經(jīng)濟(jì)學(xué)發(fā)展經(jīng)濟(jì)學(xué)

LeadingTheoriesofEconomicDevelopment:FiveApproachesClassicalScenario古典經(jīng)濟(jì)增長理論Linear-stages-of-growthmodel

線性增長模型Neoclassicalmodels

新古典增長模型Endogenousgrowth

內(nèi)生經(jīng)濟(jì)增長模型亞當(dāng)·斯密與報(bào)酬遞增產(chǎn)出、生活水平提高→資本積累→利潤的儲(chǔ)蓄→工業(yè)和農(nóng)業(yè)的專業(yè)化勞動(dòng)分工勞動(dòng)分工決定了勞動(dòng)生產(chǎn)率。勞動(dòng)分工提高勞動(dòng)生產(chǎn)率有三種途徑：

1、工人工作技能的提升，即邊干邊學(xué)。

2、分工的細(xì)化節(jié)省了在不同工作間轉(zhuǎn)移的時(shí)間。

3、機(jī)器的發(fā)明使同一個(gè)勞動(dòng)者可以從事多種工作。勞動(dòng)分工受到市場規(guī)模的限制。

1、如機(jī)器的使用只有在市場規(guī)模較大情況下才有經(jīng)濟(jì)性，否則就會(huì)出現(xiàn)剩余產(chǎn)品。

2、自由貿(mào)易對(duì)市場規(guī)模的擴(kuò)大有著積極的意義。斯密的報(bào)酬遞增觀點(diǎn)是新內(nèi)生經(jīng)濟(jì)增長理論的核心思想古典悲觀主義TP*TPOWsubsistencewagelinePE2W2W1E1N1N2LaborTotalproductionOriginalcondition:Labor:ON1Production:OPWage:N1W1Surplus:E1W1DemandforlaborincreaseWagesincreasetoE1N1>N1W1AccordingtoMalthusiantheoryofpopulation,populationwillincreasetoON2;SurplusappearagainE2W2Equilibriumpoint:ETechnologydevelopment:E*,thedayofdoomcannotbeeliminatedEE*LimitationsoftheclassicalmodelTheroleoftechnologydevelopmenthasbeengrosslyunderestimatedTheMalthusiantheoryofpopulationgrowthhasbeenprovedtobemisleading:wheneverwagesareabovelevelofsubsistence,populationwillincrease??TooaggregatedanddidnotaccountforthediversitieswithlaborandcapitalinputTheLinear-StagesTheoryRostow’sstagesofgrowthTheHarrod-DomargrowthmodelObstaclesandconstraintsSomecriticismsofthestagesmodelRostow’sstagesofgrowthTheTransitionfromunderdevelopmenttodevelopmentcanbedescriedintermsofaseriesofstepsorstagesthroughwhichallcountriesmustproceedthetraditionalsocietythepre-conditionsfortake-offintoself-sustaininggrowththetake-offthedrivetomaturitytheageofhighmass-consumption三種不同的增長率：實(shí)際增長率g;

有保證的增長率gw;

自然增長率gn實(shí)際增長率

TheHarrod-DomarModel(3.1)(3.2)(3.3)(3.4)v:capital-outputratio;S:savingratio;S:totalsaving;Y:totaloutput;K:capitalstock;I:totalinvestment有保證的增長率：這樣一種增長率將引誘投資剛好等于計(jì)劃的儲(chǔ)蓄，保持資本完全被就業(yè)，從而制造商愿意在未來以過去相同的比例進(jìn)行投資TheHarrod-DomarModel(3.5)(3.6)(3.7)Harrod-DomartheoryofeconomicgrowthTherateofgrowthofeconomicoutputIsdeterminedjointlybythenationalsavingratioSandnationalcapital-outputratioKThemainobstacleondevelopmentistherelativelylowlevelofnewcapitalformationinmostpoorcountriesJustifyingmassivetransfersofcapitalandtechnicalassistancefromdevelopedtolessdevelopednationsSavingandinvestmentisthenecessaryconditionforeconomicgrowthbutnotthesufficientconditionHowabouttheabilityofconvertingnewcapitaleffectivelyintohighlevelsofoutput

managerialcompetence;

skilledlabor;well-integratedcommodityandmoneymarket;institutionalsettings;infrastructuresCriticismofHarrod-DomarmodelStabilityofeconomicgrowth-

Harrodianknife-edge

保證均衡增長：g=gw一旦偏離均衡，即實(shí)際增長率與有保證增長率出現(xiàn)偏差，則這種偏離不會(huì)自行矯正，反而會(huì)加重如實(shí)際增長率低于有保證的增長率，在初期儲(chǔ)蓄率相同情況下，實(shí)際的資本產(chǎn)出比大于有保證的資本產(chǎn)出比，將出現(xiàn)資本品過剩，投資受到抑制，儲(chǔ)蓄率進(jìn)一步下降，投資受到抑制，使實(shí)際增長率更低于均衡增長率如實(shí)際增長率高于有保證的增長率，則實(shí)際的資本產(chǎn)出率低于有保證的資本產(chǎn)出率，資本品不足會(huì)刺激投資，導(dǎo)致實(shí)際增長率進(jìn)一步增大，更加偏離有保證的增長率，使得資本品更加不足Stabilityofeconomicgrowth-

Harrodianknife-edgeStabilityofeconomicgrowth-

Harrodianknife-edge黃金時(shí)代定理:actualgrowthrate=warrantedgrowthrate=naturalgrowthrateofthelaborforce.Thusn=s/visthenecessaryconditionforeconomicgrowth.

（JoanRobinson：GoldenAgerule，CambridgeUniversity）自然增長率-取決于勞動(dòng)力的增長速率和勞動(dòng)生產(chǎn)率的增長速率

Buts,vandnaredeterminedindependentlyandthereisnothingthatguaranteesthats/vwillbeequalton.thusthegoldenruleisveryhardtoachieve.Itisaknife-edgegrowthrate(veryunstablesystem,withnomechanismtobringtheeconomybacktotheequilibriumgrowthrate).Whentheeconomyisgrowingfast,itcontinuestogrowevenfasterandgoesbeyondfullemployment(i.e.highinflation),butwhengrowthisslow,itcontinuestogrowevenslower(i.e.highunemployment).發(fā)展中國家的情況自然增長率高于有保證的增長率意味著有效勞動(dòng)力增長高于資本積累速度，導(dǎo)致失業(yè)日益增長意味著計(jì)劃投資高于計(jì)劃儲(chǔ)蓄，產(chǎn)生通貨膨脹壓力要使自然增長率趨近有保證的增長率

1、控制人口規(guī)模

2、控制勞動(dòng)生產(chǎn)率增長幅度：效率與就業(yè)的沖突

3、提高儲(chǔ)蓄率

4、使用勞動(dòng)密集型技術(shù)降低所要求的資本－產(chǎn)出比NeoclassicalgrowthmodelIntheHarrod-Domargrowthmodel,steady-stategrowthwasunstable.Inthepopulartermoftheday,itwasa"knife-edge"inthesensethatanydeviationfromthatpathwouldresultinafurthermoveawayfromthatpathRobertM.Solow(1956),TrevorSwan(1956)andJamesE.Meade(1961)contestedthisconclusion.Theyclaimedthatthecapital-outputratiooftheHarrod-Domarmodelshouldnotberegardedasexogenous.Neoclassicalmodel:thecapital-outputratio,v,waspreciselytheadjustingvariablethatwouldleadasystembacktoitssteady-stategrowthpath,i.e.thatvwouldmovetobrings/vintoequalitywiththenaturalrateofgrowth(n).Theresultingmodelhasbecomefamouslyknownasthe"Solow-Swan"orsimplythe"Neoclassical"growthmodel.新古典增長理論的三個(gè)基本命題在長期穩(wěn)定狀態(tài)，產(chǎn)出的增長來自于有效的勞動(dòng)力增長率（即勞動(dòng)力的增長率加上勞動(dòng)生產(chǎn)率的增長率），與儲(chǔ)蓄率無關(guān)，更高的儲(chǔ)蓄或投資比率被更高的資本－產(chǎn)出比抵消。人均收入水平取決于儲(chǔ)蓄率或投資－GDP比率，與人口增長率呈反比。資本－勞動(dòng)比和資本生產(chǎn)率的反向關(guān)系使得發(fā)展中國家在人均資本數(shù)量較少的情況下?lián)碛懈叩亩唐诮?jīng)濟(jì)增長速率，各國的人均收入和生活水平應(yīng)該趨同。索羅模型1956年，開創(chuàng)性貢獻(xiàn)《對(duì)經(jīng)濟(jì)增長理論的一個(gè)貢獻(xiàn)》1987年，索羅獲得諾貝爾經(jīng)濟(jì)學(xué)獎(jiǎng)索羅模型的三個(gè)基本假定：

1、世界上每一個(gè)國家只生產(chǎn)和消費(fèi)相同商品；

2、國家與國家之間不存在貿(mào)易關(guān)系；

3、技術(shù)是外生的：公司可利用的技術(shù)游離于公司之外，不受公司行為的影響。索羅模型的三個(gè)技術(shù)假定

1、勞動(dòng)力以外生的不變速率增長

2、產(chǎn)出是勞動(dòng)和資本的函數(shù)，生產(chǎn)函數(shù)規(guī)模報(bào)酬不變，單個(gè)生產(chǎn)要素符合報(bào)酬遞減規(guī)律。

3、所有儲(chǔ)蓄都用于投資。基本索羅圖兩條曲線的差值：勞動(dòng)力人均資本的變化量；差值為正：人均資本增加，叫做“資本深化”差值為零：人均資本不變，人口增加帶來資本總量增加，叫做“資本拓寬”穩(wěn)定狀態(tài)：人均資本量保持不變(越過穩(wěn)態(tài)之后如何演變)比較靜態(tài)分析：模型參數(shù)變化對(duì)模型的影響投資率增加，資本進(jìn)一步深化，穩(wěn)定狀態(tài)下的勞動(dòng)力人均資本進(jìn)一步增加人口增長率增加，資本被稀釋，穩(wěn)定狀態(tài)下的勞動(dòng)力人均資本減少穩(wěn)定狀態(tài)的性質(zhì)人均資本存量隨時(shí)間變化率為零轉(zhuǎn)型動(dòng)態(tài)分析－從非穩(wěn)態(tài)向穩(wěn)態(tài)過渡過程中，經(jīng)濟(jì)增長速率的變化轉(zhuǎn)型動(dòng)態(tài)分析人均資本量的變化率：當(dāng)經(jīng)濟(jì)體低于其穩(wěn)定狀態(tài)越遠(yuǎn)，則增長率越大；經(jīng)濟(jì)體高于其穩(wěn)態(tài)越遠(yuǎn)，經(jīng)濟(jì)體衰退越快。穩(wěn)定狀態(tài)意味著增長停滯。Technologydevelopmentand

Solow’smodel引入技術(shù)進(jìn)步的索羅圖CharacteristicsofequilibriumpointAftertheequilibriumpoint,thegrowthofoutputperlaborisjointlydeterminedbytechnologydevelopmentratio,investmentratio,populationgrowthratio,depreciationratioofcapitalGrowthrate:sandninfluencetheabsolutelevelbutnotthegrowthrateoflong-termoutputperlaborttgt*t*Horizontaleffect勞動(dòng)力人均產(chǎn)出增長率隨時(shí)間的變化率在索羅模型中，投資率的上升會(huì)提高經(jīng)濟(jì)增長率，但它只能短期地存在于經(jīng)濟(jì)轉(zhuǎn)型到新地穩(wěn)定狀態(tài)地過程中，投資率地上升不會(huì)產(chǎn)生長期地增長效應(yīng)。投資率的上升會(huì)產(chǎn)生水平效應(yīng)，持續(xù)的投資率的上升或下降能夠持續(xù)地提高或降低人均產(chǎn)出的水平。索羅模型的評(píng)價(jià)造成人均收入差異的主要原因？各國不同的投資率、人口增長率、外生技術(shù)因素；富國投資率高而人口增長率低。經(jīng)濟(jì)持續(xù)增長的動(dòng)力？技術(shù)進(jìn)步克服了資本的邊際報(bào)酬遞減；長期一國的經(jīng)濟(jì)增長與技術(shù)增長同比率不同國家經(jīng)濟(jì)增長率的差異？外生的各國技術(shù)進(jìn)步的差異；同時(shí)利用轉(zhuǎn)型動(dòng)態(tài)分析可知在轉(zhuǎn)型動(dòng)態(tài)過程中，如果經(jīng)濟(jì)體的資本－技術(shù)比率低于其長期水平，則經(jīng)濟(jì)體以較快速度增長直至穩(wěn)定狀態(tài)Growt