曼昆 宏观经济学教案Ecn101_lecture25

1macroeconomicsfiftheditionN.GregoryMankiwPowerPoint®SlidesbyRonCronovichmacro©2003WorthPublishers,allrightsreservedCHAPTERFIFTEENGovernmentDebtCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide1InthischapteryouwilllearnaboutInthischapteryouwilllearnaboutƒthesizeoftheU.S.government’sdebt,andhowitcomparestothatofothercountriesƒproblemsmeasuringthebudgetdeficitƒthetraditionalandRicardianviewsofthegovernmentdebtƒotherperspectivesonthedebtCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide2IndebtednessoftheWorld’sGovernmentsIndebtednessoftheWorld’sGovernments5555PortugalPortugal2424NorwayNorway5858FranceFrance2626AustraliaAustralia6262U.S.A.U.S.A.2727NetherlandsNetherlands6464U.K.U.K.4040AustriaAustria6767DenmarkDenmark4646GermanyGermany100100GreeceGreece4949SwedenSweden101101CanadaCanada5151FinlandFinland105105BelgiumBelgium5353SpainSpain108108ItalyItaly5454IrelandIreland119119JapanJapanGovDebtGovDebt(%ofGDP)(%ofGDP)CountryCountryGovDebtGovDebt(%ofGDP)(%ofGDP)CountryCountryCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide3TheU.S.GovernmentDebtTheU.S.GovernmentDebt--GDPratioGDPratioRevolutionaryWarCivilWarWorldWarIWorldWarII1.210.80.60.40.201791181118311851187118911911193119511971199120012CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide4TheU.S.experienceinrecentyearsTheU.S.experienceinrecentyearsEarly1980sthroughearly1990sƒDebt-GDPratio:25.5%in1980,48.9%in1993ƒDuetoReagantaxcuts,increasesindefensespending&entitlementsEarly1990sthrough2000ƒ$290bdeficitin1992,$236bsurplusin2000ƒdebt-GDPratiofellto32.5%in2000ƒDuetorapidgrowth,stockmarketboom,taxhikes2001-2003ƒThereturnofhugedeficits,duetoBushtaxcutsandeconomicslowdownCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide5TheFiscalFutureTheFiscalFutureTheagingpopulation:•lowerbirthrates•increasedlifeexpectancy•retirementofBabyBoomers510152025197019902010203020502070%ofU.S.populationage65&upCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide6ƒThenumberofpeoplereceivingSocialSecurity,Medicareisgrowingfasterthanthenumberworking,payingtaxesƒCongressionalBudgetOfficeprojections:yeardebt-GDPratio203040%204093%2050206%TheFiscalFutureTheFiscalFutureCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide7ProblemsMeasuringtheDeficitProblemsMeasuringtheDeficit1.Inflation2.Capitalassets3.Uncountedliabilities4.Thebusinesscycle3CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide8Measurementproblem1:Measurementproblem1:InflationInflationƒToseewhyinflationisaproblem,supposetherealdebtisconstant,whichimpliesazerorealdeficit.ƒInthiscase,thenominaldebtDgrowsattherateofinflation:∆D/D=πor∆D=πDƒThereporteddeficit(nominal)isπDeventhoughtherealdeficitiszero.ƒHence,shouldsubtractπDfromthereporteddeficittocorrectforinflation.CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide9Measurementproblem1:Measurementproblem1:InflationInflationƒCorrectingthedeficitforinflationcanmakeahugedifference,especiallywheninflationishigh.ƒExample:In1979,nominaldeficit=$28billioninflation=8.6%debt=$495billionπD=0.086×$495b=$43brealdeficit=$28b−$43b=$15bsurplusCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide10Measurementproblem2:Measurementproblem2:CapitalAssetsCapitalAssetsƒCurrently:deficit=changeindebtƒBetter:Capitalbudgetingdeficit=(changeindebt)−(changeinassets)ƒEX:Supposegovtsellsanofficebuildingandusestheproceedstopaydownthedebt.–Undercurrentsystem,deficitwouldfall–Undercapitalbudgeting,deficitunchanged,becausefallindebtisoffsetbyafallinassetsƒProblemw/capbudgeting:determiningwhichgovtexpenditurescountascapitalexpenditures.CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide11Measurementproblem3:Measurementproblem3:UncountedliabilitiesUncountedliabilitiesCurrentmeasureofdeficitomitsimportantliabilitiesofthegovernment:ƒfuturepensionpaymentsowedtocurrentgovtworkersƒfutureSocialSecuritypaymentsƒcontingentliabilities(thoughhardtoattachadollarvaluewhentheoutcomeisuncertain)4CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide12Measurementproblem4:Measurementproblem4:ThebusinesscycleThebusinesscycleƒThedeficitvariesoverthebusinesscycleduetoautomaticstabilizers(unemploymentinsurance,theincometaxsystem).ƒThesearenotmeasurementerrors,butdomakeithardertojudgefiscalpolicystance.EX:Isanobservedincreaseindeficitduetoadownturnorexpansionaryshiftinfiscalpolicy?ƒSolution:cyclicallyadjustedbudgetdeficit(aka“full-employmentdeficit”)-basedonestimatesofwhatgovtspending&revenueswouldbeifeconomywereatthenaturalratesofoutput&unemployment.CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide13ThebottomlineThebottomlineWemustexercisecarewheninterpretingthereporteddeficitfigures.WemustexercisecareWemustexercisecarewheninterpretingwheninterpretingthereporteddeficitfigures.thereporteddeficitfigures.CHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide14IstheIsthegovtgovtdebtreallyaproblem?debtreallyaproblem?Twoviewpoints:1.Traditionalview2.RicardianviewCHAPTER15CHAPTER15GovernmentDebtGovernmentDebtslide15Thetraditionalviewofataxcut&Thetraditionalviewofataxcut&correspondingincreaseincorrespondingincreaseingovtgovtdebtdebtƒShortrun:↑Y,↓uƒL