消費的平滑特征進行實證檢驗。第四部分首先是進行理論分析，引入習慣因素，對持久收入的消費函數進行修正，并在此基礎上將修正之后的結果與經典的理論形式進行比較，分析消費函數的平滑特性。接著在城鎮(zhèn)居民食品消費的面板數據中對添加習慣因素的消費函數形式進行實一.習慣形成理論簡介以與相關文獻綜述1.習慣形成理論簡介1989年Campbell與Deaton在一篇著名的研究論文中對美國的季度消費數據進行研究之后指出，根據持久收入理論，消費者會根據他所期望的今后一生中的收入，而不僅僅是當前的收入決定消費水平，因此持久收入相對于當期收入而言，具有平滑消費的作用。但是即使如此，相對于持久收入理論的預期而言，實際的消費數據對于收入沖擊的反應表現得更加平滑，他們將其稱之為過度平滑（excesssmoothness）特性。習慣形成理論的發(fā)展是基于對消費數據中的過度平滑特性的探討。消費習慣形成理論與經典消費理論的區(qū)別在于偏好的時間不可分性（time—nonseparablity）。在經典消費理論中，偏好是時間可分的（time-separable）,也就是當期的效用水平僅由當期的消費水平決定；而習慣形成理論則認為偏好是時間可分的（time-nonseparable）,也就是當期的效用水平不僅依賴當前的消費支出狀況，而且與此前的支出水平（滯后消費）相關。之所以對效用假設進行如此變動是因為：心理學對人類行為的研究認為，持久的舒適會產生厭倦，但是刺激卻可以消除厭倦。與此對應，消費者會對消費水平的長久不變感到厭煩，；但是消費的增長卻可以帶來與愉悅，因而增加滿足感（參見Scitovsky等人，2004）。所以對于消費行為而言，存在一種追求消費增長的偏好，將這樣的行為傾向可以看作是個體的決策習慣，這就是習慣形成理論的出發(fā)點。如何將這種變化進行模型化處理？習慣形成理論引入有效消費（effectiveconsumption）的概念。與經典消費理論的區(qū)別在于：經典消費理論中是當期的消費水平決定當期的效用水平；而習慣形成理論中當期的效用水平取決于有效消費，就是利用滯后消費對當期消費進行調整。對于有效消費的定義有兩種常見的形式：和（參見Wendner，2003）。在習慣形成理論的研究中，對于這兩者通常并不進行嚴格的區(qū)分，而是根據研究的需要，選取一種有效消費的定義形式，與特定形式的效用函數結合，對問題進行分析。2、習慣形成理論的文獻綜述（1）國外文獻綜述習慣形成的純理論研究大致集中在以下兩方面：一是探討習慣強度與消費增長、儲蓄之間的關系（參見Smith,2002；Wendner,2003；Alessie與Lusardi，1997）；二是在習慣形成模型中討論貨幣政策、經濟增長等宏觀經濟問題（參見Fuhrer，2000；Carroll等人，2000）。習慣形成的實證研究一直存在較大爭議。Heaton（1993）對美國月度的總量消費數據（aggregateconsumptiondata）的檢驗認為習慣形成的特征不明顯，Dynan（2000）應用美國的食品消費的面板數據（paneldata）進行的實證分析發(fā)現消費中習慣的影響并不顯著。與此相反，Braun等人（1993）的檢驗確認了日本的總量消費數據中習慣形成的存在，Fuhrer（2000）對美國的總量數據使用VAR模型擬合，結果現實數據與理論模型得到較好地統(tǒng)一。究竟習慣形成模型是否顯著，消費中習慣的強度如何還需進一步深入探討。（2）國內文獻綜述國內在消費的習慣形成方面的研究相對滯后，明確地提出“習慣形成”這一概念的相關研究成果極為少見。龍志和等人（2002）以某省會城市1999-2001的食品消費的面板數據對消費習慣形成模型進行估計，認為存在顯著的習慣形成的特征。二、居民消費數據平滑特性的實證分析Campbell與Deaton(1989)對美國的消費數據進行研究之后，指出持久收入理論不足以解釋實際消費數據中的平滑特性。從直觀感覺，中國居民消費表現出平滑特性，對其進行實證分析，是否也會呈現過度平滑特征，得到和Campbell與Deaton的研究相同的結論？本文利用1952-2003年的人均GNP與居民人均消費水平之間的關系進行過度平滑性檢驗。由于人均收入在數據搜集上的困難，本文使用人均GNP代替人均收入水平進行檢驗。之所以這樣選擇是因為，根據1981-2003年城鎮(zhèn)人均可支配收入與農村居民人均純收入的相應數據與人均GNP的相關系數的計算結果認為，人均GNP與人均收入是高度相關的。人均GNP與城鎮(zhèn)居民人均可支配收入的相關系數是0.9980，與農村居民人均純收入的相關系數是0.9866。因此使用人均GNP代替人均收入進行相關檢驗。對人均GNP進行單位根檢驗（ADF），二階差分序列平穩(wěn)，人均GNP的自回歸移動平均（ARMA）的估計結果如下（括號中的值是t統(tǒng)計量）：（1）（-2.81）D.W.=1.99=26.93根據Campbell與Deaton對于消費平滑性的檢驗，如果居民消費行為與持久收入理論相吻合，則消費變化應該滿足下式（具體推導過程詳見附錄）：（2）對于利率，且，所以公式（2）右邊乘子的最小值是1.67，由公式（1）可以得到消費變化的標準差于收入沖擊標準差之間的關系為：，將收入沖擊的標準差（）代入，可以得到消費變化的最小標準差為45.07（=1.67*26.93），但是根據居民人均消費水平估計的消費變化的標準差為20.09，遠遠小于根據持久收入理論預期最小值。因而可以得出這樣的結論：中國的居民消費具有過度平滑的特性，因而持久收入理論不足以充分解釋消費的平滑特性。三、消費習慣對居民消費行為的影響分析1、習慣形成的消費函數模型既然持久收入理論不足以對現實消費數據的平滑特性進行很好的解釋，那么可以考慮從習慣形成的角度對消費的平滑特性進行分析。本文沿用Alessie與Lusardi（1997）的分析思路，在二次型效用函數中，求解受到習慣因素影響的消費函數的具體形式。時期有代表性的消費者跨期動態(tài)最優(yōu)化問題可以表述為：（3）效用函數的形式為二次型，且，。有效消費的形式為（）。是t期的有效消費，取決于當期消費與滯后一期的消費，表示習慣的強度，也就是滯后期消費對當期消費的影響程度。當=0時，本期的有效消費與滯后期消費完全不相關，也就是經典的消費函數形式。隨著的增加，滯后消費對當期消費的影響程度增加，增加消費支出的傾向更加明顯，因此習慣因素在消費函數中的作用越來越顯著。假設代表型消費者的生命周期是無限期的，面臨的約束條件為：（4）（5）其中為t期的財富，并且與是給定的。為貼現率，r是利率并假定不隨時間改變。將代入約束條件中可以得到：整理后得到（6）求解跨期最優(yōu)的消費函數形式，構造拉格朗日方程進行求解，則為簡化形式，不妨令得到（7）因為效用函數為二次型，可以得到（常數）將其代入公式（4）中，可以得到將有效消費的函數形式代入，化簡之后可以得到（8）時，令（9）所以消費函數的形式可以寫成：（10）為持久收入理論中消費函數的標準形式。由此可以看出，對于習慣強度而言，當=0時，就是持久收入理論消費函數的標準形式；時，消費可以看成是滯后消費與持久收入中消費函數的標準形式的線性組合。習慣因素對持久收入理論的修正結果，從直觀意義而言，由于消費函數中滯后消費的存在，當前收入變動時，相對于持久收入的消費函數的標準形式而言，變動幅度要小，消費時間序列更加平滑（或者過度平滑）。下面對于受到習慣因素影響的消費函數的平滑性進行具體分析。2、習慣形成的消費函數平滑特性分析對于收入沖擊，習慣形成對于持久收入理論的修正形式相對于經典理論是否使得消費變化更加平滑？下面將對這一問題進行細致的分析。不妨設收入是一階自回歸序列AR（1），，。若收入受到預期之外的因素產生沖擊，將其單位化為1，，對于收入的意外沖擊，消費的變化為：（11）（12）因為，代入公式（12）可得（13）將以上結果代入公式（11）中可以得到由此可以得到消費變化的標準差與收入沖擊標準差之間的關系為：（14）由公式（14）的結果進行分析可以得到，如果滯后消費不會對當期消費產生影響，也就是時，，就是持久收入理論預期的針對收入波動消費變化的標準差的形式（參見Campbell與Deaton，1989）；時，因為，所以相對于持久收入理論中消費變化對收入沖擊的反應，習慣因素的存在使得消費變化更加平滑或者過度平滑（消費變化的標準差要小于持久收入理論的預期，也就是），而且消費強度越大，消費的平滑性表現得越明顯（）。所以習慣因素對消費決策的影響是，消費者在進行消費跨期規(guī)劃時，傾向于適當降低當前消費，為以后的增長留有空間。當前的收入增長并不會立即反映到當期的消費中，而是會通過