1、C H A P T E R 2007 Worth Publishers,all rights reservedGovernment Debt15slide 1CHAPTER 15 Government DebtIn this chapter,you will learn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。CountryGov Debt(%of GDP)CountryGov Debt(%of GDP)Japan159U.S.A.64Italy125Sweden62Greece108F
2、inland53Belgium99Norway52France77Denmark50Portugal77Spain49Germany70U.K.47Austria69Ireland30Canada69Korea20Netherlands64Australia15slide 3CHAPTER 15 Government DebtRatio of U.S.govt debt to GDP00.20.40.60.811.21791 1815 1839 1863 1887 1911 1935 1959 1983 2007Revolutionary WarCivil WarWW1WW2Iraq Wars
3、lide 4CHAPTER 15 Government DebtThe U.S.experience in recent years1980s早期到 1990s早期debt-GDP ratio:25.5%in 1980,48.9%in 1993due to Reagan tax cuts,increases in defense spending&entitlements1990s早期 到2000年$290b deficit in 1992,$236b surplus in 2000debt-GDP ratio fell to 32.5%in 2000due to rapid growth,s
4、tock market boom,tax hikes从2001以来the return of huge deficits,due to Bush tax cuts,2001 recession,Iraq warslide 5CHAPTER 15 Government DebtThe troubling fiscal outlookThe U.S.population is aging.Health care costs are rising.Spending on entitlements like Social Security and Medicare is growing.Deficit
5、s and the debt are projected to significantly increaseslide 6CHAPTER 15 Government DebtPercent of U.S.population age 65+Percent of pop.58111417202319501960197019801990200020102020203020402050actualprojectedslide 7CHAPTER 15 Government DebtU.S.government spending on Medicare and Social SecurityPercen
6、t of GDP02468195019551960196519701975198019851990199520002005slide 8CHAPTER 15 Government DebtCBO projected U.S.federal govt debt in two scenariosPercent of GDP0501001502002503002005201020152020202520302035204020452050optimistic scenariopessimistic scenarioslide 9CHAPTER 15 Government DebtProblems m
7、easuring the deficit1.Inflation2.Capital assets3.Uncounted liabilities4.The business cycleslide 10CHAPTER 15 Government DebtMEASUREMENT PROBLEM 1:Inflation假设实际债务保持不变，这意味着a zero real deficit.在该情况下the nominal debt D 以通货膨胀率的速度增长:D/D =or D =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。slide 11C
8、HAPTER 15 Government DebtMEASUREMENT PROBLEM 1: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:In 1979,nominal deficit=$28 billioninflation=8.6%debt=$495 billion D =0.086$495b =$43breal deficit=$28b$43b=$15b surplusslide 12CHAPTER 15 Government DebtMEASUREMENT PROBLEM 2:Capital AssetsCurrently,defici
9、t=change in debtBetter,capital budgeting:deficit=(change in debt)(change in assets)EX:Suppose govt sells an office building and uses the proceeds to pay down the debt.under current system,deficit would fallunder capital budgeting,deficit unchanged,because fall in debt is offset by a fall in assets.P
10、roblem w/cap budgeting:Determining which govt expenditures count as capital expenditures.slide 13CHAPTER 15 Government DebtMEASUREMENT PROBLEM 3:Uncounted liabilitiesCurrent measure of deficit omits important liabilities of the government:future pension payments owed to current govt workers.future S
11、ocial Security paymentscontingent liabilities,e.g.,covering federally insured deposits when banks fail(Hard to attach a dollar value to contingent liabilities,due to inherent uncertainty.)slide 14CHAPTER 15 Government DebtMEASUREMENT PROBLEM 4:The business cycleThe deficit varies over the business c
12、ycle due to automatic stabilizers(unemployment insurance,the income tax system).These are not measurement errors,but do make it harder to judge fiscal policy stance.E.g.,is an observed increase in deficit due to a downturn or an expansionary shift in fiscal policy?slide 15CHAPTER 15 Government DebtM
13、EASUREMENT PROBLEM 4:The business cycleSolution:cyclically adjusted budget deficit(aka“full-employment deficit”)based on estimates of what govt spending&revenues would be if economy were at the natural rates of output&unemployment.slide 16CHAPTER 15 Government DebtThe cyclical contribution to the U.
14、S.Federal budget-120-80-40040801201965 1970 1975 1980 1985 1990 1995 2000 2005billions of current dollarsslide 17CHAPTER 15 Government DebtThe bottom lineslide 18CHAPTER 15 Government DebtIs the govt debt really a problem?考虑减税，减税导致政府债务相应地增加。Two viewpoints:1.Traditional view2.Ricardian viewslide 19CH
15、APTER 15 Government DebtThe traditional viewShort run:Y,uLong run:Y 和 u 回到自然失业率水平closed economy:r,Iopen economy:,NX(or higher trade deficit)Very long run: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。slide 20CHAPTER 15 Government DebtThe Ricardian viewdue to David Ricardo(1820),more recently advanced by Robert Barr
16、oAccording to Ricardian equivalence,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slide 21CHAPTER 15 Government DebtThe logic of Ricardian Equivalence消费者是forward-looking,知道现在的a debt-financed tax cut today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tax liability.
17、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。slide 22CHAPTER 15 Government DebtProblems with Ricardian EquivalenceMyopia: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as a windfall.Borrowing constraints: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 a tax cut.Future generations: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。slide 23CHAPTER 15 Government
18、 DebtEvidence against Ricardian Equivalence?Early 1980s:Reagan tax cuts 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Income tax withholding reduced，刺激了经济Almost half of consumers increased consumption.This delayed taxes but didnt make consumers better off.slide 24CHAPTER 15 Government DebtEvidence
19、against Ricardian Equivalence?Proponents of R.E.argue that the Reagan tax cuts did not provide a fair test of R.E.Consumers may have expected the debt to be repaid with future spending cuts instead of future tax hikes.Private saving may have fallen for reasons other than the tax cut,such as optimism
20、 about the economy.Because the data is subject to different interpretations,both views of govt debt survive.slide 25CHAPTER 15 Government DebtOTHER PERSPECTIVES:Balanced budgets vs.optimal fiscal policySome politicians have proposed amending the U.S.Constitution to require balanced federal govt budg
21、et every year.Many economists reject this proposal,arguing that deficit should be used tostabilize output&employmentsmooth taxes in the face of fluctuating incomeredistribute income across generations when appropriateslide 26CHAPTER 15 Government DebtOTHER PERSPECTIVES:Fiscal effects on monetary pol
22、icyGovt deficits may be financed by printing moneyA high govt debt may be an incentive for policymakers to create inflation(to reduce real value of debt at expense of bond holders)Fortunately:little evidence that the link between fiscal and monetary policy is important most governments know the foll
23、y of creating inflation most central banks have(at least some)political independence from fiscal policymakersslide 27CHAPTER 15 Government DebtOTHER PERSPECTIVES:Debt and politics“Fiscal policy is not made by angels”Greg Mankiw,p.449Some do not trust policymakers with deficit spending.They argue tha
24、tpolicymakers do not worry about true costs of their spending,since burden falls on future taxpayerssince future taxpayers cannot participate in the decision process,their interests may not be taken into accountThis is another reason for the proposals for a balanced budget amendment(discussed above)
25、.slide 28CHAPTER 15 Government DebtOTHER PERSPECTIVES:International dimensionsGovt budget deficits can lead to trade deficits,which must be financed by borrowing from abroad.Large govt debt may increase the risk of capital flight,as foreign investors may perceive a greater risk of default.Large debt
26、 may reduce a countrys political clout in international affairs.slide 29CHAPTER 15 Government DebtCASE STUDY:Inflation-indexed Treasury bondsStarting in 1997,the U.S.Treasury issued bonds with returns indexed to the CPI.Benefits:Removes inflation risk,the risk that inflation and hence real interest
27、rate will turn out different than expected.May encourage private sector to issue inflation-adjusted bonds.Provides a way to infer the expected rate of inflationslide 30CHAPTER 15 Government DebtCASE STUDY:Inflation-indexed Treasury bonds01234562003-01-032003-06-272003-12-192004-06-112004-12-032005-0
28、5-272005-11-182006-05-12percent(annual rate)rate on non-indexed bondimplied expected inflation raterate on indexed bond1.Relative to GDP,the U.S.governments debt is moderate compared to other countries2.Standard figures on the deficit are imperfect measures of fiscal policy because theyare not corre
29、cted for inflationdo not account for changes in govt assetsomit some liabilities(e.g.,future pension payments to current workers)do not account for effects of business cyclesCHAPTER 15 Government Debtslide 313.In the traditional view,a debt-financed tax cut increases consumption and reduces national
30、 saving.In a closed economy,this leads to higher interest rates,lower investment,and a lower long-run standard of living.In an open economy,it causes an exchange rate appreciation,a fall in net exports(or increase in the trade deficit).4.The Ricardian view holds that debt-financed tax cuts do not af
31、fect consumption or national saving,and therefore do not affect interest rates,investment,or net exports.CHAPTER 15 Government Debtslide 325.Most economists oppose a strict balanced budget rule,as it would hinder the use of fiscal policy to stabilize output,smooth taxes,or redistribute the tax burde
32、n across generations.6.Government debt can have other effects:may lead to inflationpoliticians can shift burden of taxes from current to future generationsmay reduce countrys political clout in international affairs or scare foreign investors into pulling their capital out of the countryCHAPTER 15 G
33、overnment Debtslide 33C H A P T E R 2007 Worth Publishers,all rights reservedCHAPTER 13 Aggregate Supplyslide 35CHAPTER 15 Government Debt相同的政策在不同时期的不同结果：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44，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
34、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。slide 36CHAPTER 15 Government Debt学习目的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the Phillips 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slide 37CHAPTER 15 Government Debt三种总供给模型三种总供给模型1.黏性工资模型2.不完全信
35、息模型3.黏性价格模型以上所有的三个模型表明短期供给曲线为:()eYYPP natural rate of outputa positive parameterthe expected price levelthe actual price levelagg.outputslide 38CHAPTER 15 Government DebtThe sticky-wage model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:eWPeWPPPTarget real wageslide 39CHAPTER 15 Go
36、vernment Debt黏性工资模型黏性工资模型如果现实情况如下eWPPPePPePPePP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()eYYPP slide 40CHAPTER 15 Government Debt假定：就业量由企业对劳动力需求决定。slide 41CHAPTER 15 Government Debt黏性工资模型黏性工资模型 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
37、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。slide 42CHAPTER 15 Government Debt实际工资的实际工资的 周期性表现周期性表现Percentage change in realwagePercentage change in real GDP1982197519931992196019961999199719981979197019801991197419901984200019721965-3-2-10123786544 3 2 1 0-1-2-3-4-5slide 43CHAPTER 15 Government De
38、btThe imperfect-information model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slide 44CHAPTER 15 Government DebtThe imperfect-information model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the expected price level,P e.假设 P 提高，但是 P e 没有（未预期到）这样供给者会认为其产品相对价格
39、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P e，Y 将上升。()eYYPP slide 45CHAPTER 15 Government DebtThe sticky-price model 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.as in monopolistic competition)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。slide 46CHAPTER 15 Gover
40、nment DebtThe sticky-price model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:()pPYYa()eeepPYYaslide 47CHAPTER 15 Government DebtThe sticky-price model假设假设企业预期产出等于其自然率水平，这样()eeepPYYaepP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。slide 48CHAPTER 15 Govern
41、ment DebtThe sticky-price model两边同时减去(1s)P :(1)()ePs PsPYYaprice set by flexible price firmsprice set by sticky price firms(1)()esPs PsYYa两边同时除以 s:(1)()esPPYYsaslide 49CHAPTER 15 Government DebtThe sticky-price modelP e 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
42、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。(1)()esPPYYsaslide 50CHAPTER 15 Government DebtThe sticky-price model最后,求解Y，推导出 AS 方程:(1)()esPPYYsa(),eYYPP 这里 (1)ss aslide 51CHAPTER 15 Government DebtThe sticky-price model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.
43、slide 52CHAPTER 15 Government Debt总结与含义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 PLRASYSRAS()eYYPP ePPePPePPslide 53CHAPTER 15 Government Debt总结与含义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 PLRASSRAS1 equation:()eYYPP SRAS11ePPSRAS2AD1AD22eP2P33ePP随着时间推移,P e 提高,SRAS 向上移动并且 产出回到自然率水平.1YY2Y3Yslide 54CHAPTER
44、 15 Government DebtInflation,Unemployment,and the Phillips Curve菲利普斯曲线值得信赖吗？菲利普斯曲线值得信赖吗？UnemploymentRate(percent)123456789100246810Inflation Rate(percent per year)1973196619721971196119621963196719681969197019651964slide 55CHAPTER 15 Government Debt菲利普斯曲线值得信赖吗？菲利普斯曲线值得信赖吗？123456789100246810Unemploym
45、entRate(percent)Inflation Rate(percent per year)1972197519811976197819791980197319741977slide 56CHAPTER 15 Government Debt菲利普斯曲线值得信赖吗？菲利普斯曲线值得信赖吗？123456789100246810UnemploymentRate(percent)Inflation Rate(percent per year)1980198119821984198619851979A1983B1987CCopyright 2004 South-Westernslide 57CHAP
46、TER 15 Government DebtInflation,Unemployment,and the Phillips CurveThe Phillips curve 表明：依赖于预期的通货膨胀率,ecyclical unemployment:实际失业率与自然失业率的背离供给冲击,()enuu这里，0是 外生固定的.slide 58CHAPTER 15 Government Debt从从SRAS推导推导 the Phillips Curve(1)()eYYPP(2)(1)()ePPYY 11(4)()()(1)()ePPPPYY (5)(1)()eYY (6)(1)()()nYYuu(7)
47、()enuu(3)(1)()ePPYYOkuns lawslide 59CHAPTER 15 Government DebtThe Phillips Curve 和和 SRASSRAS 曲线:产出与未预期到的价格变化有关系Phillips curve:失业率与未预期到的通货膨胀率的变化有关系。SRAS:()eYYPP Phillips curve:()enuuslide 60CHAPTER 15 Government DebtGraphing the Phillips curve在短期,政策制定者们面临 trade-off between and u.u nu1 短期的 Phillips Cu
48、rvee()enuu slide 61CHAPTER 15 Government Debt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。slide 62CHAPTER 15 Government DebtExpectations and the Short-Run Phillips Curveadaptive expectations:rational expectations:slide 63CHAPTER 15 Government DebtAdapt
49、ive expectationsAdaptive expectations:人们根据最近观察到的通货膨胀来形成他们的通货膨胀预期.一个简单例子:预期通货膨胀率=去年实际的通货膨胀率1()nuu1e这样,the P.C.变为slide 64CHAPTER 15 Government DebtInflation inertia在这种形式中，the Phillips 曲线意味着通货膨胀有惯性惯性:在缺少供给冲击或者周期性失业的时候，通货膨胀会以目前的速度继续发生。过去的通货膨胀会影响目前对通货膨胀的预期，这又会影响人们制定的工资&价格。1()nuuslide 65CHAPTER 15 Governm
50、ent Debt提高提高&降低通货膨胀的两种原因降低通货膨胀的两种原因需求拉动的通货膨胀需求拉动的通货膨胀:需求冲击引起通货膨胀。正面的总需求冲击，导致失业低于自然失业率水平，从而”拉动”通货膨胀上升；反之，则相反。成本推动的通货膨胀成本推动的通货膨胀：供给冲击引起通货膨胀。负面的供给冲击会提高生产成本，使得企业提高价格。“推动”通货膨胀上升；反之，则相反。1()nuuslide 66CHAPTER 15 Government DebtShifting the Phillips curve-expectation人们可以随着时间调整预期，通货膨胀和失业的取舍关系只在短期中成立.u nu1e()
