曼昆 宏观经济学1

蔡伟毅厦门大学金融系Email:wycai@Phonehapter1TheScienceofMacroeconomicsWhatmacroeconomistsstudyHoweconomiststhinkHowthisbookproceedsImportantissuesinmacroeconomicsWhydoesthecostoflivingkeeprising?Whyaremillionsofpeopleunemployed,evenwhentheeconomyisbooming?Whyarethererecessions?

Canthegovernmentdoanythingtocombatrecessions?Shouldit??ImportantissuesinmacroeconomicsWhatisthegovernmentbudgetdeficit?Howdoesitaffecttheeconomy?WhydoestheU.S.havesuchahugetradedeficit?Whyaresomanycountriespoor?

Whatpoliciesmighthelpthemgrowoutofpoverty?1-1WhatMacroeconomistsStudyShort-RunInflationanddeflationUnemploymentLong-RunEconomicgrowthMacroeconomics,thestudyoftheeconomyasawhole,attemptstoanswertheseandmanyrelatedquestions1-2HowEconomistsThinkTheoryasmodelbuilding(endogenousvariablesandexogenousvariables)Prices:flexibleversusstickyMicroeconomicthinkandmacroeconomicmodelsTounderstandtheeconomy,economistsusemodels—theoriesthatsimplifyrealityinordertorevealhowexogenousvariablesinfluenceendogenousvariables.Economicmodels…aresimplifiedversionsofamorecomplexrealityirrelevantdetailsarestrippedawayUsedtoshowtherelationshipsbetweeneconomicvariablesexplaintheeconomy’sbehaviordevisepoliciestoimproveeconomicperformanceEndogenousandExogenousVariablesEndogenousvariablesarethosevariablesthatamodeltriestoexplain.Exogenousvariablesarethosevariablesthatamodeltakesasgiven.Thepurposeofamodelistoshowhowtheexogenousvariablesaffecttheendogenousvariables.AMultitudeofModelsNoonemodelcanaddressalltheissueswecareabout.Forexample,Ifwewanttoknowhowafallinaggregateincomeaffectsnewcarprices,wecanusetheS/Dmodelfornewcars.Butifwewanttoknowwhyaggregateincomefalls,weneedadifferentmodel.AMultitudeofModelsSowewilllearndifferentmodelsforstudyingdifferentissues(e.g.unemployment,inflation,long-rungrowth).Foreachnewmodel,youshouldkeeptrackofitsassumptions,whichofitsvariablesareendogenousandwhichareexogenous,thequestionsitcanhelpusunderstand,andthoseitcannot.Prices:FlexibleVersusStickyMarketclearing:anassumptionthatpricesareflexibleandadjusttoequatesupplyanddemandimmediately.Intheshortrun,manypricesaresticky---theyadjustonlysluggishlyinresponsetosupply/demandimbalances.

Forexample,laborcontractsthatfixthenominalwageforayearorlongermagazinepricesthatpublisherschangeonlyonceevery3-4yearsPrices:FlexibleVersusStickyTheeconomy’sbehaviordependspartlyonwhetherpricesarestickyorflexible:Ifpricesaresticky,thendemandwon’talwaysequatesupply.Thishelpsexplainunemployment(excesssupplyoflabor)theoccasionalinabilityoffirmstosellwhattheyproduceLongrun:pricesflexible,marketsclear,economybehavesverydifferently.Outlineofthisbook:Introductorymaterial(chaps.1&2)ClassicalTheory

(chaps.3-6)

Howtheeconomyworksinthelongrun,whenpricesareflexibleGrowthTheory

(chaps.7-8)

ThestandardoflivinganditsgrowthrateovertheverylongrunBusinessCycleTheory

(chaps9-13)

Howtheeconomyworksintheshortrun,whenpricesaresticky.Outlineofthisbook:Policydebates

(Chaps.14-15)

Shouldthegovernmenttrytosmoothbusinesscyclefluctuations?Isthegovernment’sdebtaproblem?Microeconomicfoundations

(Chaps.16-19)

Insightsfromlookingatthebehaviorofconsumers,firms,andotherissuesfromamicroeconomicperspective.ChaptersummaryMacroeconomicsisthestudyoftheeconomyasawhole,includinggrowthinincomeschangesintheoveralllevelofpricestheunemploymentrateMacroeconomistsattempttoexplaintheeconomyandtodevisepoliciestoimproveitsperformance.ChaptersummaryEconomistsusedifferentmodelstoexaminedifferentissues.Modelswithflexiblepricesdescribetheeconomyi