曼昆《经济学原理》(宏观经济学分册)英文原版ppt课件——33aggregate_demand

12SHORTRUNECONOMICFLUCTUATIONSCOPYRIGHT2004SOUTHWESTERN33AGGREGATEDEMANDANDAGGREGATESUPPLYCOPYRIGHT2004SOUTHWESTERNSHORTRUNECONOMICFLUCTUATIONSECONOMICACTIVITYFLUCTUATESFROMYEARTOYEARINMOSTYEARSPRODUCTIONOFGOODSANDSERVICESRISESONAVERAGEOVERTHEPAST50YEARS,PRODUCTIONINTHEUSECONOMYHASGROWNBYABOUT3PERCENTPERYEARINSOMEYEARSNORMALGROWTHDOESNOTOCCUR,CAUSINGARECESSIONCOPYRIGHT2004SOUTHWESTERNSHORTRUNECONOMICFLUCTUATIONSARECESSIONISAPERIODOFDECLININGREALINCOMES,ANDRISINGUNEMPLOYMENTADEPRESSIONISASEVERERECESSIONCOPYRIGHT2004SOUTHWESTERNTHREEKEYFACTSABOUTECONOMICFLUCTUATIONSECONOMICFLUCTUATIONSAREIRREGULARANDUNPREDICTABLEFLUCTUATIONSINTHEECONOMYAREOFTENCALLEDTHEBUSINESSCYCLEMOSTMACROECONOMICVARIABLESFLUCTUATETOGETHERASOUTPUTFALLS,UNEMPLOYMENTRISESFIGURE1ALOOKATSHORTRUNECONOMICFLUCTUATIONSBILLIONSOF1996DOLLARSREALGDPAREALGDP10,0009,0008,0007,0006,0005,0004,0003,0002,00019651970197519801985199019952000COPYRIGHT2004SOUTHWESTERNCOPYRIGHT2004SOUTHWESTERNTHREEKEYFACTSABOUTECONOMICFLUCTUATIONSMOSTMACROECONOMICVARIABLESFLUCTUATETOGETHERMOSTMACROECONOMICVARIABLESTHATMEASURESOMETYPEOFINCOMEORPRODUCTIONFLUCTUATECLOSELYTOGETHERALTHOUGHMANYMACROECONOMICVARIABLESFLUCTUATETOGETHER,THEYFLUCTUATEBYDIFFERENTAMOUNTSFIGURE1ALOOKATSHORTRUNECONOMICFLUCTUATIONSBILLIONSOF1996DOLLARSBINVESTMENTSPENDING1,8001,6001,4001,2001,00080060040020019651970197519801985199019952000INVESTMENTSPENDINGCOPYRIGHT2004SOUTHWESTERNCOPYRIGHT2004SOUTHWESTERNTHREEKEYFACTSABOUTECONOMICFLUCTUATIONSASOUTPUTFALLS,UNEMPLOYMENTRISESCHANGESINREALGDPAREINVERSELYRELATEDTOCHANGESINTHEUNEMPLOYMENTRATEDURINGTIMESOFRECESSION,UNEMPLOYMENTRISESSUBSTANTIALLYFIGURE1ALOOKATSHORTRUNECONOMICFLUCTUATIONSPERCENTOFLABORFORCECUNEMPLOYMENTRATE02468101219651970197519801985199019952000UNEMPLOYMENTRATECOPYRIGHT2004SOUTHWESTERNCOPYRIGHT2004SOUTHWESTERNEXPLAININGSHORTRUNECONOMICFLUCTUATIONSHOWTHESHORTRUNDIFFERSFROMTHELONGRUNMOSTECONOMISTSBELIEVETHATCLASSICALTHEORYDESCRIBESTHEWORLDINTHELONGRUNBUTNOTINTHESHORTRUNCHANGESINTHEMONEYSUPPLYAFFECTNOMINALVARIABLESBUTNOTREALVARIABLESINTHELONGRUNTHEASSUMPTIONOFMONETARYNEUTRALITYISNOTAPPROPRIATEWHENSTUDYINGYEARTOYEARCHANGESINTHEECONOMYCOPYRIGHT2004SOUTHWESTERNTHEBASICMODELOFECONOMICFLUCTUATIONSTWOVARIABLESAREUSEDTODEVELOPAMODELTOANALYZETHESHORTRUNFLUCTUATIONSTHEECONOMYSOUTPUTOFGOODSANDSERVICESMEASUREDBYREALGDPTHEOVERALLPRICELEVELMEASUREDBYTHECPIORTHEGDPDEFLATORCOPYRIGHT2004SOUTHWESTERNTHEBASICMODELOFECONOMICFLUCTUATIONSTHEBASICMODELOFAGGREGATEDEMANDANDAGGREGATESUPPLYECONOMISTUSETHEMODELOFAGGREGATEDEMANDANDAGGREGATESUPPLYTOEXPLAINSHORTRUNFLUCTUATIONSINECONOMICACTIVITYAROUNDITSLONGRUNTRENDCOPYRIGHT2004SOUTHWESTERNTHEBASICMODELOFECONOMICFLUCTUATIONSTHEBASICMODELOFAGGREGATEDEMANDANDAGGREGATESUPPLYTHEAGGREGATEDEMANDCURVESHOWSTHEQUANTITYOFGOODSANDSERVICESTHATHOUSEHOLDS,FIRMS,ANDTHEGOVERNMENTWANTTOBUYATEACHPRICELEVELCOPYRIGHT2004SOUTHWESTERNTHEBASICMODELOFECONOMICFLUCTUATIONSTHEBASICMODELOFAGGREGATEDEMANDANDAGGREGATESUPPLYTHEAGGREGATESUPPLYCURVESHOWSTHEQUANTITYOFGOODSANDSERVICESTHATFIRMSCHOOSETOPRODUCEANDSELLATEACHPRICELEVELFIGURE2AGGREGATEDEMANDANDAGGREGATESUPPLYQUANTITYOFOUTPUTPRICELEVEL0AGGREGATESUPPLYAGGREGATEDEMANDEQUILIBRIUMOUTPUTEQUILIBRIUMPRICELEVELCOPYRIGHT2004SOUTHWESTERNCOPYRIGHT2004SOUTHWESTERNTHEAGGREGATEDEMANDCURVETHEFOURCOMPONENTSOFGDPYCONTRIBUTETOTHEAGGREGATEDEMANDFORGOODSANDSERVICESYCIGNXFIGURE3THEAGGREGATEDEMANDCURVEQUANTITYOFOUTPUTPRICELEVEL0AGGREGATEDEMANDPYY2P21ADECREASEINTHEPRICELEVEL2INCREASESTHEQUANTITYOFGOODSANDSERVICESDEMANDEDCOPYRIGHT2004SOUTHWESTERNCOPYRIGHT2004SOUTHWESTERNWHYTHEAGGREGATEDEMANDCURVEISDOWNWARDSLOPINGTHEPRICELEVELANDCONSUMPTIONTHEWEALTHEFFECTTHEPRICELEVELANDINVESTMENTTHEINTERESTRATEEFFECTTHEPRICELEVELANDNETEXPORTSTHEEXCHANGERATEEFFECTCOPYRIGHT2004SOUTHWESTERNWHYTHEAGGREGATEDEMANDCURVEISDOWNWARDSLOPINGTHEPRICELEVELANDCONSUMPTIONTHEWEALTHEFFECTADECREASEINTHEPRICELEVELMAKESCONSUMERSFEELMOREWEALTHY,WHICHINTURNENCOURAGESTHEMTOSPENDMORETHISINCREASEINCONSUMERSPENDINGMEANSLARGERQUANTITIESOFGOODSANDSERVICESDEMANDEDCOPYRIGHT2004SOUTHWESTERNWHYTHEAGGREGATEDEMANDCURVEISDOWNWARDSLOPINGTHEPRICELEVELANDINVESTMENTTHEINTERESTRATEEFFECTALOWERPRICELEVELREDUCESTHEINTERESTRATE,WHICHENCOURAGESGREATERSPENDINGONINVESTMENTGOODSTHISINCREASEININVESTMENTSPENDINGMEANSALARGERQUANTITYOFGOODSANDSERVICESDEMANDEDCOPYRIGHT2004SOUTHWESTERNWHYTHEAGGREGATEDEMANDCURVEISDOWNWARDSLOPINGTHEPRICELEVELANDNETEXPORTSTHEEXCHANGERATEEFFECTWHENAFALLINTHEUSPRICELEVELCAUSESUSINTERESTRATESTOFALL,THEREALEXCHANGERATEDEPRECIATES,WHICHSTIMULATESUSNETEXPORTSTHEINCREASEINNETEXPORTSPENDINGMEANSALARGERQUANTITYOFGOODSANDSERVICESDEMANDEDCOPYRIGHT2004SOUTHWESTERNWHYTHEAGGREGATEDEMANDCURVEMIGHTSHIFTTHEDOWNWARDSLOPEOFTHEAGGREGATEDEMANDCURVESHOWSTHATAFALLINTHEPRICELEVELRAISESTHEOVERALLQUANTITYOFGOODSANDSERVICESDEMANDEDMANYOTHERFACTORS,HOWEVER,AFFECTTHEQUANTITYOFGOODSANDSERVICESDEMANDEDATANYGIVENPRICELEVELWHENONEOFTHESEOTHERFACTORSCHANGES,THEAGGREGATEDEMANDCURVESHIFTSCOPYRIGHT2004SOUTHWESTERNWHYTHEAGGREGATEDEMANDCURVEMIGHTSHIFTSHIFTSARISINGFROMCONSUMPTIONINVESTMENTGOVERNMENTPURCHASESNET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