CronovichChap01new宏观经济学课件

LearningobjectivesThischapterintroducesyouto(1)theissuesthatmacroeconomistsstudy;(2)thetoolsthatmacroeconomistsuse;(3)someimportantconceptsinmacroeconomicanalysis宏观经济学家研究的问题；使用的工具；宏观经济分析中的一些重要概念LearningobjectivesThischapte0ImportantissuesinmacroeconomicsWhyaremillionsofpeopleunemployed,evenwhentheeconomyisbooming?Whyarethererecessions?

Canthegovernmentdoanythingtocombatrecessions?Shouldit??为何即使经济高涨的时候，也有大量劳动力失业？为什么有衰退？政府能做什么？该不该做？Importantissuesinmacroecono1ImportantissuesinmacroeconomicsWhatisthegovernmentbudgetdeficit?Howdoesitaffecttheeconomy?WhydoestheU.S.havesuchahugetradedeficit?Whyaresomanycountriespoor?

Whatpoliciesmighthelpthemgrowoutofpoverty?什么是政府预算赤字（budgetdeficit）？美国为什么有巨额赤字？为什么那么多的国家贫穷？什么样的政策可以帮助他们摆脱贫困？Importantissuesinmacroecono2U.S.GrossDomesticProduct

inbillionsofchained1996dollarslong-runupwardtrend…GDPU.S.GrossDomesticProduct

i3U.S.GrossDomesticProduct

inbillionsofchained1996dollarsRecessionslongesteconomicexpansiononrecord最长的经济扩张记录衰退U.S.GrossDomesticProduct

i4Whylearnmacroeconomics?

为什么学习宏观经济学？Themacroeconomyaffectssociety’swell-being（社会福利）.example:Unemploymentandsocialproblems

Eachone-pointincreaseintheu-rate（失业率）isassociatedwith:920moresuicides（自杀者）650morehomicides（杀人者）4000morepeopleadmittedtostatementalinstitutions3300morepeoplesenttostateprisons（监狱）37,000moredeaths（死亡）increasesindomesticviolenceandhomelessness（无家）可归）例如：失业和社会问题Whylearnmacroeconomics?

为什么学5Whylearnmacroeconomics?Themacroeconomyaffectsyourwell-being.Unemploymentandearningsgrowth每小时工资增长率失业率Whylearnmacroeconomics?Them6Whylearnmacroeconomics?Themacroeconomyaffectsyourwell-being.InterestratesandmortgagepaymentsFora$150,00030-yearmortgage（抵押）:

$9,888$8245.21%$11,520$9606.63%6/21/02annualpaymentmonthlypaymentactualrateon30-yearmortgagedate6/20/03Whylearnmacroeconomics?Them7Whylearnmacroeconomics?Themacroeconomyaffectspolitics¤tevents.Inflationandunemploymentinelectionyearsyear Urate inflationrate elec.outcome1976 7.7% 5.8% Carter(D)1980 7.1% 13.5% Reagan(R)1984 7.5% 4.3% Reagan(R)1988 5.5% 4.1% BushI(R)1992 7.5% 3.0% Clinton(D)1996 5.4% 3.3% Clinton(D)2000 4.0% 3.4% BushII(R)Whylearnmacroeconomics?Them8Economicmodels（经济模型）…aresimplifiedversionsofamorecomplexrealityirrelevantdetailsarestrippedawayUsedto（1）showtherelationshipsbetweeneconomicvariables（2）explaintheeconomy’sbehavior（3）devisepoliciestoimproveeconomicperformance不相干的细节都被剥离掉了是对真实世界的简化Economicmodels（经济模型）…aresimp9Exampleofamodel:

Thesupply&demandfornewcarsexplainsthefactorsthatdeterminethepriceofcarsandthequantitysoldassumesthemarketiscompetitive:eachbuyerandselleristoosmalltoaffectthemarketpriceVariables:Q

d=quantityofcarsthatbuyersdemandQ

s=quantitythatproducerssupplyP=priceofnewcarsY=aggregateincome（外生变量）Ps=priceofsteel(aninput)（外生变量）Exampleofamodel:

Thesupp10Thedemandforcarsshowsthatthequantity

ofcarsconsumersdemand

isrelatedtothepriceofcars

andaggregateincome.Thedemandforcarsshowsthat11Digression:FunctionalnotationGeneralfunctionalnotation

showsonlythatthevariablesarerelated:Alistofthevariables

thataffectQ

dDigression:Functionalnotati12Digression:FunctionalnotationGeneralfunctionalnotation

showsonlythatthevariablesarerelated:Aspecificfunctionalformshows

theprecisequantitativerelationship:Digression:Functionalnotati13Themarketforcars:demandQQuantityofcarsP

Price

ofcarsDThedemandcurveshowstherelationshipbetweenquantitydemandedandprice,otherthingsequal.Themarketforcars:demandQ14Themarketforcars:supplyQQuantityofcarsP

Price

ofcarsDSThesupplycurveshowstherelationshipbetweenquantitysuppliedandprice,otherthingsequal.Themarketforcars:supplyQ15Themarketforcars:equilibriumQQuantityofcarsP

Price

ofcarsSDequilibriumpriceequilibrium

quantityThemarketforcars:equilibr16Theeffectsofanincreaseinincome:D2QQuantityofcarsP

Price

ofcarsSD1Q1P1Anincreaseinincomeincreasesthequantity

ofcarsconsumersdemandateachprice...…whichincreasestheequilibriumpriceandquantity.P2Q2Theeffectsofanincreasein17Theeffectsofasteelpriceincrease:QQuantityofcarsP

Price

ofcarsS1DQ1P1AnincreaseinPsreducesthequantityofcarsproducerssupplyateachprice……whichincreasesthemarketpriceandreducesthequantity.P2Q2S2Ps=priceofsteel(aninput)Theeffectsofasteelpricei18Endogenousvs.exogenousvariables:Thevaluesofendogenousvariables

aredeterminedinthemodel.Thevaluesofexogenousvariables

aredeterminedoutsidethemodel:

themodeltakestheirvalues&behavior

asgiven.Inthemodelofsupply&demandforcars,内生变量对外生变量外生的Y=aggregateincomePs=priceofsteel(aninput)Endogenousvs.exogenousvaria19Nowyoutry:Writedowndemandandsupply

equationsforwirelessphones;

includetwoexogenousvariables

ineachequation.Drawasupply-demandgraph

forwirelessphones.Useyourgraphtoshowhowachangeinoneofyourexogenousvariablesaffectsthemodel’sendogenousvariables.Nowyoutry:Writedowndemand20AmultitudeofmodelsNoonemodelcanaddressalltheissueswecareabout.Forexample,Ifwewanttoknowhow

afallinaggregateincomeaffectsnewcarprices,wecanusetheS/Dmodel（供需模型）fornewcars.Butifwewanttoknowwhyaggregateincomefalls,weneedadifferentmodel.没有一个模型是万能的，不同问题需要不同模型。AmultitudeofmodelsNoonemo21AMultitudeofModelsSowewilllearndifferentmodelsforstudyingdifferentissues(e.g.,unemployment,inflation,long-rungrowth).Foreachnewmodel,youshouldkeeptrackof

itsassumptions（它的假定）,whichofitsvariablesareendogenousandwhichareexogenous（变量内生还是外生）,thequestionsitcanhelpusunderstand,andthoseitcannot.AMultitudeofModelsSowewil22Prices:flexibleversusstickyMarketclearing（市场出清）:anassumptionthatpricesareflexibleandadjusttoequatesupplyanddemand.Intheshortrun,manypricesaresticky（粘性的）---

theyadjustonlysluggishly（行动迟缓地）inresponsetosupply/demandimbalances.

Forexample,laborcontractsthatfixthenominalwage

forayearorlongermagazinepricesthatpublisherschange

onlyonceevery3-4yearsPrices:flexibleversusstick23Prices:flexibleversusstickyTheeconomy’sbehaviordependspartlyonwhetherpricesarestickyorflexible:Ifpricesaresticky,thendemandwon’talwaysequalsupply.Thishelpsexplainunemployment(excesssupplyoflabor)theoccasionalinabilityoffirmstosellwhattheyproduce.Longrun:pricesflexible,marketsclear,economybehavesverydifferently

如果价格是粘性的，那么，需求不一定总是等于总供给。Prices:flexibleversusstick24Outlineofthisbook:Introductorymaterial(Chaps.1&2)ClassicalTheory

（古典理论）(Chaps.3to6)

Howtheeconomyworksinthelongrun,whenpricesareflexibleGrowthTheory

(Chaps.7to8)

（经济增长理论）

ThestandardoflivinganditsgrowthrateovertheverylongrunBusinessCycleTheory

（经济周期理论(Chaps9to13)

Howtheeconomyworksintheshortrun,whenpricesaresticky）Outlineofthisbook:Introduct25Outlineofthisbook:Policydebates

(Chaps.14to15)

Shouldthegovernmenttrytosmoothbusinesscyclefluctuations?Isthegovernment’sdebt(债务)aproblem?Microeconomicfoundations

(Chaps.16to19)

Insightsfromlookingatthebehaviorofconsumers,firms,andotherissuesfromamicroeconomicperspectiveOutlineofthisbook:Policyde26ChaptersummaryMacroeconomicsisthestudyoftheeconomyasawhole,includinggrowthinincomes,changesintheoveralllevelofprices,theunemploymentrate.Macroeconomistsattempttoexplaintheeconomyandtodevisepoliciestoimproveitsperformance.

1、宏观经济研究经济整体：包括收入增长、价格水平全面变化、失业率；2、解释经济并设计政策以改进绩效。ChaptersummaryMacroeconomics27ChaptersummaryEconomistsusedifferentmodelstoexaminedifferentissues.（使用数学模型来探讨不同问题）Modelswithflexibleprices（易变价格模型）describetheeconomyinthelongrun;modelswithstickyprices（粘性价格模型）describeeconomyintheshortrun.Macroeconomiceventsandperformancearisefrommanymicroeconomictransactions（微观经济交易）;somacroeconomicsusesmanyofthetoolsofmicroeconomics（微观经济工具）.

ChaptersummaryEconomistsuse28LearningobjectivesThischapterintroducesyouto(1)theissuesthatmacroeconomistsstudy;(2)thetoolsthatmacroeconomistsuse;(3)someimportantconceptsinmacroeconomicanalysis宏观经济学家研究的问题；使用的工具；宏观经济分析中的一些重要概念LearningobjectivesThischapte29ImportantissuesinmacroeconomicsWhyaremillionsofpeopleunemployed,evenwhentheeconomyisbooming?Whyarethererecessions?

Canthegovernmentdoanythingtocombatrecessions?Shouldit??为何即使经济高涨的时候，也有大量劳动力失业？为什么有衰退？政府能做什么？该不该做？Importantissuesinmacroecono30ImportantissuesinmacroeconomicsWhatisthegovernmentbudgetdeficit?Howdoesitaffecttheeconomy?WhydoestheU.S.havesuchahugetradedeficit?Whyaresomanycountriespoor?

Whatpoliciesmighthelpthemgrowoutofpoverty?什么是政府预算赤字（budgetdeficit）？美国为什么有巨额赤字？为什么那么多的国家贫穷？什么样的政策可以帮助他们摆脱贫困？Importantissuesinmacroecono31U.S.GrossDomesticProduct

inbillionsofchained1996dollarslong-runupwardtrend…GDPU.S.GrossDomesticProduct

i32U.S.GrossDomesticProduct

inbillionsofchained1996dollarsRecessionslongesteconomicexpansiononrecord最长的经济扩张记录衰退U.S.GrossDomesticProduct

i33Whylearnmacroeconomics?

为什么学习宏观经济学？Themacroeconomyaffectssociety’swell-being（社会福利）.example:Unemploymentandsocialproblems

Eachone-pointincreaseintheu-rate（失业率）isassociatedwith:920moresuicides（自杀者）650morehomicides（杀人者）4000morepeopleadmittedtostatementalinstitutions3300morepeoplesenttostateprisons（监狱）37,000moredeaths（死亡）increasesindomesticviolenceandhomelessness（无家）可归）例如：失业和社会问题Whylearnmacroeconomics?

为什么学34Whylearnmacroeconomics?Themacroeconomyaffectsyourwell-being.Unemploymentandearningsgrowth每小时工资增长率失业率Whylearnmacroeconomics?Them35Whylearnmacroeconomics?Themacroeconomyaffectsyourwell-being.InterestratesandmortgagepaymentsFora$150,00030-yearmortgage（抵押）:

$9,888$8245.21%$11,520$9606.63%6/21/02annualpaymentmonthlypaymentactualrateon30-yearmortgagedate6/20/03Whylearnmacroeconomics?Them36Whylearnmacroeconomics?Themacroeconomyaffectspolitics¤tevents.Inflationandunemploymentinelectionyearsyear Urate inflationrate elec.outcome1976 7.7% 5.8% Carter(D)1980 7.1% 13.5% Reagan(R)1984 7.5% 4.3% Reagan(R)1988 5.5% 4.1% BushI(R)1992 7.5% 3.0% Clinton(D)1996 5.4% 3.3% Clinton(D)2000 4.0% 3.4% BushII(R)Whylearnmacroeconomics?Them37Economicmodels（经济模型）…aresimplifiedversionsofamorecomplexrealityirrelevantdetailsarestrippedawayUsedto（1）showtherelationshipsbetweeneconomicvariables（2）explaintheeconomy’sbehavior（3）devisepoliciestoimproveeconomicperformance不相干的细节都被剥离掉了是对真实世界的简化Economicmodels（经济模型）…aresimp38Exampleofamodel:

Thesupply&demandfornewcarsexplainsthefactorsthatdeterminethepriceofcarsandthequantitysoldassumesthemarketiscompetitive:eachbuyerandselleristoosmalltoaffectthemarketpriceVariables:Q

d=quantityofcarsthatbuyersdemandQ

s=quantitythatproducerssupplyP=priceofnewcarsY=aggregateincome（外生变量）Ps=priceofsteel(aninput)（外生变量）Exampleofamodel:

Thesupp39Thedemandforcarsshowsthatthequantity

ofcarsconsumersdemand

isrelatedtothepriceofcars

andaggregateincome.Thedemandforcarsshowsthat40Digression:FunctionalnotationGeneralfunctionalnotation

showsonlythatthevariablesarerelated:Alistofthevariables

thataffectQ

dDigression:Functionalnotati41Digression:FunctionalnotationGeneralfunctionalnotation

showsonlythatthevariablesarerelated:Aspecificfunctionalformshows

theprecisequantitativerelationship:Digression:Functionalnotati42Themarketforcars:demandQQuantityofcarsP

Price

ofcarsDThedemandcurveshowstherelationshipbetweenquantitydemandedandprice,otherthingsequal.Themarketforcars:demandQ43Themarketforcars:supplyQQuantityofcarsP

Price

ofcarsDSThesupplycurveshowstherelationshipbetweenquantitysuppliedandprice,otherthingsequal.Themarketforcars:supplyQ44Themarketforcars:equilibriumQQuantityofcarsP

Price

ofcarsSDequilibriumpriceequilibrium

quantityThemarketforcars:equilibr45Theeffectsofanincreaseinincome:D2QQuantityofcarsP

Price

ofcarsSD1Q1P1Anincreaseinincomeincreasesthequantity

ofcarsconsumersdemandateachprice...…whichincreasestheequilibriumpriceandquantity.P2Q2Theeffectsofanincreasein46Theeffectsofasteelpriceincrease:QQuantityofcarsP

Price

ofcarsS1DQ1P1AnincreaseinPsreducesthequantityofcarsproducerssupplyateachprice……whichincreasesthemarketpriceandreducesthequantity.P2Q2S2Ps=priceofsteel(aninput)Theeffectsofasteelpricei47Endogenousvs.exogenousvariables:Thevaluesofendogenousvariables

aredeterminedinthemodel.Thevaluesofexogenousvariables

aredeterminedoutsidethemodel:

themodeltakestheirvalues&behavior

asgiven.Inthemodelofsupply&demandforcars,内生变量对外生变量外生的Y=aggregateincomePs=priceofsteel(aninput)Endogenousvs.exogenousvaria48Nowyoutry:Writedowndemandandsupply

equationsforwirelessphones;

includetwoexogenousvariables

ineachequation.Drawasupply-demandgraph

forwirelessphones.Useyourgraphtoshowhowachangeinoneofyourexogenousvariablesaffectsthemodel’sendogenousvariables.Nowyoutry:Writedowndemand49AmultitudeofmodelsNoonemodelcanaddressalltheissueswecareabout.Forexample,Ifwewanttoknowhow

afallinaggregateincomeaffectsnewcarprices,wecanusetheS/Dmodel（供需模型）fornewcars.Butifwewanttoknowwhyaggregateincomefalls,weneedadifferentmodel.没有一个模型是万能的，不同问题需要不同模型。AmultitudeofmodelsNoonemo50AMultitudeofModelsSowewilllearndifferentmodelsforstudyingdifferentissues(e.g.,unemployment,inflation,long-rungrowth).Foreachnewmodel,youshouldkeeptrackof

itsassumptions（它的假定）,whichofitsvariablesareendogenousandwhichareexogenous（变量内生还是外生）,thequestionsitcanhelpusunderstand,andthoseitcannot.AMultitudeofModelsSowewil51Prices:flexibleversusstickyMarketclearing（市场出清）:anassumptionthatpricesareflexibleandadjusttoequatesupplyanddemand.Intheshortrun,manypricesaresticky（粘性的）---

theyadjustonlysluggishly（行动迟缓地）inresponsetosupply/demandimbalances.

Forexample,laborcontractsthatfixthenominalwage

forayearorlongermagazinepricesthatpublisherschange

onlyonceevery3-4yearsPrices:flexibleversusstick52Prices:flexibleversusstickyTheeconomy’sbehaviordependspartlyonwhetherpricesarestickyorflexible:Ifpricesaresticky,thendemandwon’talwaysequalsupply.Thishelpsexplainunemployment(excesssupplyoflabor)theoccasi