中级宏观经济学Government-Debt课件

GovernmentDebt15Inthischapter,youwilllearn…关于美国政府债务的规模，与其他国家相比，是怎样的。度量预算赤字的问题。关于政府债务的传统的观点和李嘉图Ricardian的观点。其他的关于债务的观点。CHAPTER15GovernmentDebtIndebtednessoftheworld’sgovernmentsCountryGovDebt

(%ofGDP)CountryGovDebt

(%ofGDP)Japan159U.S.A.64Italy125Sweden62Greece108Finland53Belgium99Norway52France77Denmark50Portugal77Spain49Germany70U.K.47Austria69Ireland30Canada69Korea20Netherlands64Australia15CHAPTER15GovernmentDebtRatioofU.S.govtdebttoGDP00.20.40.60.811.21791181518391863188719111935195919832007RevolutionaryWarCivilWarWW1WW2IraqWarCHAPTER15GovernmentDebtTheU.S.experienceinrecentyears1980s早期到1990s早期debt-GDPratio:25.5%in1980,48.9%in1993duetoReagantaxcuts,increasesindefensespending&entitlements1990s早期到2000年$290bdeficitin1992,$236bsurplusin2000debt-GDPratiofellto32.5%in2000duetorapidgrowth,stockmarketboom,taxhikes从2001以来thereturnofhugedeficits,duetoBushtaxcuts,

2001recession,IraqwarCHAPTER15GovernmentDebtThetroublingfiscaloutlookTheU.S.populationisaging.Healthcarecostsarerising.SpendingonentitlementslikeSocialSecurityandMedicareisgrowing.Deficitsandthedebtareprojectedtosignificantlyincrease…CHAPTER15GovernmentDebtPercentofU.S.populationage65+Percentofpop.58111417202319501960197019801990200020102020203020402050actualprojectedCHAPTER15GovernmentDebtU.S.governmentspendingonMedicareandSocialSecurityPercentofGDP02468195019551960196519701975198019851990199520002005CHAPTER15GovernmentDebtCBOprojectedU.S.federalgovtdebtintwoscenariosPercentofGDP0501001502002503002005201020152020202520302035204020452050optimisticscenariopessimistic

scenarioCHAPTER15GovernmentDebtProblemsmeasuringthedeficit1. Inflation2. Capitalassets3. Uncountedliabilities4. ThebusinesscycleCHAPTER15GovernmentDebtMEASUREMENTPROBLEM1:

Inflation假设实际债务保持不变，这意味着azerorealdeficit.在该情况下thenominaldebtD

以通货膨胀率的速度增长:

D/D=orD=D

报告的赤字(nominal)是

D

，尽管实际赤字是零。

所以，从报告的赤字中减去D来修正通货膨胀的影响。CHAPTER15GovernmentDebtMEASUREMENTPROBLEM1:

Inflation修正通货膨胀对赤字的影响非常重要，特别是通货膨胀很高的时候。Example:In1979,

nominaldeficit=$28billion inflation=8.6% debt=$495billion

D=0.086$495b=$43b realdeficit=$28b$43b=$15bsurplusCHAPTER15GovernmentDebtMEASUREMENTPROBLEM2:

CapitalAssetsCurrently,deficit=changeindebtBetter,capitalbudgeting:

deficit=(changeindebt)(changeinassets)EX:Supposegovtsellsanofficebuildingandusestheproceedstopaydownthedebt.undercurrentsystem,deficitwouldfallundercapitalbudgeting,deficitunchanged,becausefallindebtisoffsetbyafallinassets.Problemw/capbudgeting:Determiningwhichgovtexpenditurescountascapitalexpenditures.CHAPTER15GovernmentDebtMEASUREMENTPROBLEM3:

UncountedliabilitiesCurrentmeasureofdeficitomitsimportantliabilitiesofthegovernment:futurepensionpaymentsowedto

currentgovtworkers.futureSocialSecuritypaymentscontingentliabilities,e.g.,coveringfederallyinsureddepositswhenbanksfail (Hardtoattachadollarvaluetocontingentliabilities,duetoinherentuncertainty.)CHAPTER15GovernmentDebtMEASUREMENTPROBLEM4:

ThebusinesscycleThedeficitvariesoverthebusinesscycleduetoautomaticstabilizers(unemploymentinsurance,theincometaxsystem).Thesearenotmeasurementerrors,butdomakeithardertojudgefiscalpolicystance.E.g.,isanobservedincreaseindeficit

duetoadownturnoranexpansionaryshift

infiscalpolicy?CHAPTER15GovernmentDebtMEASUREMENTPROBLEM4:

ThebusinesscycleSolution:cyclicallyadjustedbudgetdeficit

(aka“full-employmentdeficit”)–basedonestimatesofwhatgovtspending&revenueswouldbeifeconomywereatthenaturalratesofoutput&unemployment.CHAPTER15GovernmentDebtThecyclicalcontributiontothe

U.S.Federalbudget-120-80-4004080120196519701975198019851990199520002005billionsofcurrentdollarsCHAPTER15GovernmentDebtThebottomlineWemustexercisecare

wheninterpreting

thereporteddeficitfigures.CHAPTER15GovernmentDebtIsthegovtdebtreallyaproblem?考虑减税，减税导致政府债务相应地增加。Twoviewpoints:1. Traditionalview2. RicardianviewCHAPTER15GovernmentDebtThetraditionalviewShortrun:Y,uLongrun:Y

和u

回到自然失业率水平closedeconomy:r,Iopeneconomy:,NX

(orhighertradedeficit)Verylongrun:增长放缓，经济达到一个新的稳态，新的稳态人均收入水平下降了。CHAPTER15GovernmentDebtTheRicardianviewduetoDavidRicardo(1820),

morerecentlyadvancedbyRobertBarroAccordingtoRicardianequivalence,

政府用负债来支持减税对消费，国民储蓄，实际利息率，投资、净出口或者实际GDP没有影响。在短期内也如此CHAPTER15GovernmentDebtThelogicofRicardianEquivalence消费者是forward-looking,

知道现在的adebt-financedtaxcuttoday意味着未来税收的增加，在现值上等于税收的减少额。

减税不能改善消费者的福利，这样他们不会增加消费支出。然而，他们会将减税的部分全部储蓄起来，偿还未来的税收负债taxliability.结果:私人储蓄增加，公共储蓄下降，其数额相等，国民储蓄量不变。CHAPTER15GovernmentDebtProblemswithRicardianEquivalenceMyopia:不是说有的消费者都能看的那么长远，一些消费者会将减税看成是asawindfall.Borrowingconstraints:一些消费者无法通过借贷来最优化其消费，于是他们将花掉减税额ataxcut.Futuregenerations:如果消费者预计减税的偿还义务由下一代人承担，那么他们将增加消费，改善自己的福利。CHAPTER15GovernmentDebtEvidenceagainstRicardianEquivalence?Early1980s:

Reagantaxcuts增加了赤字.

国民储蓄下降，实际利息率上升。

美元汇率升值，NX

下降1992:

所得税扣缴税款减少Incometaxwithholdingreduced，刺激了经济Almosthalfofconsumersincreasedconsumption.Thisdelayedtaxesbutdidn’tmakeconsumersbetteroff.CHAPTER15GovernmentDebtEvidenceagainstRicardianEquivalence?ProponentsofR.E.arguethattheReagantaxcutsdidnotprovideafairtestofR.E.Consumersmayhaveexpectedthedebttoberepaidwithfuturespendingcutsinsteadoffuturetaxhikes.Privatesavingmayhavefallenforreasonsotherthanthetaxcut,suchasoptimismabouttheeconomy.Becausethedataissubjecttodifferentinterpretations,bothviewsofgovtdebtsurvive.CHAPTER15GovernmentDebtOTHERPERSPECTIVES:Balancedbudgetsvs.optimalfiscalpolicySomepoliticianshaveproposedamendingtheU.S.Constitutiontorequirebalancedfederalgovtbudgeteveryyear.Manyeconomistsrejectthisproposal,arguingthatdeficitshouldbeusedtostabilizeoutput&employmentsmoothtaxesinthefaceoffluctuatingincomeredistributeincomeacrossgenerationswhenappropriateCHAPTER15GovernmentDebtOTHERPERSPECTIVES:

FiscaleffectsonmonetarypolicyGovtdeficitsmaybefinancedbyprintingmoneyAhighgovtdebtmaybeanincentiveforpolicymakerstocreateinflation(toreducerealvalueofdebtatexpenseofbondholders)Fortunately:littleevidencethatthelinkbetweenfiscalandmonetarypolicyisimportantmostgovernmentsknowthefollyofcreatinginflationmostcentralbankshave(atleastsome)politicalindependencefromfiscalpolicymakersCHAPTER15GovernmentDebtOTHERPERSPECTIVES:

Debtandpolitics“Fiscalpolicyisnotmadebyangels…”

–GregMankiw,p.449Somedonottrustpolicymakerswithdeficitspending.Theyarguethatpolicymakersdonotworryabouttruecostsoftheirspending,sinceburdenfallsonfuturetaxpayerssincefuturetaxpayerscannotparticipateinthedecisionprocess,theirinterestsmaynotbetakenintoaccountThisisanotherreasonfortheproposalsforabalancedbudgetamendment(discussedabove).CHAPTER15GovernmentDebtOTHERPERSPECTIVES:

InternationaldimensionsGovtbudgetdeficitscanleadtotradedeficits,whichmustbefinancedbyborrowingfromabroad.Largegovtdebtmayincreasetheriskofcapitalflight,asforeigninvestorsmayperceiveagreaterriskofdefault.Largedebtmayreduceacountry’spoliticalcloutininternationalaffairs.CHAPTER15GovernmentDebtCASESTUDY:

Inflation-indexedTreasurybondsStartingin1997,theU.S.TreasuryissuedbondswithreturnsindexedtotheCPI.Benefits:Removesinflationrisk,theriskthatinflation

–andhencerealinterestrate–willturnoutdifferentthanexpected.Mayencourageprivatesectortoissue

inflation-adjustedbonds.Providesawaytoinfertheexpectedrateofinflation…CHAPTER15GovernmentDebtCASESTUDY:

Inflation-indexedTreasurybonds01234562003-01-032003-06-272003-12-192004-06-112004-12-032005-05-272005-11-182006-05-12percent(annualrate)rateonnon-indexedbondimpliedexpectedinflationraterateonindexedbondCHAPTER15GovernmentDebtChapterSummary1. RelativetoGDP,theU.S.government’sdebtismoderatecomparedtoothercountries2. Standardfiguresonthedeficitareimperfectmeasuresoffiscalpolicybecausetheyarenotcorrectedforinflationdonotaccountforchangesingovtassetsomitsomeliabilities(e.g.,futurepensionpaymentstocurrentworkers)donotaccountforeffectsofbusinesscyclesCHAPTER15GovernmentDebtslide31CHAPTER15GovernmentDebtChapterSummary3. Inthetraditionalview,adebt-financedtaxcutincreasesconsumptionandreducesnationalsaving.Inaclosedeconomy,thisleadstohigherinterestrates,lowerinvestment,andalowerlong-runstandardofliving.Inanopeneconomy,itcausesanexchangerateappreciation,afallinnetexports(orincreaseinthetradedeficit).4. TheRicardianviewholdsthatdebt-financedtaxcutsdonotaffectconsumptionornationalsaving,andthereforedonotaffectinterestrates,investment,ornetexports.CHAPTER15GovernmentDebtslide32CHAPTER15GovernmentDebtChapterSummary5. Mosteconomistsopposeastrictbalancedbudgetrule,asitwouldhindertheuseoffiscalpolicytostabilizeoutput,smoothtaxes,orredistributethetaxburdenacrossgenerations.6. Governmentdebtcanhaveothereffects:mayleadtoinflationpoliticianscanshiftburdenoftaxesfromcurrenttofuturegenerationsmayreducecountry’spoliticalcloutininternationalaffairsorscareforeigninvestorsintopullingtheircapitaloutofthecountryCHAPTER15GovernmentDebtslide33CHAPTER15GovernmentDebtCHAPTER13AggregateSupply相同的政策在不同时期的不同结果：1963年肯尼迪政府的减税计划。1963年，失业率达到5.5％．（经济中有过剩的生产能力）实施减税计划。1965年失业率下降到4．4％，在60年代余下的年份保持在4％以下．实际GDP在1964-1966以超常的5.5％增长．通货膨胀率保持在较低水平。1968年，美国的失业率降低到了3％。1969年刺激内需的政策（减税、战争、大规模社会保障计划）。加剧了通货膨胀，甚至在1970年和1971年，失业率和物价水平同时上升，回到了1963年的水平。到1979年，失业率到了1961年的6％，通货膨胀率却达到了8％以上。实际GDP增长缓慢。CHAPTER15GovernmentDebt学习目的三种总供给模型：短期中产出与价格水平是正相关thePhillips曲线表明通货膨胀与失业在短期内是此消彼长（trade-off）的关系CHAPTER15GovernmentDebt三种总供给模型黏性工资模型不完全信息模型黏性价格模型以上所有的三个模型表明短期供给曲线为:naturalrateofoutputapositiveparametertheexpectedpriceleveltheactualpricelevelagg.

outputCHAPTER15GovernmentDebtThesticky-wagemodel假定在企业和工人发现物价水平发生变化之前，他们鉴订劳动合约，名义工资固定不变。根据目标实际工资和预期价格水平来确定名义工资W:TargetrealwageCHAPTER15GovernmentDebt黏性工资模型如果现实情况如下这样失业和产出在自然率水平实际工资低于目标水平，企业雇佣更多的工人，产出高于自然率水平实际工资超过目标水平，企业雇佣更少的工人，产出低于自然率水平CHAPTER15GovernmentDebt假定：就业量由企业对劳动力需求决定。CHAPTER15GovernmentDebt黏性工资模型意味着实际工资是反周期的（counter-cyclical）。实际工资与经济周期过程中的产出变化方向是相反的:在经济繁荣时期，当P

上升,实际工资应当下降.在经济衰退时期，当P

下降,实际工资应当上升.这一预言在现实世界里面并没有实现。CHAPTER15GovernmentDebt实际工资的周期性表现PercentagechangeinrealwagePercentagechangeinrealGDP1982197519931992196019961999199719981979197019801991197419901984200019721965-3-2-101237865443210-1-2-3-4-5CHAPTER15GovernmentDebtTheimperfect-informationmodel假设:所有的工资和价格都是完全伸缩性的；所有的市场是出清的。每个供给者生产一种产品，并消费许多产品.每个供给者知道他生产的产品的名义价格，但是不知道总体物价水平CHAPTER15GovernmentDebtTheimperfect-informationmodel每一产品的供给依赖其相对价格：该产品的名义价格／总体价格水平.供给者做出生产决策，不知道其产品的相对价格，只能用theexpectedpricelevel,Pe.假设P

提高，但是Pe

没有（未预期到）这样供给者会认为其产品相对价格会上升，他会生产更多.很多生产者都有这样的想法，一旦P

上升超过Pe，Y

将上升。CHAPTER15GovernmentDebtThesticky-pricemodel黏性价格的原因:企业和客户之间的长期合约菜单成本企业不希望经常变化价格而使得客户不悦。假设:企业决定其产品价格

(e.g.asinmonopolisticcompetition)思想：价格宣布之后，一些企业根据经济状况的变动迅速变化价格，还有一些企业暂时不调整价格，当价格低于宣布的价格时，它们的销售下降，引起企业削减生产和就业。CHAPTER15GovernmentDebtThesticky-pricemodel一个企业的产品或服务的合意价格是这里，

a>0.假设两类企业:价格是伸缩性的企业，确定价格如上式。价格是黏性的企业，根据其预期的经济状况事先宣布价格:CHAPTER15GovernmentDebtThesticky-pricemodel假设企业预期产出等于其自然率水平，这样为了推导出总供给曲线，我们首先要找到总价格水平的表达式.s

表示黏性价格企业的所占份额，这样，我们能够如下写出总体价格水平。CHAPTER15GovernmentDebtThesticky-pricemodel两边同时减去(1s

)P

:pricesetbyflexiblepricefirmspricesetbystickypricefirms两边同时除以s

:CHAPTER15GovernmentDebtThesticky-pricemodelPe越高

P越高如果企业预期高价格，这样企业会提前确定高价格.其他企业的反映：也会制定高价格.高Y

高P

当收入高，对产品的需求增加，伸缩性价格的企业会制定高价格.伸缩性价格的企业所占份额越大，s越小，Y对P的影响越大。

CHAPTER15GovernmentDebtThesticky-pricemodel最后,求解Y，推导出AS

方程:CHAPTER15GovernmentDebtThesticky-pricemodel与黏性工资模型相反，黏性价格模型意味着实际工资是亲周期的:假设总产出／收入下降，这样,企业发现其产品需求下降.黏性价格的企业减少生产，继而减少其劳动需求.劳动需求向左边移动，造成实际工资下降.CHAPTER15GovernmentDebt总结与含义三个总供给模型中的每一个模型都包含SRAS曲线&方程总结的关系Y

PLRASSRASCHAPTER15GovernmentDebt总结与含义假设积极的AD

冲击，产出超过其自然率水平，P

超过人们的预期水平.Y

PLRASSRAS1SRAS2AD1AD2随着时间推移,

Pe

提高,

SRAS

向上移动并且

产出回到自然率水平.CHAPTER15GovernmentDebtInflation,Unemployment,andthePhillipsCurve菲利普斯曲线值得信赖吗？UnemploymentRate(percent)123456789100246810InflationRate(percentperyear)1973196619721971196119621963196719681969197019651964CHAPTER15GovernmentDebt菲利普斯曲线值得信赖吗？

123456789100246810UnemploymentRate(percent)InflationRate(percentperyear)1972197519811976197819791980197319741977CHAPTER15GovernmentDebt菲利普斯曲线值得信赖吗？

123456789100246810UnemploymentRate(percent)InflationRate(percentperyear)1980198119821984198619851979A1983B1987CCopyright©2004South-WesternCHAPTER15GovernmentDebtInflation,Unemployment,andthePhillipsCurveThePhillipscurve

表明：依赖于预期的通货膨胀率,ecyclicalunemployment:实际失业率与自然失业率的背离供给冲击,

这里，

>0是外生固定的.CHAPTER15GovernmentDebt从SRAS推导

thePhillipsCurveOkun’slawCHAPTER15GovernmentDebtThePhillipsCurve和SRASSRAS

曲线:

产出与未预期到的价格变化有关系Phillipscurve:

失业率与未预期到的通货膨胀率的变化有关系。CHAPTER15GovernmentDebtGraphingthePhillipscurve在短期,政策制定者们面临trade-offbetween

andu.

u

短期的PhillipsCurveCHAPTER15GovernmentDebt表明失业和通货膨胀在短期中是此消彼涨的。.如果政策制定者扩大总需求，能够降低失业，但是要以更高的通货膨胀为代价。如果政策制定者紧缩总需求，能够降低通货膨胀，但是是以更高的暂时失业为代价。CHAPTER15