宏观经济学课件

宏观经济学-导论一、宏观经济学与微观经济学1、微观与宏观的界定微观经济学是研究个别厂商与家庭在市场上如何扮演产品供给者、消费者和要素供给者等行为，这些供需行为如何决定个别物品、劳务的价格、数量；以及这些市场的机能与政府如何影响资源的配置。分析的目的是要了解资源的配置是否满足人们的要求。由于分析的焦点是“相对价格”的决定与影响，因此又称为价格理论。宏观经济学的主题是整个经济社会的综合行为，所讨论的是一些总量与平均量变数的决定与变动。在这些总量与平均量变量中，最主要的有国民所得、总就业量、失业率、平均工资、物价水平、物价上涨率、外汇收支与经济增长率等。这些课题都以国民所得为轴心，故宏观经济学又被称为“所得理论”。2、宏观经济理论的微观基础微观经济学以最优化行为为假设（效用最大化、利润最大化）宏观经济学则依赖学者对经济社会的观察，直接设定行为模式，如KNS主义中，认定所得增加诱使消费增加，但消费增加量低于所得增加量，这些被称为“基本心理法则”的行为模式，不同于微观经济学中的最优化假定。近年来，宏观经济学的发展方向之一是运用微观经济理论的立论基础，以“代表性经济决策单位”追求利润最大、效用最大或成本最小等原则，推导出储蓄、货币需求等宏观经济理论，文献中称之为“宏观经济理论的微观基础”。如理性预期学派等。3、微观经济学与宏观经济学是相辅相成的JimWellsusedtoownamanufacturingbusinessthatmadehighprecisioncomponentsforcomputergames.EveryJuly,Jimhadtodecidehowmanycomponentstoproducefortheupcomingholidayseason,andeveryyear,hehadsimplydoubledhisproduction.Sinceheneverhadanytroublemovingtheinventory,Jimdecidedtodothesamethingagain--eventhoughitmeanttakingoutabigshorttermloantofinancetheexpansion.JimWells’DecisionWhatJimWellsIgnoredUnfortunately,Jim’scollegestudiesneverincludedacourseinmacroeconomicssohemissedsomerathersignificantdangersigns.FEDERALRESERVEIndividualsGiveDollarstoFedSellBondstoPublicIndividualshavelessmoneytospendPossibleRecessionSomeDangerSignsMoreWarningSignsConsumerLessConfidence=SpendingRecessionaryImplications+Unemployment=Less SpendingMoreWarningSignsExpansionaryMonetaryPolicyJapaneseImportsIntoUSBecomeLessExpensiveValueofYenRelativetoDollarDecreaseinDemandForJim’sComputerComponentsDisasterStrikesByThanksgiving,Jimfoundhimselfsittingonahugeinventorythathecouldn’tgiveaway,andbyDecemberhewasunabletopayahugeloanthatwouldn’tgoaway.ByJune,hewasbankrupt.JimMeetsTeresaToday,Jimworksasaconsultant顾问foroneofhisoldJapanesecompetitorsduringthedayandstudiesmacroeconomicsatnightinanexecutiveMBAprogram.HesitsinthefrontrowofclassrightnexttoTeresa.Teresa利用银行贷款购买了一处住宅，贷款利率是浮动的。SomeWarningSignsSure,Teresafeltalittlenervousaboutchoosingthevariablerate,butthemortgagebankertoldhernottoworry.Rateshadbeenstableforoverthreeyearsnow,anditshouldn’tbeanyproblem.WhatTeresafailedtosee,however,werenumerouswarningsignsofgrowinginflationarypressures.InflationaryPressuresDemand-PullSideUnemploymentRateReachesEightYearLowBusinessesRaisePricesofGoodsSoldHigherDemandForGoodsInflationaryPressuresSupplyofGoods(CostPush)BadCoffeeCropWorld-widedroughtandfoodshortagesReductioninOilSupplyFallinValueoftheDollarSupplyDecreasesSupplyDecreasesProducersRaisePrices

PriceofImportsIncreaseDisasterStrikesWithintwoyears,interestrateshadclimbedintothedoubledigits,andTeresacouldnolongeraffordherskyrocketingmortgagepayments.Withtheclimbininterestrates,theeconomyplungedintoarecession--takingtherealestatemarketdownwithit.Teresatriedtosellherhouseattheoriginalprice,butfinally,sheunloadeditfor$25,000lessthansheboughtitfor–losingeverycentofherequity.二、宏观经济问题1、国内问题InflationUnemploymentTheRateofEconomicGrowthMovementsintheBusinessCycle2、国际问题外汇收支平衡贸易发展与汇率MacroProblem#1:InflationDefinedasanupwardmovementofpricesfromoneyeartothenext.MeasuredbythepercentagechangeinpriceindicessuchastheConsumerPriceIndex,theProducerPriceIndex,ortheso-calledGDPdeflator.SomeInflationIndicesTheProducerPriceIndexisbasedonanumberofimportantrawmaterials.TheConsumerPriceIndexor“CPI”iscalculatedbypricingabasketofgoodsandservicespurchasedbyatypicalhousehold.ConsumerPriceIndexInflationAveraged3.4percentayear.Source:U.S.DepartmentofLabor14percentin1947Minus10percentin1932IncreaseinourPaychecksOurpurchasingpowerdeclinesTheCruelestTaxInflation(PricesofGoods)isgreaterthan生活优裕成本指数《福布斯》杂志有时会公布一个以巨富为考查目标的通货膨胀指数，叫“生活优裕成本指数”。具体数据见下表，同时列出了在1990~1991年间的增长率(平均增幅3.5%)，这是《福布斯》杂志计算这一指数5年来得出的最小增幅，在同一时期，消费者价格指数增加了4.4%。1991年价格（美元）90~91年增幅衣着：套装15000平跟船鞋29514娱乐：宴会（容纳40人，罗杰威尔斯餐厅）50400歌剧（两张演出季节票大都会歌剧院，周六晚包厢）22509食物鱼子酱（贝鲁佳。马罗索尔牌，1公升）14780香槟（多姆。佩里格农牌，一箱）9477交通费用飞机（李尔35A,标准设施，乘员10人）46250005直升机（西克尔斯机S-76，商务型）63000005汽车（劳斯莱斯“银色幽灵”）1517008MacroProblem#2:UnemploymentTheunemploymentrateismeasuredasthenumberofunemployedpersonsdividedbythenumberofpeopleinthelaborforce.UnemploymentRateSince1900Percentageoflaborforceunemployed19301990Year19401950196019701980302010192019001910AverageunemploymentActualunemploymentKindsofUnemploymentIntalkingaboutunemployment,economistsdistinguishbetweenthreekinds:frictional,cyclical,andstructural.磨察性失业、周期性失业、结构性失业。FrictionalUnemploymentFrictionalunemploymentistheleastofthemacroeconomist’sworries.Itoccursasanaturalpartofthejob-seekingprocessaspeoplequittheirjobsjustlongenoughtolookforandfindanotherone.CyclicalUnemploymentCyclicalunemploymentisamuchmoreseriousproblem.Itoccurswhentheeconomydipsintoarecession.Itisthistypeofunemploymentthatmacroeconomistshavehistoricallyspentmostoftheirtimetryingtosolve.StructuralUnemploymentStructuralunemploymentoccurswhenachangeintechnologymakessomeone’sjoborjobskillsobsolete过时、陈旧.MacroProblem#3:

TheRateofEconomicGrowthMeasuredbygrowthintheGrossDomesticProductor“GDP.”GDPisdefinedasthemarketvalueofallthefinalgoodsandservicesproducedinacountryinagivenyear.EconomistshavetwowaysofmeasuringGDP,the“flow-of-cost”or“income”approachandthe“flowofproduct”or“expenditures”approach.（还存在一个生产法或者增值法）ConsumptionexpendituresbyhouseholdsplusInvestmentexpendituresbybusinessesplusGovernmentpurchasesofgoodsandservicesplusNetexports=totalexports-totalimports=GDPFlowofproduct,orexpenditures,approachConsumptionexpendituresbyhouseholdsplusInvestmentexpendituresbybusinessesplusGovernmentpurchasesofgoodsandservicesplusNetexportsWagesplusRentsplusInterestplusProfitsFlowofcost,orincome,approach=GDP=Flowofproduct,orexpenditures,approachActualvs.PotentialGDPActualGDPrepresentswhatweareproducing.PotentialGDPrepresentsthemaximumamounttheeconomycanproducewithoutcausinginflation.WhenactualGDPislessthanpotentialGDP,weareintherecessionaryrangeoftheeconomy.WhenactualGDPisabovepotentialGDP,werunthestrongriskofinflation.PotentialGDPGDPgap“Negative”GDPgapActualGDP1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 1996800075007000650060005500500045004000GDP(billionsof1992dollars)UnemploymentRate1976 1978 1980 1982 1984 1986 1988 1990 1992 1994 19961086420Unemployment(percentofcivilianlaborforce)Nominalvs.RealGDPNominalGDPismeasuredinactualmarketprices.RealGDPisnominalGDPadjustedforinflation.Moreover,whenwedividenominalGDPbyrealGDP,weobtaintheGDPdeflator-anothervaluableinflationindex.OutputGrowthGDPisthebestwidelyavailablemeasureofthelevelandgrowthofoutputintheeconomy.U.S.RealGDP,1929-1994193019905,000YearRealGDP(billionsofdollars,1987prices)TheGreatDepressionVietnamWarFirstoilshockTightMoneySupply-sidetaxcutsJoblessRecoveryWorldWarIIPostwardemobilizationDuringthoseperiods,realandnominalGDPweremovinginoppositedirections.ThispointunderscoreswhyitissoimportanttofocusonrealGDPasthebestmeasureofgrowth.人类发展与国内生产总值经济学家们通常以一个国家的经济的绝对数或者人均规模来排列座次，实际上经济规模本身并不能反映人口生活标准的许多重要因素，因此不同团体已经建议用其他一些指标来取代GDP或者人均GDP，按照环境、医疗保健普及情况、读写能力以及期望寿命等因素变化做出相应调整。联合国发展计划署提供了替代指标的一个实例，称为人类发展指数。该指数综合考虑了期望寿命、读写能力以及平均收入的购买力。按照人均GDP计算，美国是世界上最富有的国家，但就HDI而言，美国落后于17个国家。以HDI计算的世界上最贫穷的两个国家是尼日尔和马里，那里的期望寿命只有45岁，识字率只有20%。但是这种计算方法也有缺陷，如无法准确确定不同指标的权重等。产出计算是困难的GDP是一个估计值，它是将一个经济里数以百万计的各种商品和劳务加起来得出的一个总和。但是计算这一数据会遇到一些难题。衡量质量的改变衡量政府的服务地下经济外部成本问题分配问题的重要性休闲的价值统计学问题的重要性MacroProblem#4:BusinessCyclesCloselyrelatedtotheissueofeconomicgrowthandrealGDPasameasureofsuchgrowthistheproblemof“businesscycles.”ThetermbusinesscyclereferstotherecurrentupsanddownsinrealGDPoverseveralyears.TimeLevelofbusinessactivityGrowthTrendTroughTroughPeakPeakRecessionRecessionRecoveryRecoveryDoBusinessCyclesExistAcentralconcernofmacroeconomistsistodeterminewhetherabusinesscycleexistsand,ifso,whataretheforcesbehindit.Moreimportantly,bothmacroeconomistsandthepoliticalleaderstheymayservewanttoknowwhatmacroeconomicpoliciesmaybeusedtocontrolorharness治理thebusinesscycle.AtTheSameTimeAcentralconcernofbusinessistodeterminewhethertheeconomyisgoingintoacontractionorexpansion--withacorrectguessbeingthedifferencebetweenabigprofitorabigloss.图1953-2003年中国GDP增长率的波动曲线

三、政府在宏观经济中的角色政府角色的演变（经济自由主义、国家干预、混合经济、计划经济体制、转型经济）政府角色：预算、立法、公营事业四、宏观经济学的产生与发展古典经济学KNS主义货币主义、新古典经济学新增长与新KNS主义WhyHistoryisImportantTheGreatDepressionStagnationofthe1950’sStagflationofthe1970’sTheJoblessRecoveryofthe1990’sFEDERALRESERVEEvolutionofMonetaryPolicyOverTimeEvolutionofFiscalPolicy(GovernmentSpending)OverTimeWhatWe’llDiscoverWe’llalsoseethatnewmacroeconomictheorieshaveemergedinresponsetothisincreasingcomplexityatkeyturningpointsintheworld’seconomichistory:Keynesianisminthe1930sMonetarisminthe1970sSupplySideeconomicsinthe1980sandNewClassicaleconomicsinthe1990s.宏观经济学发展史ClassicalEconomicsDatesbacktothelate1700s.RootedinthelaissezfairewritingsofAdamSmith,DavidRicardo,andJeanBaptisteSay.ClassicalEconomicsUnemploymentisanaturalpartofthebusinesscycle.Theeconomyisself-correcting.Mostimportant,thereisnoneedforthegovernmenttointervene.TheClassicalEconomists

MeettheGreatDepressionTheGreatDepressionThestockmarketcrashesin1929.GrossDomesticProductfellbyalmostathirdbetween1929and1933.25%oftheworkforcewasunemployed.Businessinvestmentfellfromabout$16billionin1929to$1billionby1933.TheBirthofKeynesianEconomicsTheKeynesianViewJohnMaynardKeynesflatlyrejectedtheClassicalnotionofaself-correctingeconomyandwarnedthatpatientlywaitingfortheeventualrecoverywasfruitlessbecause“inthelongrun,we’realldead.”TheKeynesianViewKeynesbelievedthatundercertaincircumstances,theeconomywouldnotnaturallyrebound反弹butsimplystagnate淤塞or,evenworse,fallintoadeathspiral漩涡.TheKeynesianCureToKeynes,theonlywaytogettheeconomymovingagainwastoprime注入theeconomicpump泵withincreasedgovernmentexpenditures.Thus,fiscalpolicywasbornandtheKeynesianprescriptionbecametheunderlyingofFranklinDelanoRoosevelt’sNewDeal.TheKennedyTaxCutIn1962,HellerrecommendedtoKennedythatthePresidentadvocatealargetaxcuttostimulatethesluggish偷懒的缓慢的economy.Congresseventuallyagreed,andthisKeynesiantaxcuthelpedmakethe1960soneofthemostprosperous繁荣decadesinAmerica.TheFoundationofStagflationThisfiscalstimuluslaidthefoundationfortheemergenceofstagflation–simultaneoushighinflationandhighunemployment.TheRootsofStagflationThestagflationproblemhaditrootsinPresidentLyndonJohnson’sstubbornness顽固的.TheRootsofStagflationInthelate1960s,againstthestrongadviceofhiseconomicadvisors,JohnsonincreasedexpendituresontheVietnamWarbutrefusedtocutspendingonhisGreatSocietysocialwelfareprograms.Thisrefusalhelpedspawnavirulent剧毒的种子“demandpull”inflation.Demand-PullInflationTheessenceofdemand-pullinflationis“toomuchMoneychasingtoofewgoods,”andthatexactlywhathappenedwhentheU.S.triedtofinanceboth“gunsandbutter”--boththeVietnamWarandtheGreatSociety.Demand-PullInflationPricelevelRealGDPPQEPQADASE'P'Q'AD'PotentialOutputCost-PushInflationCost-pushorsupplysideinflationoccurswhenfactorssuchasrapidincreasesinrawmaterialpricesorwageincreasesdriveupproductioncosts.Thiscanhappenasaresultofso-called“supplyshocks”suchasthoseexperiencedintheearly1970s.Duringthisperiodsuchshocksincludedcropfailures,aworldwidedrought,andaquadrupling四倍的oftheworldpriceofcrudeoil.Cost-PushInflationPricelevelRealGDPPQADASAS'PotentialOutputEPQE'P'Q'ABuddingParadox悖论的萌芽Priortothe1970s,economistsdidn’tbelieveyoucouldevenhavebothhighinflationandhighunemploymentatthesametime.Ifonewentup,theotherhadtogodown.Butthe1970sprovedeconomistswrongonthispointandlikewiseexposedKeynesianeconomicsasincapableofsolvingthenewstagnationproblem.TheKeynesianDilemmaUsingexpansionarypoliciestoreduceunemploymentsimplycreatedmoreinflationwhileusingcontractionarypoliciestocurb制止inflationonlydeepenedtherecession.ThatmeantthatthetraditionalKeynesiantoolscouldsolveonlyhalfofthestagflationproblematanyonetime--andonlybymakingtheotherhalfworse.TheRiseofMonetarismItwasthisinabilityofKeynesianeconomicstocopewith应对stagflationthatsetthestageforProfessorMiltonFriedman’sMonetaristchallengetowhathadbecometheKeynesianorthodoxy正统学说.Friedman’sMonetaristSchoolTheproblemsofbothinflationandrecessionmaybetracedtoonething--therateofgrowthofthemoneysupply.Inflationhappenswhenthegovernmentprintstoomuchmoneyandrecessionshappenwhenitprintstoolittle.TheMonetaristPerspectiveStagflationistheinevitable不可避免的resultofactivistfiscalandmonetarypoliciesthattrytopushtheeconomybeyonditsso-called“naturalrate”or,moretechnically,its“lowestsustainableunemploymentrate.”Thisnaturalrateofunemploymentisthelowestlevelofunemploymentthatcanbeattainedwithoutupwardpressureoninflation.AccordingtotheMonetarists,expansionaryattemptstogobeyondthislowestsustainableunemploymentratemayresultinshortrunspurts迸发ofgrowth.However,aftereachgrowthspurt,pricesandwagesriseanddragtheeconomybacktoitsnaturalrateofunemployment.SomeBitterMedicine苦方Overtime,thesefutile无意的无效的attemptstopushtheeconomybeyonditsnaturalrateleadtoanupwardinflationaryspiral.Inthissituation,Monetaristsbelievethattheonlywaytowringinflationandinflationaryexpectationsoutoftheeconomyistohavetheactualunemploymentrateriseabovethenaturalrateofunemploymentandthatmeansinducingarecession.InducingaRecessionThisisatleastoneinterpretationofwhattheFederalReservedidbeginningin1979undertheMonetaristbannerofsettingmonetarygrowthtargets.UnderChairmanPaulVolcker,theFedadoptedasharplycontractionarymonetarypolicyandinterestratessoared高扬提高toovertwentypercent.WhiletheFed’sbittermedicineworked,threeyearsofhardeconomictimesleftabittertasteinthemouthsoftheAmericanpeoplenowhungryforasweetermacroeconomiccurethaneithertheKeynesiansorMonetaristscouldoffer.Enterstageright:supplysideeconomics.ASweeterEconomicCureTheComingofRonaldReaganCutTaxesIncreaseGovernmentTaxRevenuesAcceleratetheRateofEconomicGrowthWITHOUTInducingInflationTheSupplySidePhilosophyOnthesurface,thesupplysideapproachlooksverysimilartothekindofKeynesiantaxcutprescribedinthe1960stostimulateasluggisheconomy.However,thesupplysidersviewedsuchtaxcutsfromaverydifferentbehavioralperspective.TheBehavioralDifferenceKeynesianismTaxCutIncreasedDemandforGoodsProducersmayincreasepricesPossibleInflationTheBehavioralDifferenceSupplySideEconomicsKeynesianismTaxCutIncreasedDemandforGoodsProducersmayincreasepricesPossibleInflationWorkerskeepmoreofwhattheyearnIndividualsworkharderandincreasetheirproductivityIncreasedOutputandEmploymentShiftstheSupplyCurveOutALowerBudgetDeficitThelossintaxrevenuesfromthetaxcutwouldbelessthanoffsetbytheincreaseintaxrevenuesfromincreasedeconomicgrowth.Thus,undersupplysideeconomics,thebudgetdeficitwouldactuallybereduced.TheEndResultUnfortunately,thatdidn’thappen.Whiletheeconomyboomedso,too,didAmerica’sbudgetdeficit.Andasthebudgetdeficitsoared,America’stradedeficitsoaredwithit.GeorgeBush’sBurdenTheseso-called“twindeficits”deeplyconcernedReagan’ssuccessorGeorgeBush,particularlyafterthebudgetdeficitjumpedover$200billionatthemidpointofhistermin1990,andtheeconomybegantoslideintorecession.ToKeynesians,thisrecessionwouldhavebeenaclearsignaltoengageinexpansionarypolicy.However,intheBushWhiteHouse,Reagan’sSupplySideadvisorshadbeensupplanted代替byso-called“NewClassicals.”

NewClassicalEconomicsNewClassicaleconomicsisbasedonthecontroversial有争议的theoryof“rationalexpectations.”Thistheorysaysthatifyouformyourexpectations“rationally,”youwilltakeintoaccountallavailableinformationincludingthefutureeffectsofactivistfiscalandmonetarypolicies.RationalExpectationsTheideabehindrationalexpectationsisthatsuchactivistpoliciesmightbeabletofoolpeopleforawhile.However,afterawhile,peoplewilllearnfromtheirexperiences,andthenyoucan’tfoolthematall.Thecentralpolicyimplicationofthisideaisprofound:rationalexpectationsrenderactivistfiscalandmonetarypoliciescompletelyineffectivesotheyshouldbeabandoned.理性预期使财政和货币政策完全失效SomeBadPoliticsWe’lltalkmoreaboutwhetherthistheoryisgoodeconomicsornotinalaterlesson,butitwasclearlybadpolitics–atleastforPresidentBush.Indeed,Bush’sNewClassicaladvisorsflatlyrejectedanyKeynesian“quickfix”tothedeepeningrecession.Instead,theycalledformore“stableandsystematic”policiesbasedonlongtermgoalsratherthanacontinuedrelianceon“short-sighteddiscretionary随意的reactions.”

TheEconomyStupidRestoredConfidenceWhatisperhapsmostinterestingaboutthistransitionofpoweristhatBillClintonactuallydidverylittletostimulatetheeconomy.Themerefact,however,thatClintonpromisedamoreactivistapproachhelpedrestorebusinessandconsumerconfidence.Atthesametime,CongressionalpassageofClinton’sdeficitreductionlegislationin1993sentWallStreetaclearsignalthathisAdministrationwasseriousaboutbudgetbalance.Together,thesefactorshelpedacceleratearecoverythathadalreadybegunbytheendofBush’sterm.ThesefactorsalsosetthestageforClinton’sremarkablyeasyre-electionin1996aswellasthelongesteconomicrecoveryinpeacetimehistory.OntheBrightSideAsweenteranewmillennium千年,thenation’smacroeconomicmagiciansappeartobeabletokeeptheunemploymentratewithinarelativelynarrowbandoftolerance容忍.Notehowtheamplitude振幅ofthebusinesscyclehasbeenconsiderablyreducedsincethewide-scaleapplicationofmacroeconomicpoliciesafterWorldWarII.Macroeconomics’BigQuestionsIsthereanywaytosimultaneouslystimulateeconomicgrowth,boostrealincome,andbalanceboththebudgetandtradedeficitsusingthetraditionaltoolsofmacroeconomics?

Orwillmacroeconomicshavetooncemoreevolvetosuccessfullysolvetheincreasinglycomplexproblemsbeforeus?Towardsthe21stCenturyThesearethemajormacroeconomicissuesnowfacedbyleadersaroundtheglobe.Wewillhelpyoutrytounderstandtheseimportantquestionsbyteachingyouthescience--andart--ofmacroeconomics.Economicsisnotsomethingtobememorizedbutrathersomethingtoconceptualize使概念化.Soasyoustudyit,thinkaboutittoo.Yourjobandyourbusinessmightjustdependuponit.InTheMeantimeTheWarringSchoolsofMacroeconomicsThePurposeOfThisLessonIstoexaminethreeofthemajorcontroversiesamongthefivemajorwarringschoolsofmacroeconomics.Wealsotakeamorein-depthlookatNewClassicaleconomics.NewClassicalEconomicsClassicalEconomicsKeynesianismSupplySideEconomicsMonetarismThreeImportantQuestionsWhatcausesinstabilityintheeconomy?Istheeconomyself-correcting?Shouldthegovernmentadhere追随torulesorusediscretioninsettingeconomicpolicy?Theso-called“NewClassical”isrootedintheClassicaleconomictradition.ItisimportantnotjustbecauseofthestronginfluenceithashadonrecentmacroeconomictheorybutalsobecauseNewClassicaleconomistsplayedapivotal中枢关键的roleinthe1992defeatofGeorgeBushbyBillClinton.NewClassicalEconomicsGeorgeBush’sPresidencyWhenBushassumedthepresidencyin1988,theeconomywassaddledwithbothhugebudgetandtradedeficits.Evenmoreofaproblemwasthatby1990,theeconomywasslidingintoarecession.Bush’sAdvisorsThisrecessionwouldhavebeenaclearsignaltoengageinexpansionarypolicytoanyred-blooded充满活力的Keynesian.IntheBushWhiteHouse,RonaldReagan’sSupplySideadvisorshadbeensupplanted排挤notbyKeynesiansbutratherbyanewbreedofeconomistssignificantlyinfluencedbyNewClassicalThinking.NewClassicaleconomicsisbasedonthecontroversialtheoryof“rationalexpectations.”ThistheorywasdevelopedbyNobelLaureateRobertLucasoftheUniversityofChicagoalongwithThomasSargentofStanfordandRobertBarroofHarvard.Itprovidesasharpcontrasttothenotionof“adaptiveexpectations”wepreviouslyintroducedinourlessononinflationandunemployment.NewClassicalEconomicsAdaptiveExpectationsYoumayrecallfromthatlessonthatwithadaptiveexpectations,peopletendtoassumethatinflationwillcontinuetobewhatitalreadyis.Forexample,ifinflationwas3%lastyear,adaptiveexpectationswillleadyoutopredictthatinflationwillbe3%nextyear.RationalExpectationsIncontrast,ifyouformyourexpectations“rationally,”youwilltakeintoaccountallavailableinformationincludingthefutureeffectsofactivistfiscalandmonetarypolicies.Theideabehindrationalexpectationsisthatsuchactivistpoliciesmightbeabletofoolpeopleforawhile.ThePolicyImplicationHowever,afterawhile,peoplewilllearnfromtheirexperiences,andthen,youcan’tfoolthematall.Thecentralpolicyimplicationofthisideaisprofound:rationalexpectationsrenderactivistfiscalandmonetarypoliciescompletelyineffectivesotheyshouldbeabandoned.AnExampleSupposetheFederalReserveundertakesexpansionarymonetarypolicytoclosearecessionarygap.Repeatedexperienceswithsuchactivistpolicyhavetaughtpeoplethatincreasesinthemoneysupplyfuelinflation.Toprotectthemselvesinaworldofrationalexpectations,businesseswillimmediatelyrespondtotheFed’sexpansionbyraisingprices,workerswilldemandhigherwages,andtheattemptedstimuluswillbecompletelyoffsetbythecontractionaryeffectsofinflation.AlternativelySupposethegovernmentundertakesexpansionaryfiscalpolicy.Peoplewithrationalexpectationswillrespondbyincreasingtheirsavingsandreducingconsumptionandtherebylikewiseoffsetanyexpansionaryeffect.

Theywilldothisbecausetheyknowthatalargerbudgetdeficitnowmeanshighertaxeslatersotheyprepareforthisfutureburdenbysavingmore.Suppose,then,wefirstassumeadaptiveexpectations,andthegovernmentundertakesexpansionarypolicytoincreaseoutputabovethefullemploymentrate.AGraphicalAnalysisRealOutputGeneralPriceLevelLRASY1ADASAP1Suppose,then,wefirstassumeadaptiveexpectations,andthegovernmentundertakesexpansionarypolicytoincreaseoutputabovethefullemploymentrate.AGraphicalAnalysisRealOutputGeneralPriceLevelLRASY1ADASAD1AY2BP2P1Theendresultisashortrunspurtofgrowthabovefullemploymentoutputfollowedbyareturntothenaturalrate--albeit尽管,atahigherpricelevelofP3.AGraphicalAnalysisRealOutputGeneralPriceLevelLRASY1ADASAD1AY2BP2AS1P3CP1AGraphicalAnalysisRealOutputGeneralPriceLevelLRASY1ADASAD1AP1Y2BP2AS2P3CWhattheNewClassicalschoolsaysisthatratherthantravelfromPointAtoPointBandbacktopointC,theeconomywillenjoynoshortrungrowthspurtatPointB.Instead,theeconomywillmoveinstantaneouslyfromPointAtoPointC,andtheonlyresultofthegovernment’sactivistpolicywillbehigherinflation.RationExpectations:AReviewNowthereareseveralthingstosayaboutrationalexpectationstheoryfrombothaneconomicandpoliticalperspective.ACritiqueCriticssaypeoplearenotassophisticatedintheireconomicthinkingasthetheoryrequiresandthereforeadjustmentswillnottakeplacewiththespeedtheyaresupposedto.Thiscriticismshouldnotdetract贬损fromthecentralpointofrationalexpectations,namely,thatpeople’sbehaviormaypartially,orperhapscompletely,counteractthegoalsofactivistfiscalandmonetarypolicies.WhatBushLearnedPoliticallyhowever,asGeorgeBushpainfullylearned,relyingonNewClassicaleconomicthinkingcanbehazardous风险危害toone’shealth.Indeed,PresidentBush’sNewClassicaladvisorsflatlyrejectedanyKeynesian“quickfix”toBush’sdeepeningrecession.WhatBushDidInstead,intheirEconomicReporttothePresident,theycalledformore“stableandsystematic”policiesbasedonlongtermgoalsratherthanacontinuedrelianceon“short-sighteddiscretionaryreactions.”TheClintonPromiseWhatisperhapsmostinterestingaboutthistransitionofpoweristhatBillClintonactuallydidverylittletostimulatetheeconomy.Themerefact,however,thatClintonpromisedamoreactivistapproachhelpedrestorebusinessandconsumerconfidence.WhatCongressDidCongressionalpassageofClinton’sdeficitreductionlegislationin1993sentWallStreetaclearsignalthathisAdministrationwasseriousaboutbudgetbalance.Thesefactorshelpedacceleratearecoveryth