GovernmentDebt15GovernmentDebt15Inthischapter,youwilllearn…關(guān)于美國政府債務的規(guī)模，與其他國家相比，是怎樣的。度量預算赤字的問題。關(guān)于政府債務的傳統(tǒng)的觀點和李嘉圖Ricardian的觀點。其他的關(guān)于債務的觀點。CHAPTER15GovernmentDebtInthischapter,youwilllearIndebtednessoftheworld’sgovernmentsCountryGovDebt

(%ofGDP)CountryGovDebt

(%ofGDP)Japan159U.S.A.64Italy125Sweden62Greece108Finland53Belgium99Norway52France77Denmark50Portugal77Spain49Germany70U.K.47Austria69Ireland30Canada69Korea20Netherlands64Australia15CHAPTER15GovernmentDebtIndebtednessoftheworld’sgoRatioofU.S.govtdebttoGDP00.20.40.60.811.21791181518391863188719111935195919832007RevolutionaryWarCivilWarWW1WW2IraqWarCHAPTER15GovernmentDebtRatioofU.S.govtdebttoGDPTheU.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從2001以來thereturnofhugedeficits,duetoBushtaxcuts,

2001recession,IraqwarCHAPTER15GovernmentDebtTheU.S.experienceinrecentThetroublingfiscaloutlookTheU.S.populationisaging.Healthcarecostsarerising.SpendingonentitlementslikeSocialSecurityandMedicareisgrowing.Deficitsandthedebtareprojectedtosignificantlyincrease…CHAPTER15GovernmentDebtThetroublingfiscaloutlookThPercentofU.S.populationage65+Percentofpop.58111417202319501960197019801990200020102020203020402050actualprojectedCHAPTER15GovernmentDebtPercentofU.S.populationageU.S.governmentspendingonMedicareandSocialSecurityPercentofGDP02468195019551960196519701975198019851990199520002005CHAPTER15GovernmentDebtU.S.governmentspendingonMeCBOprojectedU.S.federalgovtdebtintwoscenariosPercentofGDP0501001502002503002005201020152020202520302035204020452050optimisticscenariopessimistic

scenarioCHAPTER15GovernmentDebtCBOprojectedU.S.federalgovProblemsmeasuringthedeficit1. Inflation2. Capitalassets3. Uncountedliabilities4. ThebusinesscycleCHAPTER15GovernmentDebtProblemsmeasuringthedeficitMEASUREMENTPROBLEM1:

Inflation假設實際債務保持不變，這意味著azerorealdeficit.在該情況下thenominaldebtD

以通貨膨脹率的速度增長:

D/D=orD=D

報告的赤字(nominal)是

D

，盡管實際赤字是零。

所以，從報告的赤字中減去D來修正通貨膨脹的影響。CHAPTER15GovernmentDebtMEASUREMENTPROBLEM1:

InflaMEASUREMENTPROBLEM1:

Inflation修正通貨膨脹對赤字的影響非常重要，特別是通貨膨脹很高的時候。Example:In1979,

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

D=0.086$495b=$43b realdeficit=$28b$43b=$15bsurplusCHAPTER15GovernmentDebtMEASUREMENTPROBLEM1:

InflaMEASUREMENTPROBLEM2:

CapitalAssetsCurrently,deficit=changeindebtBetter,capitalbudgeting:

deficit=(changeindebt)(changeinassets)EX:Supposegovtsellsanofficebuildingandusestheproceedstopaydownthedebt.undercurrentsystem,deficitwouldfallundercapitalbudgeting,deficitunchanged,becausefallindebtisoffsetbyafallinassets.Problemw/capbudgeting:Determiningwhichgovtexpenditurescountascapitalexpenditures.CHAPTER15GovernmentDebtMEASUREMENTPROBLEM2:

CapitMEASUREMENTPROBLEM3:

UncountedliabilitiesCurrentmeasureofdeficitomitsimportantliabilitiesofthegovernment:futurepensionpaymentsowedto

currentgovtworkers.futureSocialSecuritypaymentscontingentliabilities,e.g.,coveringfederallyinsureddepositswhenbanksfail (Hardtoattachadollarvaluetocontingentliabilities,duetoinherentuncertainty.)CHAPTER15GovernmentDebtMEASUREMENTPROBLEM3:

UncouMEASUREMENTPROBLEM4:

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

duetoadownturnoranexpansionaryshift

infiscalpolicy?CHAPTER15GovernmentDebtMEASUREMENTPROBLEM4:

ThebMEASUREMENTPROBLEM4:

ThebusinesscycleSolution:cyclicallyadjustedbudgetdeficit

(aka“full-employmentdeficit”)–basedonestimatesofwhatgovtspending&revenueswouldbeifeconomywereatthenaturalratesofoutput&unemployment.CHAPTER15GovernmentDebtMEASUREMENTPROBLEM4:

ThebThecyclicalcontributiontothe

U.S.Federalbudget-120-80-4004080120196519701975198019851990199520002005billionsofcurrentdollarsCHAPTER15GovernmentDebtThecyclicalcontributiontotThebottomlineWemustexercisecare

wheninterpreting

thereporteddeficitfigures.CHAPTER15GovernmentDebtThebottomlineWemustexercisIsthegovtdebtreallyaproblem?考慮減稅，減稅導致政府債務相應地增加。Twoviewpoints:1. Traditionalview2. RicardianviewCHAPTER15GovernmentDebtIsthegovtdebtreallyaprobThetraditionalviewShortrun:Y,uLongrun:Y

和u

回到自然失業(yè)率水平closedeconomy:r,Iopeneconomy:,NX

(orhighertradedeficit)Verylongrun:增長放緩，經(jīng)濟達到一個新的穩(wěn)態(tài)，新的穩(wěn)態(tài)人均收入水平下降了。CHAPTER15GovernmentDebtThetraditionalviewShortrun:TheRicardianviewduetoDavidRicardo(1820),

morerecentlyadvancedbyRobertBarroAccordingtoRicardianequivalence,

政府用負債來支持減稅對消費，國民儲蓄，實際利息率，投資、凈出口或者實際GDP沒有影響。在短期內(nèi)也如此CHAPTER15GovernmentDebtTheRicardianviewduetoDavidThelogicofRicardianEquivalence消費者是forward-looking,

知道現(xiàn)在的adebt-financedtaxcuttoday意味著未來稅收的增加，在現(xiàn)值上等于稅收的減少額。

減稅不能改善消費者的福利，這樣他們不會增加消費支出。然而，他們會將減稅的部分全部儲蓄起來，償還未來的稅收負債taxliability.結(jié)果:私人儲蓄增加，公共儲蓄下降，其數(shù)額相等，國民儲蓄量不變。CHAPTER15GovernmentDebtThelogicofRicardianEquivalProblemswithRicardianEquivalenceMyopia:不是說有的消費者都能看的那么長遠，一些消費者會將減稅看成是asawindfall.Borrowingconstraints:一些消費者無法通過借貸來最優(yōu)化其消費，于是他們將花掉減稅額ataxcut.Futuregenerations:如果消費者預計減稅的償還義務由下一代人承擔，那么他們將增加消費，改善自己的福利。CHAPTER15GovernmentDebtProblemswithRicardianEquivaEvidenceagainstRicardianEquivalence?Early1980s:

Reagantaxcuts增加了赤字.

國民儲蓄下降，實際利息率上升。

美元匯率升值，NX

下降1992:

所得稅扣繳稅款減少Incometaxwithholdingreduced，刺激了經(jīng)濟Almosthalfofconsumersincreasedconsumption.Thisdelayedtaxesbutdidn’tmakeconsumersbetteroff.CHAPTER15GovernmentDebtEvidenceagainstRicardianEquEvidenceagainstRicardianEquivalence?ProponentsofR.E.arguethattheReagantaxcutsdidnotprovideafairtestofR.E.Consumersmayhaveexpectedthedebttoberepaidwithfuturespendingcutsinsteadoffuturetaxhikes.Privatesavingmayhavefallenforreasonsotherthanthetaxcut,suchasoptimismabouttheeconomy.Becausethedataissubjecttodifferentinterpretations,bothviewsofgovtdebtsurvive.CHAPTER15GovernmentDebtEvidenceagainstRicardianEquOTHERPERSPECTIVES:Balancedbudgetsvs.optimalfiscalpolicySomepoliticianshaveproposedamendingtheU.S.Constitutiontorequirebalancedfederalgovtbudgeteveryyear.Manyeconomistsrejectthisproposal,arguingthatdeficitshouldbeusedtostabilizeoutput&employmentsmoothtaxesinthefaceoffluctuatingincomeredistributeincomeacrossgenerationswhenappropriateCHAPTER15GovernmentDebtOTHERPERSPECTIVES:BalancedOTHERPERSPECTIVES:

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

FiscaleOTHERPERSPECTIVES:

Debtandpolitics“Fiscalpolicyisnotmadebyangels…”

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

DebtandOTHERPERSPECTIVES:

InternationaldimensionsGovtbudgetdeficitscanleadtotradedeficits,whichmustbefinancedbyborrowingfromabroad.Largegovtdebtmayincreasetheriskofcapitalflight,asforeigninvestorsmayperceiveagreaterriskofdefault.Largedebtmayreduceacountry’spoliticalcloutininternationalaffairs.CHAPTER15GovernmentDebtOTHERPERSPECTIVES:

InternatioCASESTUDY:

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

–andhencerealinterestrate–willturnoutdifferentthanexpected.Mayencourageprivatesectortoissue

inflation-adjustedbonds.Providesawaytoinfertheexpectedrateofinflation…CHAPTER15GovernmentDebtCASESTUDY:

Inflation-indexedCASESTUDY:

Inflation-indexedTreasurybonds01234562003-01-032003-06-272003-12-192004-06-112004-12-032005-05-272005-11-182006-05-12percent(annualrate)rateonnon-indexedbondimpliedexpectedinflationraterateonindexedbondCHAPTER15GovernmentDebtCASESTUDY:

Inflation-indexedChapterSummary1. RelativetoGDP,theU.S.government’sdebtismoderatecomparedtoothercountries2. Standardfiguresonthedeficitareimperfectmeasuresoffiscalpolicybecausetheyarenotcorrectedforinflationdonotaccountforchangesingovtassetsomitsomeliabilities(e.g.,futurepensionpaymentstocurrentworkers)donotaccountforeffectsofbusinesscyclesCHAPTER15GovernmentDebtslide31CHAPTER15GovernmentDebtChapterSummary1. RelativetoChapterSummary3. Inthetraditionalview,adebt-financedtaxcutincreasesconsumptionandreducesnationalsaving.Inaclosedeconomy,thisleadstohigherinterestrates,lowerinvestment,andalowerlong-runstandardofliving.Inanopeneconomy,itcausesanexchangerateappreciation,afallinnetexports(orincreaseinthetradedeficit).4. TheRicardianviewholdsthatdebt-financedtaxcutsdonotaffectconsumptionornationalsaving,andthereforedonotaffectinterestrates,investment,ornetexports.CHAPTER15GovernmentDebtslide32CHAPTER15GovernmentDebtChapterSummary3. InthetradiChapterSummary5. Mosteconomistsopposeastrictbalancedbudgetrule,asitwouldhindertheuseoffiscalpolicytostabilizeoutput,smoothtaxes,orredistributethetaxburdenacrossgenerations.6. Governmentdebtcanhaveothereffects:mayleadtoinflationpoliticianscanshiftburdenoftaxesfromcurrenttofuturegenerationsmayreducecountry’spoliticalcloutininternationalaffairsorscareforeigninvestorsintopullingtheircapitaloutofthecountryCHAPTER15GovernmentDebtslide33CHAPTER15GovernmentDebtChapterSummary5. MosteconomiCHAPTER13AggregateSupplyCHAPTER13相同的政策在不同時期的不同結(jié)果：1963年肯尼迪政府的減稅計劃。1963年，失業(yè)率達到5.5％．（經(jīng)濟中有過剩的生產(chǎn)能力）實施減稅計劃。1965年失業(yè)率下降到4．4％，在60年代余下的年份保持在4％以下．實際GDP在1964-1966以超常的5.5％增長．通貨膨脹率保持在較低水平。1968年，美國的失業(yè)率降低到了3％。1969年刺激內(nèi)需的政策（減稅、戰(zhàn)爭、大規(guī)模社會保障計劃）。加劇了通貨膨脹，甚至在1970年和1971年，失業(yè)率和物價水平同時上升，回到了1963年的水平。到1979年，失業(yè)率到了1961年的6％，通貨膨脹率卻達到了8％以上。實際GDP增長緩慢。CHAPTER15GovernmentDebt相同的政策在不同時期的不同結(jié)果：CHAPTER15G學習目的三種總供給模型：短期中產(chǎn)出與價格水平是正相關(guān)thePhillips曲線表明通貨膨脹與失業(yè)在短期內(nèi)是此消彼長（trade-off）的關(guān)系CHAPTER15GovernmentDebt學習目的三種總供給模型：短期中產(chǎn)出與價格水平是正相關(guān)CHAP三種總供給模型黏性工資模型不完全信息模型黏性價格模型以上所有的三個模型表明短期供給曲線為:naturalrateofoutputapositiveparametertheexpectedpriceleveltheactualpricelevelagg.

outputCHAPTER15GovernmentDebt三種總供給模型黏性工資模型naturalrateofoThesticky-wagemodel假定在企業(yè)和工人發(fā)現(xiàn)物價水平發(fā)生變化之前，他們鑒訂勞動合約，名義工資固定不變。根據(jù)目標實際工資和預期價格水平來確定名義工資W:TargetrealwageCHAPTER15GovernmentDebtThesticky-wagemodel假定在企業(yè)和工人發(fā)黏性工資模型如果現(xiàn)實情況如下這樣失業(yè)和產(chǎn)出在自然率水平實際工資低于目標水平，企業(yè)雇傭更多的工人，產(chǎn)出高于自然率水平實際工資超過目標水平，企業(yè)雇傭更少的工人，產(chǎn)出低于自然率水平CHAPTER15GovernmentDebt黏性工資模型如果現(xiàn)實情況如下這樣失業(yè)和產(chǎn)出在自然率水平實際工假定：就業(yè)量由企業(yè)對勞動力需求決定。CHAPTER15GovernmentDebt假定：就業(yè)量由企業(yè)對勞動力需求決定。CHAPTER15黏性工資模型意味著實際工資是反周期的（counter-cyclical）。實際工資與經(jīng)濟周期過程中的產(chǎn)出變化方向是相反的:在經(jīng)濟繁榮時期，當P

上升,實際工資應當下降.在經(jīng)濟衰退時期，當P

下降,實際工資應當上升.這一預言在現(xiàn)實世界里面并沒有實現(xiàn)。CHAPTER15GovernmentDebt黏性工資模型意味著實際工資是反周期的（counter-cyc實際工資的周期性表現(xiàn)PercentagechangeinrealwagePercentagechangeinrealGDP1982197519931992196019961999199719981979197019801991197419901984200019721965-3-2-101237865443210-1-2-3-4-5CHAPTER15GovernmentDebt實際工資的周期性表現(xiàn)PercentagechangeiTheimperfect-informationmodel假設:所有的工資和價格都是完全伸縮性的；所有的市場是出清的。每個供給者生產(chǎn)一種產(chǎn)品，并消費許多產(chǎn)品.每個供給者知道他生產(chǎn)的產(chǎn)品的名義價格，但是不知道總體物價水平CHAPTER15GovernmentDebtTheimperfect-informationmodeTheimperfect-informationmodel每一產(chǎn)品的供給依賴其相對價格：該產(chǎn)品的名義價格／總體價格水平.供給者做出生產(chǎn)決策，不知道其產(chǎn)品的相對價格，只能用theexpectedpricelevel,Pe.假設P

提高，但是Pe

沒有（未預期到）這樣供給者會認為其產(chǎn)品相對價格會上升，他會生產(chǎn)更多.很多生產(chǎn)者都有這樣的想法，一旦P

上升超過Pe，Y

將上升。CHAPTER15GovernmentDebtTheimperfect-informationmodeThesticky-pricemodel黏性價格的原因:企業(yè)和客戶之間的長期合約菜單成本企業(yè)不希望經(jīng)常變化價格而使得客戶不悅。假設:企業(yè)決定其產(chǎn)品價格

(e.g.asinmonopolisticcompetition)思想：價格宣布之后，一些企業(yè)根據(jù)經(jīng)濟狀況的變動迅速變化價格，還有一些企業(yè)暫時不調(diào)整價格，當價格低于宣布的價格時，它們的銷售下降，引起企業(yè)削減生產(chǎn)和就業(yè)。CHAPTER15GovernmentDebtThesticky-pricemodel黏性價格的原因:Thesticky-pricemodel一個企業(yè)的產(chǎn)品或服務的合意價格是這里，

a>0.假設兩類企業(yè):價格是伸縮性的企業(yè)，確定價格如上式。價格是黏性的企業(yè)，根據(jù)其預期的經(jīng)濟狀況事先宣布價格:CHAPTER15GovernmentDebtThesticky-pricemodel一個企業(yè)的產(chǎn)品或Thesticky-pricemodel假設企業(yè)預期產(chǎn)出等于其自然率水平，這樣為了推導出總供給曲線，我們首先要找到總價格水平的表達式.s

表示黏性價格企業(yè)的所占份額，這樣，我們能夠如下寫出總體價格水平。CHAPTER15GovernmentDebtThesticky-pricemodel假設企業(yè)預期產(chǎn)出Thesticky-pricemodel兩邊同時減去(1s

)P

:pricesetbyflexiblepricefirmspricesetbystickypricefirms兩邊同時除以s

:CHAPTER15GovernmentDebtThesticky-pricemodel兩邊同時減去(Thesticky-pricemodelPe越高

P越高如果企業(yè)預期高價格，這樣企業(yè)會提前確定高價格.其他企業(yè)的反映：也會制定高價格.高Y

高P

當收入高，對產(chǎn)品的需求增加，伸縮性價格的企業(yè)會制定高價格.伸縮性價格的企業(yè)所占份額越大，s越小，Y對P的影響越大。

CHAPTER15GovernmentDebtThesticky-pricemodelPe越高Thesticky-pricemodel最后,求解Y，推導出AS

方程:CHAPTER15GovernmentDebtThesticky-pricemodel最后,求解Y，推Thesticky-pricemodel與黏性工資模型相反，黏性價格模型意味著實際工資是親周期的:假設總產(chǎn)出／收入下降，這樣,企業(yè)發(fā)現(xiàn)其產(chǎn)品需求下降.黏性價格的企業(yè)減少生產(chǎn)，繼而減少其勞動需求.勞動需求向左邊移動，造成實際工資下降.CHAPTER15GovernmentDebtThesticky-pricemodel與黏性工資模型相總結(jié)與含義三個總供給模型中的每一個模型都包含SRAS曲線&方程總結(jié)的關(guān)系Y

PLRASSRASCHAPTER15GovernmentDebt總結(jié)與含義三個總供給模型中的每一個模型都包含SRAS曲線&方總結(jié)與含義假設積極的AD

沖擊，產(chǎn)出超過其自然率水平，P

超過人們的預期水平.Y

PLRASSRAS1SRAS2AD1AD2隨著時間推移,

Pe

提高,

SRAS

向上移動并且

產(chǎn)出回到自然率水平.CHAPTER15GovernmentDebt總結(jié)與含義假設積極的AD沖擊，產(chǎn)出超過其自然率水平，PInflation,Unemployment,andthePhillipsCurve菲利普斯曲線值得信賴嗎？UnemploymentRate(percent)123456789100246810InflationRate(percentperyear)1973196619721971196119621963196719681969197019651964CHAPTER15GovernmentDebtInflation,Unemployment,andt菲利普斯曲線值得信賴嗎？

123456789100246810UnemploymentRate(percent)InflationRate(percentperyear)1972197519811976197819791980197319741977CHAPTER15GovernmentDebt菲利普斯曲線值得信賴嗎？

12345678910024681菲利普斯曲線值得信賴嗎？

123456789100246810UnemploymentRate(percent)InflationRate(percentperyear)1980198119821984198619851979A1983B1987CCopyright?2004South-WesternCHAPTER15GovernmentDebt菲利普斯曲線值得信賴嗎？

12345678910024681Inflation,Unemployment,andthePhillipsCurveThePhillipscurve

表明：依賴于預期的通貨膨脹率,ecyclicalunemployment:實際失業(yè)率與自然失業(yè)率的背離供給沖擊,

這里，

>0是外生固定的.CHAPTER15GovernmentDebtInflation,Unemployment,andt從SRAS推導

thePhillipsCurveOkun’slawCHAPTER15GovernmentDebt從SRAS推導thePhillipsCurveOkunThePhillipsCurve和SRASSRAS

曲線:

產(chǎn)出與未預期到的價格變化有關(guān)系Phillipscurve:

失業(yè)率與未預期到的通貨膨脹率的變化有關(guān)系。CHAPTER15GovernmentDebtThePhillipsCurve和SRASSRASGraphingthePhillipscurve在短期,政策制定者們面臨trade-offbetween

andu.

u

短期的PhillipsCurveCHAPTER15GovernmentDebtGraphingthePhillipscurve在短期表明失業(yè)和通貨膨脹在短期中是此消彼漲的。.如果政策制定者擴大總需求，能夠降低失業(yè)，但是要以更高的通貨膨脹為代價。如果政策制定者緊縮總需求，能夠降低通貨膨脹，但是是以更高的暫時失業(yè)為代價。CHAPTER15GovernmentDebt表明失業(yè)和通貨膨脹在短期中是此消彼漲的。.CHAPTER1Expectationsand