學(xué)習(xí)壓縮包經(jīng)濟學(xué)原理chapter

1133總需求與總供給AggregateDemandandAggregateSupply22短期經(jīng)濟波動

Short-RunEconomicFluctuations經(jīng)濟活動年復(fù)一年地波動Economicactivityfluctuatesfromyeartoyear.在大多數(shù)年份里，物品與服務(wù)的生產(chǎn)是上升的Inmostyearsproductionofgoodsandservicesrises.在過去50年，平均來說，美國經(jīng)濟的生產(chǎn)每年增長約3個百分點。Onaverageoverthepast50years,productionintheU.S.economyhasgrownbyabout3percentperyear.在一些年份，正常的增長沒能出現(xiàn)，導(dǎo)致了衰退。Insomeyearsnormalgrowthdoesnotoccur,causingarecession.

33短期經(jīng)濟波動

Short-RunEconomicFluctuations衰退是實際GDP下降、收入減少、失業(yè)上升的時期ArecessionisaperiodofdecliningrealGDP,fallinges,andrisingunemployment.蕭條是嚴重的衰退Adepressionisasevererecession.44關(guān)于經(jīng)濟波動的三個關(guān)鍵事實

ThreeKeyFactsAboutEconomicFluctuations經(jīng)濟波動是不規(guī)則和不可預(yù)測的。Economicfluctuationsareirregularandunpredictable.經(jīng)濟當(dāng)中的波動常常被稱作經(jīng)濟周期（或譯商業(yè)周期）Fluctuationsintheeconomyareoftencalledthe

businesscycle.大多數(shù)宏觀經(jīng)濟變量一起波動。Mostmacroeconomicvariablesfluctuatetogether.隨著產(chǎn)出下降，失業(yè)率上升。Asoutputfalls,unemploymentrises.55RealGDP

實際GDP短期經(jīng)濟波動一瞥ALookAtShort-RunEconomicFluctuations66短期經(jīng)濟波動一瞥：中國ALookAtShort-RunEconomicFluctuations:China資料來源：《中國國內(nèi)生產(chǎn)總值核算歷史資料，1952－1995》，《中國統(tǒng)計年鑒》以及作者計算。(a)實際GDP(1952=100)77關(guān)于經(jīng)濟波動的三個關(guān)鍵事實ThreeKeyFactsAboutEconomicFluctuations大多數(shù)宏觀經(jīng)濟變量一起波動。Mostmacroeconomicvariablesfluctuatetogether.大多數(shù)衡量某種收入或生產(chǎn)的宏觀經(jīng)濟變量幾乎同時波動。Mostmacroeconomicvariablesthatmeasuresometypeofeorproductionfluctuatecloselytogether.雖然許多宏觀經(jīng)濟變量一起波動，他們波動的幅度并不同。Althoughmanymacroeconomicvariablesfluctuatetogether,theyfluctuatebydifferentamounts.88短期經(jīng)濟波動一瞥ALookAtShort-RunEconomicFluctuations(b)InvestmentSpending投資支出99短期經(jīng)濟波動一瞥：中國ALookAtShort-RunEconomicFluctuations:China(b)投資支出(1952=100)1010短期經(jīng)濟波動一瞥：中國ALookAtShort-RunEconomicFluctuations:China實際GDP與投資支出(增長率%)投資實際GDP1111關(guān)于經(jīng)濟波動的三個關(guān)鍵事實ThreeKeyFactsAboutEconomicFluctuations隨著產(chǎn)出下降，失業(yè)上升。Asoutputfalls,unemploymentrises.實際GDP的變化和失業(yè)率的變化呈反向關(guān)系。ChangesinrealGDPareinverselyrelatedtochangesintheunemploymentrate.在衰退時期，失業(yè)大幅上升。Duringtimesofrecession,unemploymentrisessubstantially.1212短期經(jīng)濟波動一瞥ALookAtShort-RunEconomicFluctuations(c)UnemploymentRate失業(yè)率1313解釋短期經(jīng)濟波動

ExplainingShort-runEconomicFluctuations古典經(jīng)濟學(xué)的基本假設(shè)是古典二分法與貨幣中性。Thebasicassumptionsofclassicaleconomicsaretheclassicaldichotomyandmonetaryneutrality.按照古典經(jīng)濟學(xué)，我們在不引入名義變量（貨幣供給、價格水平）的情況下，就能夠考察實際變量（實際GDP、實際利率和失業(yè)）的決定。Accordingtoclassicaleconomics,weareabletoexaminethedeterminantsofrealvariables(realGDP,therealinterestrate,andunemployment)withoutintroducingnominalvariables(themoneysupplyandthepricelevel.)大多數(shù)經(jīng)濟學(xué)家相信，古典理論描述了長期中的世界，但沒有描述短期中的世界。Mosteconomistsbelievethatclassicaltheorydescribestheworldinthelongrunbutnotintheshortrun.1414解釋短期經(jīng)濟波動

ExplainingShort-runEconomicFluctuations短期內(nèi)，實際和名義變量高度相關(guān)。Intheshortrun,realandnominalvariablesarehighlyintertwined.貨幣供給的變化能夠暫時地將實際GDP移到其長期趨勢之外。ChangesinthemoneysupplycantemporarilypushrealGDPawayfromitslong-runtrend.總需求與總供給模型

TheModelofAggregateDemandandAggregateSupply經(jīng)濟學(xué)家使用總需求與總供給模型來解釋經(jīng)濟活動圍繞其長期趨勢的短期波動Economistusethemodelofaggregatedemandandaggregatesupplytoexplainshort-runfluctuationsineconomicactivityarounditslong-runtrend.1616總需求與總供給模型

TheModelofAggregateDemandandAggregateSupply短期經(jīng)濟波動模型集中關(guān)注兩個變量的行為。Themodelofshort-runeconomicfluctuationfocusesonthebehavioroftwovariables.（以實際GDP衡量的）經(jīng)濟中物品與服務(wù)的產(chǎn)出。Theeconomy’soutputofgoodsandservicesmeasuredbyrealGDP.（以CPI或GDP平減指數(shù)衡量的）整體價格水平。TheoverallpricelevelmeasuredbytheCPIortheGDPdeflator.1717總需求與總供給……

AggregateDemandandAggregateSupply...EquilibriumOutput均衡產(chǎn)出QuantityofOutput產(chǎn)出數(shù)量PriceLevel價格水平0Equilibriumpricelevel均衡價格水平AggregateSupply總供給AggregateDemand總需求1818總需求曲線

TheAggregateDemandCurve總需求曲線表示家庭、企業(yè)或政府在任一價格水平上想要購買的物品與服務(wù)的數(shù)量。Theaggregatedemandcurve

showsthequantityofgoodsandservicesthathouseholds,firms,andthegovernmentwanttobuyateachpricelevel.1919總需求曲線

TheAggregateDemandCurve其他條件不變，經(jīng)濟中整體價格水平的下降增加了物品與服務(wù)的需求數(shù)量。Otherthingsequal,andecreaseintheeconomy’soveralllevelofpricesraisesthequantityofgoodsandservicesdemanded.價格水平的上升減少物品與服務(wù)的需求數(shù)量。Anincreaseinthepricelevelreducesthequantityofgoodsandservicesdemanded.2020總需求曲線

TheAggregate-DemandCurve...QuantityofOutputPriceLevel0AggregateDemand總需求P1Y1Y2P22.…增加了物品與服務(wù)的需求數(shù)量increasesthequantityofgoodsandservicesdemanded.1.價格水平的下降A(chǔ)decreaseinthepricelevel...2121總需求曲線為什么向下傾斜

WhytheAggregateDemandCurveIsDownwardSloping總需求曲線向下傾斜的原因與單個市場需求曲線向下傾斜的原因有所不同。Thereasonforthedownwardslopingaggregatedemandcurveisnotthesameasforthedownwardslopingdemandcurveinanysinglemarket.在單一市場上，某一商品價格上升，消費者傾向于用另一更為廉價商品替代，引起該商品需求量下降。Inasinglemarket,whenthepriceforagoodincreases,consumerstendtosubstituteforacheapergood,thusthequantitydemandedforthatgooddecreases.這一替代效應(yīng)在所有價格都上升時不存在。Thissubstitutioneffectdoesnotexistwhenallthepricesincrease.2222總需求曲線為什么向下傾斜

WhytheAggregateDemandCurveIsDownwardSloping回顧：GDP（總支出）的四個組成部分（消費、投資、政府支出、凈出口）構(gòu)成了對物品與服務(wù)的總需求。Recall:ThefourcomponentsofGDP(totalexpenditure)contributetotheaggregatedemandforgoodsandservices.AD≡C+I+G+NX2323總需求曲線為什么向下傾斜

WhytheAggregateDemandCurveIsDownwardSloping價格水平與消費：財富效應(yīng)ThePriceLevelandConsumption:TheWealthEffect價格水平與投資：利率效應(yīng)ThePriceLevelandInvestment:TheInterestRateEffect價格水平與凈出口：匯率效應(yīng)ThePriceLevelandNetExports:TheExchange-RateEffect2424價格水平與消費：財富效應(yīng)

ThePriceLevelandConsumption:TheWealthEffect價格水平的下降提高了貨幣的真實價值，使得消費者更加富有，鼓勵他們支出更多。Adecreaseinthepricelevelraisestherealvalueofmoneyandmakesconsumerswealthier,whichinturnencouragesthemtospendmore.消費支出的上升意味著對物品與服務(wù)更大的需求數(shù)量。Thisincreaseinconsumerspendingmeanslargerquantitiesofgoodsandservicesdemanded.2525價格水平與投資：利率效應(yīng)

ThePriceLevelandInvestment:TheInterestRateEffect低物價減少了人們持有的現(xiàn)金人們選擇更多的儲蓄降低了利率，這鼓勵了對投資品的更大支出投資支出的增加意味著物品與服務(wù)的需求數(shù)量更大。2626價格水平與凈出口：匯率效應(yīng)

ThePriceLevelandnetExports:TheExchange-RateEffect美國的價格水平下降導(dǎo)致了美國的利率下降投資者轉(zhuǎn)向外國的投資,美元供給增加美元貶值外國物品變貴,本國物品變便宜進口下降,出口增加凈出口支出增加2727總需求曲線為什么會移動

WhytheAggregateDemandCurveMightShift總需求曲線向下傾斜，表示價格水平的下降增加了物品與服務(wù)總的需求數(shù)量。Thedownwardslopeoftheaggregatedemandcurveshowsthatafallinthepricelevelraisestheoverallquantityofgoodsandservicesdemanded.然而，在給定價格水平上，許多其他因素影響物品與服務(wù)的需求數(shù)量。Manyotherfactors,however,affectthequantityofgoodsandservicesdemandedatanygivenpricelevel.當(dāng)這些其他因素中的任一種發(fā)生改變，總需求曲線移動。Whenoneoftheseotherfactorschanges,theaggregatedemandcurveshifts.2828總需求曲線為什么會移動

WhytheAggregateDemandCurveMightShift來自消費的移動ShiftsarisingfromConsumption股市漲跌Stockmarketboom/crash關(guān)于消費與儲蓄權(quán)衡的偏好改變Preferenceschanges:consumption/savingtradeoff增稅減稅Taxhikes/cuts來自投資的移動ShiftsarisingfromInvestment更好的技術(shù)Bettertechnology樂觀或悲觀的預(yù)期Expectations,optimism/pessimism貨幣政策Monetarypolicy投資稅收減免InvestmentTaxCredit2929總需求曲線為什么會移動

WhytheAggregateDemandCurveMightShift來自政府購買的移動ShiftsarisingfromGovernmentPurchases增加聯(lián)邦國防開支Increaseonfederaldefensespending州或地方政府新修公路或?qū)W校State&localspendingonnewroads,schools來自凈出口的移動ShiftsarisingfromNetExports歐洲經(jīng)濟繁榮或衰退Booms/recessionsinEurope由于外匯市場上國際投機行為帶來的貨幣升值或貶值A(chǔ)ppreciation/depreciationresultingfrominternationalspeculationinforeignexchangemarket3030總需求曲線的移動

ShiftsintheAggregateDemandCurve...QuantityofOutputPriceLevel0Aggregatedemand,D1P1Y1D2Y23131總供給曲線

TheAggregateSupplyCurve總供給曲線表示企業(yè)在任一價格水平上生產(chǎn)和銷售的物品與服務(wù)的數(shù)量。Theaggregatesupplycurveshowsthequantityofgoodsandservicesthatfirmsproduceandsellateachpricelevel.3232總供給曲線

TheAggregateSupplyCurve經(jīng)濟中整體價格水平的上升傾向于增加物品與服務(wù)的供給數(shù)量。Anincreaseintheoveralllevelofpricesintheeconomytendstoraisethequantityofgoodsandservicessupplied.價格水平的下降傾向于減少物品與服務(wù)的供給數(shù)量。Adecreaseinthelevelofpricestendstoreducethequantityofgoodsandservicessupplied.3333總供給曲線……

TheAggregateSupplyCurve...QuantityofOutputPriceLevel0aggregatesupply總供給Y1P1Y22.減少了物品與服務(wù)的供給數(shù)量

reducesthequantityofgoodsandservicessupplied.P21.價格水平的下降A(chǔ)decreaseinthepricelevel3434總供給曲線為什么向上傾斜

WhytheAggregate

SupplyCurveSlopesUpward在一個理想的狀態(tài)下，當(dāng)價格水平變化時，企業(yè)面對的所有價格以同等比例變動，企業(yè)不會改變其產(chǎn)出。Inanidealstate,whenthepricelevelchanges,allthepricesfirmsface,includingpricesofoutputsandinputs,changeinthesameproportion,thusnofirmswillchangetheirproductionatall.3535總供給曲線為什么向上傾斜

WhytheAggregate

SupplyCurveSlopesUpward粘性工資理論TheSticky-WageTheory錯覺理論TheMisperceptionsTheory粘性價格理論TheSticky-PriceTheory3636粘性工資理論

TheSticky-WageTheory名義工資的調(diào)整是緩慢的，或者說，在短期內(nèi)是“粘性的”——工資并不隨著價格水平的下降而立即調(diào)整。Nominalwagesareslowtoadjust,orare“sticky”intheshortrun:Wagesdonotadjustimmediatelytoafallinthepricelevel.更低的價格水平使得雇傭和生產(chǎn)的利潤更低。Alowerpricelevelmakesemploymentandproductionlessprofitable.這就導(dǎo)致企業(yè)減少物品與服務(wù)的供給數(shù)量。Thisinducesfirmstoreducethequantityofgoodsandservicessupplied.3737錯覺理論

TheMisperceptionsTheory總體價格水平的下降，暫時地誤導(dǎo)供給者，使他們認為是他們產(chǎn)品的價格下降了。Afallintheoverallpriceleveltemporarilymisleadsuppliers;theybelieveit’sthepricesoftheirproductsthatfell.也就是說，他們錯誤地認為相對價格下降了。Thatis,theymistakenlybelievethattheirrelativepriceshavefallen.這種錯覺使得供給者減少物品與服務(wù)的供給數(shù)量。Thesemisperceptionsinducesupplierstodecreasethequantityofgoodsandservicessupplied.3838粘性價格理論

TheSticky-PriceTheory某些物品與服務(wù)的價格為適應(yīng)經(jīng)濟狀況變化所進行的調(diào)整是遲緩的。Pricesofsomegoodsandservicesadjustsluggishlyinresponsetochangingeconomicconditions:價格水平的未預(yù)料到的下降，留下某些企業(yè)的價格高于合意的水平。Anunexpectedfallinthepricelevelleavessomefirmswithhigher-than-desiredprices.這會壓低銷售，引起企業(yè)減少物品與服務(wù)的生產(chǎn)數(shù)量。Thisdepressessales,whichinducesfirmstoreducethequantityofgoodsandservicestheyproduce.3939總供給曲線為什么向上傾斜

WhytheAggregate

SupplyCurveSlopesUpward所有三個理論都可以用下述一個理論概括：Allthethreetheoriescanbesummarizedintoonetheorybelow:當(dāng)實際價格水平背離人們預(yù)期的價格水平時，產(chǎn)量就背離其自然率。Outputdeviatesfromitsnaturalratewhenthepriceleveldeviatesfromthepricelevelthatpeopleexpect.當(dāng)實際價格水平高于人們預(yù)期的水平（越多）時，產(chǎn)量就高于其自然率（越多）。Whenthepricerises(more)abovethelevelthatpeopleexpected,outputrises(more)aboveitsnaturalrate.4040總供給曲線為什么向上傾斜

WhytheAggregate

SupplyCurveSlopesUpward用數(shù)學(xué)公式將產(chǎn)品供給量、實際和預(yù)期價格水平的關(guān)系表述如下:Wecanexpresstheaggregatesupplycurvemathematicallyasfollows：產(chǎn)品供給量＝自然產(chǎn)量率＋a×(實際價格水平－預(yù)期價格水平)Y=Yn+a(P-Pe)a>0反映產(chǎn)出對價格的未預(yù)期改變的反應(yīng)程度。Whereaisanumberthatdetermineshowmuchoutputrespondstounexpectedchangesinthepricelevel.4141總供給曲線為什么向上傾斜

WhytheAggregate

SupplyCurveSlopesUpward預(yù)期價格水平（Pe）衡量人們對價格水平的預(yù)期值。Expectedpricelevel(Pe)measureshowmuchpeopleexpecttheoverallpricelevelwillbe.自然產(chǎn)量率是當(dāng)實際價格水平等于預(yù)期價格水平時的產(chǎn)量。Naturalrateofoutputistheoutputproducedwhenthepricelevelequalstotheexpectedpricelevel.4242總供給曲線為什么向上傾斜

WhytheAggregateSupplyCurveSlopesUpward預(yù)期價格（Pe）不變……當(dāng)實際價格（P）上升……結(jié)果是產(chǎn)出（Y）增加粘性工資理論供給者難以調(diào)整名義工資…………供給者的產(chǎn)品價格上升供給者由于實際工資下降而增加產(chǎn)出錯覺理論供給者認為其他產(chǎn)品價格不變…………供給者自己的產(chǎn)品價格上升供給者誤認為自己產(chǎn)品的相對價格上升，從而增加產(chǎn)出粘性價格理論供給者自己產(chǎn)品的價格難以調(diào)整…………其他供給者的價格上升供給者自己產(chǎn)品的相對價格下降，需求上升，從而增加產(chǎn)出。4343總供給曲線為什么會移動

WhytheAggregateSupplyCurveMightShift來自預(yù)期價格水平的移動ShiftsarisingfromtheExpectedPriceLevel來自自然產(chǎn)量率的變動Shiftsarisingfromthenaturallevelofoutput4444預(yù)期價格水平的上升減少了物品與服務(wù)的供給數(shù)量，將總供給曲線向左移動。Anincreaseintheexpectedpricelevelreducesthequantityofgoodsandservicessuppliedandshiftstheaggregatesupplycurvetotheleft.預(yù)期價格水平的下降增加了物品與服務(wù)的供給數(shù)量，將總供給曲線向右移動。Adecreaseintheexpectedpricelevelraisesthequantityofgoodsandservicessuppliedandshiftstheaggregatesupplycurvetotheright.總供給曲線為什么會移動：預(yù)期價格水平的影響

WhytheAggregateSupplyCurveMightShift:InfluenceofExpectedPriceLevel4545總供給曲線為什么會移動：預(yù)期價格水平的影響

WhytheAggregateSupplyCurveMightShift:InfluenceofExpectedPriceLevelQuantityofOutputPriceLevel0aggregatesupply總供給Y=YnP=PeP’=Pe’預(yù)期價格水平上升……Pe4646總供給曲線：短期與長期

TheAggregateSupplyCurve:Short-runvs.Long-run預(yù)期對總供給曲線位置的影響在解釋經(jīng)濟如何從短期轉(zhuǎn)向長期時起了關(guān)鍵作用。Theinfluenceofexpectationsonthepositionoftheaggregate-supplycurveplaysakeyroleinexplaininghowtheeconomymakesthetransitionfromtheshortruntothelongrun.4747總供給曲線：短期與長期

TheAggregateSupplyCurve:Short-runvs.Long-run短期中，預(yù)期價格水平不變，實際價格水平的上升增加了產(chǎn)品供給量，得到一條向上傾斜的總供給曲線。Intheshortrun,expectedpricelevelisfixed,anincreaseinactualpricelevelwillincreasethequantityofoutputsupplied,leadingtoanupwardaggregatesupplycurve.長期中，預(yù)期價格水平與實際價格水平相等，得到一條垂直于自然產(chǎn)量率處的總供給曲線。Inthelongrun,expectedpricelevelisequaltoactualpricelevel,leadingtoanverticalaggregatesupplycurveatthenaturalrateofoutput.4848總供給曲線：短期與長期

TheAggregateSupplyCurve:Short-runvs.Long-run短期總供給曲線向上傾斜。Intheshortrun,theaggregate-supplycurveisupwardsloping.長期總供給曲線是垂直的。Inthelongrun,theaggregate-supplycurveisvertical.4949長期總供給曲線

TheLong-RunAggregateSupplyCurve垂直的長期總供給曲線是古典理論的圖形表示。Theverticallong-runaggregate-supplycurveisagraphicalrepresentationoftheclassicaltheory.在長期中，經(jīng)濟的物品與服務(wù)的生產(chǎn)依賴于它的勞動、資本與自然資源的供給，以及將這些生產(chǎn)要素轉(zhuǎn)化為產(chǎn)品與服務(wù)的可行技術(shù)。Inthelong-run,aneconomy’sproductionofgoodsandservicesdependsonitssuppliesoflabor,capital,andnaturalresourcesandontheavailabletechnologyusedtoturnthesefactorsofproductionintogoodsandservices.價格水平在長期中不影響這些變量。Thepriceleveldoesnotaffectthesevariablesinthelongrun.5050長期總供給曲線

TheLong-RunAggregate-SupplyCurve...QuantityofOutputNaturalrateofoutput自然產(chǎn)量率PriceLevel0Long-runaggregatesupply長期總供給P1P22.…不影響長期中物品與服務(wù)的供給數(shù)量doesnotaffectthequantityofgoodsandservicessuppliedinthelongrun.1.價格水平的改變Achangeinthepricelevel…5151長期總供給曲線

TheLong-RunAggregateSupplyCurve長期總供給曲線垂直于自然產(chǎn)量率處。Thelong-runaggregatesupplycurveisverticalatthenaturalrateofoutput.這一生產(chǎn)水平也被稱為潛在產(chǎn)出或充分就業(yè)產(chǎn)出。Thislevelofproductionisalsoreferredtoas

potentialoutputor

full-employmentoutput.5252總供給曲線為什么會移動：自然產(chǎn)量率的變動

WhytheAggregateSupplyCurveMightShift:TheChangeofNaturalRateofOutput任何改變自然產(chǎn)量率的經(jīng)濟變化都會同樣地移動短期和長期的總供給曲線。Anychangeintheeconomythataltersthenaturalrateofoutputshiftstheaggregate-supplycurve,bothlong-runandshort-run.這樣的移動可以按照古典模型中影響產(chǎn)出的若干因素來分類。Theshiftsmaybecategorizedaccordingtothevariousfactorsintheclassicalmodelthataffectoutput.5353總供給曲線為什么會移動：自然產(chǎn)量率的變動

WhytheAggregateSupplyCurveMightShift:TheChangeofNaturalRateofOutput來自勞動的移動ShiftsarisingfromLabor來自資本的移動ShiftsarisingfromCapital來自自然資源的移動ShiftsarisingfromNaturalResources來自技術(shù)知識的移動ShiftsarisingfromTechnologicalKnowledge5454總供給曲線為什么會移動：自然產(chǎn)量率的變動

WhytheAggregateSupplyCurveMightShift:TheChangeofNaturalRateofOutputQuantityofOutputNaturalrateofoutput自然產(chǎn)量率PriceLevel0Long-runaggregatesupply長期總供給Short-runaggregatesupply短期總供給自然產(chǎn)量率增加ExpectedpriceLevel預(yù)期價格水平Y(jié)n55551.在長期中，技術(shù)進步移動長期總供給Inthelong-run,technologicalprogressshiftslong-runaggregatesupply...LRAS2000LRAS1990QuantityofOutputPriceLevel0P1980Y1980AD1980P2000P1990LRAS19802.…貨幣供給的增長移動總需求andgrowthinthemoneysupplyshiftsaggregate-demand...AD2000AD19904.…和持續(xù)的通貨膨脹andongoinginflation.Y1990Y20003.…導(dǎo)致產(chǎn)出增長leadingtogrowthinoutput...運用總供求模型描述長期增長與通貨膨脹……UsingAggregateDemandandAggregateSupplytoDepictLong-RunGrowthandInflation...5656長期均衡

TheLong-RunEquilibriumQuantityofOutput產(chǎn)量PriceLevel價格水平0Short-runaggregatesupply短期總供給總需求AggregatedemandALong-runaggregatesupply長期總供給Equilibrium

price=Expectedprice均衡價格=預(yù)期價格Naturalrateofoutput自然產(chǎn)量率5757長期均衡

TheLong-RunEquilibrium當(dāng)經(jīng)濟達到長期均衡時，預(yù)期價格水平調(diào)整到與實際價格水平相等。Whentheeconomyreachesthislong-runequilibrium,theexpectedpricelevelwillhaveadjustedtoequaltheactualpricelevel.產(chǎn)出等于自然產(chǎn)量率。Theoutputequalstoitsnaturalrate.經(jīng)濟的長期均衡處于總需求曲線、短期和長期總供給曲線的交點處。Thelong-runequilibriumoftheeconomyisfoundwheretheaggregate-demandcurvecrossestheshort-runandlong-runaggregate-supplycurve.5858經(jīng)濟波動的兩大原因

TwoCausesofEconomicFluctuations分析經(jīng)濟波動的四個步驟：Fourstepsintheprocessofanalyzingeconomicfluctuations:決定事件是影響總供給還是總需求Determinewhethertheeventaffectsaggregatesupplyoraggregatedemand.決定曲線移動的方向Decidewhichdirectionthecurveshifts.使用圖形比較短期內(nèi)的新舊均衡Usethediagramtocomparetheinitialandthenewequilibriumintheshortrun找出經(jīng)濟從短期均衡到長期均衡的轉(zhuǎn)移路徑Keeptrackofthetransitionbetweentheshortandlongrunequilibrium.5959經(jīng)濟波動的兩大原因

TwoCausesofEconomicFluctuations總需求移動Shiftsinaggregatedemand總供給移動Shiftsinaggregatesupply601.總需求減少Adecreaseinaggregatedemand…AD2總需求的收縮……

AContractioninAggregateDemand...QuantityofOutputPriceLevel0Short-runaggregatesupply,AS1

Long-runaggregatesupplyAggregatedemand,AD1AP1Y1BP2Y22.…導(dǎo)致產(chǎn)出在短期內(nèi)下降causesoutputtofallintheshortrun…AS2CP33.…但是隨著時間推移，短期總供給曲線移動butovertime,theshort-runaggregate-supplycurveshifts…4.…產(chǎn)出回到其自然率上andoutputreturnstoitsnaturalrate.6161總需求移動

ShiftsinAggregateDemand在短期內(nèi)，總需求的移動導(dǎo)致經(jīng)濟中物品與服務(wù)的產(chǎn)出發(fā)生波動。Intheshortrun,shiftsinaggregatedemandcausefluctuationsintheeconomy’soutputofgoodsandservices.在長期中，總需求的移動影響整體的價格水平但不影響產(chǎn)出。Inthelongrun,shiftsinaggregatedemandaffecttheoverallpricelevelbutdonotaffectoutput.通過影響總需求，政策制定者有可能能夠緩解經(jīng)濟波動的嚴重影響。Policymakerswhoinfluenceaggregatedemandcanpotentiallymitigatetheseverityofeconomicfluctuations.6262總供給的不利移動

AnAdverseShiftinAggregateSupply除預(yù)期外的決定總供給的因素的不利變動將短期和長期曲線都向左移動。Anadversechangeinoneofthedeterminantsofaggregatesupplyexceptforexpectationshiftsboththeshort-runandlong-runcurvestotheleft:自然產(chǎn)量率下降。Thenaturalrateofoutputfall.6363Long-runaggregatesupplyShort-runaggregatesupply,AS1QuantityofOutputPriceLevel0AggregatedemandAY1P1總供給的不利移動……

An

AdverseShiftinAggregateSupply...3.…和價格水平上升andthepriceleveltorise.

P22.…導(dǎo)致產(chǎn)出下降causesoutputtofall…BY2AS34.…長期內(nèi)價格水平繼續(xù)上升inthelongrun,pricelevelrisesmore.

P3C1.總供給曲線的不利移動。Anadverseshiftintheaggregate-supplycurve…AS2Y35.…產(chǎn)出進一步下降andoutputfallsmore.6464滯脹

Stagflation總供給的不利移動導(dǎo)致滯脹——衰退和通貨膨脹并存。Adverseshiftsinaggregatesupplycausestagflation—acombinationofrecessionandinflation.產(chǎn)出下降，失業(yè)增加，價格上升。Outputfalls,unemploymentrises,andpricesrise.政策制定者能夠影響總需求，但不能同時抵消這兩種不利的影響。Policymakerswhocaninfluenceaggregatedemandcannotoffsetbothoftheseadverseeffectssimultaneously.6565對于衰退的政策反應(yīng)

PolicyResponsestoRecession政策制定者對衰退的反應(yīng)可以是以下方式之一Policymakersmayrespondtoarecessioninoneofthefollowingways:什么也不做，等待價格和工資的調(diào)整。Donothingandwaitforpricesandwagestoadjust.采取行動，通過貨幣與財政政策來增加總需求。Takeactiontoincreaseaggregatedemandbyusingmonetaryandfiscalpolicy.6666對于衰退的政策反應(yīng)

PolicyResponsestoRecession對即使是短期的經(jīng)濟衰退做出適當(dāng)?shù)恼叻磻?yīng)，來源于凱恩斯的主張。Thelongrunisamisleadingguidetocurrentaffairs.Inthelongrunwearealldead.Economistssetthemselvestooeasy,toouselessa