最新宏观经济学课件PPT课件.ppt 49页

'宏观经济学课件 TheClassicalLong-RunModelEconomistssometimesdisagreewitheachotherActuallymuchmoreagreementexistsamongeconomiststhanthereappearstobeOncedistinctionbetweenlong-runandshort-runbecomesclearManyapparentdisagreementsamongmacroeconomistsdissolveIfnotimehorizonisspecified,however,aneconomistislikelytofocusonhorizonheorshefeelsismostimportantSomethingaboutwhicheconomistssometimesdodisagree2 TheClassicalLong-RunModelIdeally,wewouldlikeoureconomytodowellinbothlong-runandshort-runUnfortunately,thereisoftenatrade-offbetweenthesetwogoalsDoingbetterinshort-runcanrequiresomesacrificeoflong-rungoals,andviceversaPolicesthatcanhelpussmoothouteconomicfluctuationsmayproveharmfultogrowthinthelong-runWhilepoliciesthatpromiseahighrateofgrowthmightrequireustoputupwithmoreseverefluctuationsinshort-run3 AssumptionsoftheClassicalModelMarket-clearingassumptionprovideshintaboutwhyclassicalmodeldoesabetterjoboverlongertimeperiods(severalyearsormore)thanshorteronesWe’lluseclassicalmodeltoansweravarietyofimportantquestionsabouteconomyinlong-run,suchasHowistotalemploymentdetermined?Howmuchoutputwillweproduce?Whatroledoestotalspendingplayintheeconomy?Whathappenswhenthingschange?7 HowMuchOutputWillWeProduce?Howcanwedisentanglewebofeconomicinteractionsweseearoundus?Decidewhichmarketormarketsbestsuittheproblembeinganalyzed,andIdentifybuyersandsellersIdentifytypeofenvironmentinwhichtheytradeButwhichmarketshouldwestartwith?LogicalstartismarketforresourcesLabor,landandnaturalresources,capitalandentrepreneurshipWe’llconcentrateourattentiononlaborOurquestionisHowmanyworkerswillbeemployedintheeconomy?8 Figure1:TheLaborMarket9 TheLaborMarketLaborsupplycurveslopesupwardBecause—aswagerateincreases—moreandmoreindividualsarebetteroffworkingthannotworkingThus,ariseinwagerateincreasesnumberofpeoplewhowanttowork—tosupplytheirlaborAswagerateincreaseseachfirmwillfindthat—tomaximizeprofit—itshouldemployfewerworkersthanbeforeWhenallfirmsbehavethiswaytogetherariseinwageratewilldecreasequantityoflabordemandedThisiswhyeconomy’slabordemandcurveslopesdownwardInclassicalview,economyachievesfullemploymentonitsown10 DeterminingtheEconomy’sOutputMosteffectivewaytomasteramacroeconomicmodelis“divideandconquer”Startwithpartofmodel,understanditwell,andthenaddinotherpartsAccordingly,ourclassicalanalysisofeconomyisdividedintotwoseparatequestionsWhatwouldbethelong-runequilibriumoftheeconomyiftherewereaconstantstateoftechnologyAndifquantitiesofallresourcesbesideslaborwerefixed?Whathappenstothislong-runequilibriumwhentechnologyandquantitiesofotherresourceschange?11 TheProductionFunctionRelationshipbetweentotalemploymentandtotalproductionintheeconomyGivenbyeconomy’saggregateproductionfunctionShowstotaloutputeconomycanproducewithdifferentquantitiesoflaborGivenconstantamountsofotherresourcesandcurrentstateoftechnologyInclassical,long-runvieweconomyreachesitspotentialoutputautomaticallyAnimportantconclusionofclassicalmodelandanimportantcharacteristicoftheeconomyinlong-runOutputtendstowarditspotential,full-employmentlevelonitsown,withnoneedforgovernmenttosteertheeconomytowardit12 Figure2:OutputDeterminationintheClassicalModel13 TheRoleofSpendingWhatifbusinessfirmsareunabletosellalloutputproducedbyafullyemployedlaborforce?EconomywouldnotbeabletosustainfullemploymentforverylongIfweareassertingthatpotentialoutputisanequilibriumfortheeconomyHadbetterbesurethattotalspendingonoutputisequaltototalproductionduringtheyearButcanwebesureofthis?Inclassicalviewanswerisyes14 TotalSpendinginaVerySimpleEconomyImagineaworldwithjusttwotypesofeconomicunitsHouseholdsandbusinessfirmsCircularFlowAdiagramthatshowshowgoods,resources,anddollarpaymentsflowbetweenhouseholdsandfirmsInasimpleeconomywithjusthouseholdsandfirmsinwhichhouseholdsspendalloftheirincomeTotalspendingmustbeequaltototaloutputKnownasSay’sLaw15 Figure3:TheCircularFlow16 TotalSpendinginaVerySimpleEconomySay’sLawnamedafterclassicaleconomistJeanBaptisteSay(1767-1832),whopopularizedtheideaInSay’sownwords“Aproductisnosoonercreatedthanit,fromthatinstant,affordsamarketforotherproductstothefullextentofitsownvalue…Thus,themerecircumstanceofthecreationofoneproductimmediatelyopensaventforotherproducts”Say’slawstatesthatbyproducinggoodsandservicesFirmscreateatotaldemandforgoodsandservicesequaltowhattheyhaveproducedorSupplycreatesitsowndemand17 TotalSpendinginaMoreRealisticEconomyDoesSay’slawalsoapplyinamorerealisticeconomy?IntherealworldHouseholdsdon’tspendalltheirincomeRather,someoftheirincomeissavedorgoestopaytaxesHouseholdsarenottheonlyspendersintheeconomyBusinessesandgovernmentbuysomeofthefinalgoodsandservicesweproduceInadditiontomarketsforgoodsandresources,thereisalsoaloanablefundsmarketWherehouseholdsavingismadeavailabletoborrowersinbusinessorgovernmentsectors18 SomeNewMacroeconomicVariablesPlannedinvestmentspending(IP)overaperiodoftimeistotalinvestmentspending(I)minuschangeininventoriesovertheperiodIP=I–ΔinventoriesNettaxes(T)aretotalgovernmenttaxrevenueminusgovernmenttransferpaymentsT=totaltaxrevenue–transfersHouseholdsaving(S)It’softenusefultoarriveathouseholdsavingintwostepsDeterminehowmuchincomehouseholdsectorhasleftafterpaymentofnettaxesHouseholdsector’sdisposableincomeDisposableIncome=TotalIncome–NetTaxesPartthatisnotspentisdefinedassaving(S)S=DisposableIncome–CTotalSpendinginClassicaInClassica,totalspendingissumofpurchasesmadebyhouseholdsector(C),businesssector(IP),andgovernmentsector(G)Totalspending=C+IP+G19 SomeNewMacroeconomicVariablesSavingandnettaxesarecalledleakagesoutofspendingAmountofincomethathouseholdsreceive,butdonotspendTherearealsoinjections—spendingfromsourcesotherthanhouseholdsAgovernment’spurchasesofgoodsandservicesPlannedinvestmentspending(IP)TotalspendingwillequaltotaloutputifandonlyiftotalleakagesintheeconomyareequaltototalinjectionsOnlyifsumofsavingandnettaxesisequaltosumofplannedinvestmentspendingandgovernmentpurchases20 Figure4:LeakagesandInjections21 TheLoanableFundsMarketWherehouseholdsmaketheirsavingavailabletothosewhoneedadditionalfundsTotalsupplyofloanablefundsisequaltohouseholdsavingFundssuppliedareloanedout,andhouseholdsreceiveinterestpaymentsonthesefundsBusinesses’demandforloanablefundsisequaltotheirplannedinvestmentspendingFundsobtainedareborrowed,andfirmspayinterestontheirloansBudgetdeficitExcessofgovernmentpurchasesovernettaxesBudgetofsurplusExcessofnettaxesovergovernmentpurchasesWhengovernmentpurchasesofgoodsandservices(G)aregreaterthannettaxes(T)GovernmentrunsabudgetdeficitequaltoG–TWhengovernmentpurchasesofgoodsandservices(G)arelessthannettaxes(T)GovernmentrunsabudgetsurplusequaltoT-G22 TheSupplyofFundsCurveSinceinterestisrewardforsavingandsupplyingfundstofinancialmarketRiseininterestrateincreasesquantityoffundssupplied(householdsaving),whileadropininterestratedecreasesitSupplyoffundscurveIndicateslevelofhouseholdsavingatvariousinterestratesQuantityoffundssuppliedtothefinancialmarketdependspositivelyoninterestrateThisiswhythesaving,orsupplyoffunds,curveslopesupwardOtherthingscanaffectsavingsbesidestheinterestrate,includingTaxratesExpectationsaboutthefutureGeneralwillingnessofhouseholdstopostponeconsumption23 Figure5:SupplyofHouseholdLoanableFunds24 TheDemandforFundsCurveWheninterestratefallsinvestmentspendingandthebusinessborrowingneededtofinanceitriseBusinessdemandforfundscurveslopesdownwardWhataboutgovernment’sdemandforfunds?Willit,too,beinfluencedbytheinterestrate?ProbablynotverymuchGovernmentseemstobecushionedfromcost-benefitconsiderationsthathauntbusinessdecisionsAnycompanypresidentwhoignoredinterestratesindecidinghowmuchtoborrowwouldbequicklyoutofajobU.S.presidentsandlegislatorshaveoftendonesowithlittlepoliticalcostGovernmentsector’sdeficitanditsdemandforfundsareindependentofinterestrateAsinterestratedecreasesquantityoffundsdemandedbybusinessfirmsincreasesWhilequantitydemandedbygovernmentremainsunchangedTherefore,totalquantityoffundsdemandedrises25 Figure6:BusinessDemandforLoanableFunds26 Figure7:TheDemandforFunds27 EquilibriumintheLoanableFundsMarketInclassicalviewloanablefundsmarketisassumedtoclearInterestratewillriseorfalluntilquantitiesoffundssuppliedanddemandedareequalCanwebesurethatalloutputproducedatfullemploymentwillbepurchased?28 Figure8:LoanableFundsMarketEquilibrium29 TheLoanableFundsMarketandSay’sLawAslongasloanablefundsmarketclears,Say’slawholdsTotalspendingequalstotaloutputThisistrueeveninamorerealisticeconomywithsaving,taxes,investmentandgovernmentdeficitHere’sanotherwaytoseethesameresult,intermsofasimpleequationLoanablefundsmarketclearsS=IP+(G–T)RearrangingthisequationbymovingTtoleftsideLoanablefundsmarketclearsS+T=IP+GSay’slawshowsthattotalvalueofspendingineconomywillequaltotalvalueofoutputRulesoutageneraloverproductionorunderproductionofgoodsintheeconomyItdoesnotpromiseusthateachfirmwillbeabletosellalloftheparticulargooditproduces30 Figure9:AnExpandedCircularFlow31 TheClassicalModel:ASummaryBeganwithacriticalassumptionAllmarketsclearInclassicalmodel,governmentneedn’tworryaboutemploymentEconomywillachievefullemploymentonitsownInclassicalmodel,governmentneedn’tworryabouttotalspendingEconomywillgeneratejustenoughspendingonitsowntobuyoutputthatafullyemployedlaborforceproduces32 UsingtheTheory:FiscalPolicyintheClassicalModelCouldgovernmentincreaseeconomy’stotalemploymentandtotaloutputbyraisingtotalspending?TwoideasforincreasingspendingcometomindGovernmentcouldsimplypurchasemoreoutputitselfMoregoods,liketanksandpolicecars,ormoreservices,likethoseprovidedbyhighschoolteachersandjudgesGovernmentcouldcutnettaxes,lettinghouseholdskeepmoreoftheirincomeSotheywouldspendmoreonfood,clothing,furniture,newcars,andsoonFiscalpolicyisachangeingovernmentpurchasesorinnettaxesDesignedtochangetotalspendingintheeconomyandtherebyinfluencelevelsofemploymentandoutputIdeabehindfiscalpolicysoundssensibleenoughButdoesitwork?Notifeconomybehavesaccordingtoclassicalmodel33 UsingtheTheory:FiscalPolicyWithABudgetDeficitWhatwouldhappenifthegovernmentofClassica—whichisrunningadeficit—attemptedtoincreaseemploymentandoutputbyincreasinggovernmentpurchasesCrowdingoutisadeclineinonesector’sspendingcausedbyanincreaseinsomeothersector’sspendingInclassicalmodelariseingovernmentpurchasescompletelycrowdsoutprivatesectorspendingsototalspendingremainsunchangedInclassicalmodel,anincreaseingovernmentpurchaseshasnoimpactontotalspendingandnoimpactontotaloutputortotalemploymentOppositesequenceofeventswouldhappenifgovernmentpurchasesdecreasedTotalspendingandtotaloutputwouldremainunchanged34 Figure10:CrowdingOutWithAnInitialBudgetDeficit35 FiscalPolicyWithABudgetSurplusTotalspendingremainsunchanged,andfiscalpolicyiscompletelyineffectiveSameconclusionwereachedaboutfiscalpolicywithagovernmentbudgetdeficitOurexplorationoffiscalpolicyshowsusthat,inlong-runGovernmenteffortstochangetotaloutputbychanginggovernmentspendingortaxesareunnecessaryandineffective36 Figure11:CrowdingOutWithAnInitialBudgetSurplus37 一、文学(文体)常识墨子(约前476年－前390年)，名翟，是春秋战国时期墨家学派的创始人。战国初期思想家、政治家、教育家、先秦诸子散文代表作家。墨家的基本思想主要有以下十点：兼爱、非攻、尚贤、尚同、天志、明鬼、非命、非乐、节用、节葬。 三、文言句式1．倒装句(1)宋何罪之有？(宾语前置，应为“宋有何罪”)(2)荆国有余于地，而不足于民。(介宾结构后置，应为“荆国于地有余，而于民不足”)(3)胡不见我于王？(介宾结构后置，应为“胡不于王见我”)2．省略句(1)将以(之)攻宋。(省略了介词的宾语“之”)(2)(子)胡不见我于王？(省略主语“子”) 3．判断句(1)臣以王吏之攻宋也，为与此同类。(“为”表判断)(2)宋所谓无雉兔鲋鱼者也。(者也，句末语气词，表判断)4．固定句式此犹锦绣之与短褐也。(犹……之与……也：好像……同……相比) 四、人物形象1．墨子：(1)墨子听说公输盘为楚国造云梯要攻打宋国，不远千里，走了十天十夜到楚国的国都来说服公输盘，表现墨子不畏艰辛，反对不正义的战争的“非攻”思想及爱好和平的思想。(2)墨子折服公输盘和楚王的巧妙、锋利的言辞，表现墨子是个出色的思想家和政治活动家，具有机灵、雄辩的口才。(3)墨子冒着生命危险只身深入敌国，说服公输盘和楚王。表现墨子为了阻止一场不正义的战争，不怕牺牲的勇敢精神。(4)墨子九距公输盘攻城之机变，说明墨子有勇有谋。2．公输盘：顽固、阴险，狡诈。3．楚王：霸道强硬、狡诈虚伪、贪婪好利。'