[經(jīng)濟學(xué)]發(fā)展經(jīng)濟學(xué)(3)ppt課件

1、Theories of Development: A Comparative AnalysisChapter 3Leading Theories of Economic Development: Five ApproachesnClassical Scenario 古典經(jīng)濟增長實際nLinear-stages-of-growth modeln 線性增長模型nNeoclassical modelsn 新古典增長模型nEndogenous growthn 內(nèi)生經(jīng)濟增長模型亞當(dāng)斯密與報酬遞增n產(chǎn)出、生活程度提高資本積累利潤的儲蓄工業(yè)和農(nóng)業(yè)的專業(yè)化勞動分工n勞動分工決議了勞動消費率。n 勞動分工提高勞

2、動消費率有三種途徑：n 1、工人任務(wù)技藝的提升，即邊干邊學(xué)。n 2、分工的細(xì)化節(jié)省了在不同任務(wù)間轉(zhuǎn)移的時間。n 3、機器的發(fā)明使同一個勞動者可以從事多種任務(wù)。n勞動分工遭到市場規(guī)模的限制。n 1、如機器的運用只需在市場規(guī)模較大情況下才有經(jīng)濟性，否那么就會出現(xiàn)剩余產(chǎn)品。n 2、自在貿(mào)易對市場規(guī)模的擴展有著積極的意義。n斯密的報酬遞增觀念是新內(nèi)生經(jīng)濟增長實際的中心思想古典悲觀主義TP*TPOW subsistence wage linePE2W2W1E1N1 N2LaborTotal productionOriginal condition:Labor: ON1Production: OPWage

3、:N1W1Surplus:E1W1Demand for labor increaseWages increase to E1N1N1W1According to Malthusian theory of population, population will increase to ON2;Surplus appear again E2W2Equilibrium point: ETechnology development: E*, the day of doom can not be eliminatedEE*Limitations of the classical model nThe r

4、ole of technology development has been grossly underestimatednThe Malthusian theory of population growth has been proved to be misleading: whenever wages are above level of subsistence, population will increase?nToo aggregated and did not account for the diversities with labor and capital inputThe L

5、inear-Stages TheorynRostows stages of growthnThe Harrod-Domar growth modelnObstacles and constraintsnSome criticisms of the stages modelRostows stages of growthnThe Transition from underdevelopment to development can be descried in terms of a series of steps or stages through which all countries mus

6、t proceedn the traditional societyn the pre-conditions for take-off into self-sustaining growthn the take-offn the drive to maturityn the age of high mass-consumptionn三種不同的增長率：n 實踐增長率g;n 有保證的增長率gw;n 自然增長率gnn實踐增長率n The Harrod-Domar Model增量資本產(chǎn)出比率儲蓄率 /)/()/(/I/K/YcYSscsYIYSYYg)( 潛在投資供給）計劃儲蓄sYS KI 投資需求(

7、3.1)(3.2)YvK(3.3)IS 動態(tài)均衡(3.4)v: capital-output ratio; S: saving ratio; S: total saving; Y: total output;K: capital stock; I: total investmentn有保證的增長率：這樣一種增長率將誘惑投資剛好等于方案的儲蓄，堅持資本完全被就業(yè)，從而制造商情愿在未來以過去一樣的比例進展投資The Harrod-Domar ModelIKYvsYS(3.5)YvsY(3.6)wgvsYY(3.7)Harrod-Domar theory of economic growthnThe

8、 rate of growth of economic output I s determined jointly by the national saving ratio S and national capital-output ratio KnThe main obstacle on development is the relatively low level of new capital formation in most poor countriesnJustifying massive transfers of capital and technical assistance f

9、rom developed to less developed nationsnSaving and investment is the necessary condition for economic growth but not the sufficient conditionnHow about the ability of converting new capital effectively into high levels of outputn managerial competence;n skilled labor;n well-integrated commodity and

10、money market;n institutional settings;n infrastructuresCriticism of Harrod-Domar modelStability of economic growth-Harrodian knife-edgen保證平衡增長：g=gwn一旦偏離平衡，即實踐增長率與有保證增長率出現(xiàn)偏向，那么這種偏離不會自行矯正，反而會加重n照實踐增長率低于有保證的增長率，在初期儲蓄率一樣情況下，實踐的資本產(chǎn)出比大于有保證的資本產(chǎn)出比，將出現(xiàn)資本品過剩，投資遭到抑制，儲蓄率進一步下降，投資遭到抑制，使實踐增長率更低于平衡增長率n照實踐增長率高于有保證的增

11、長率，那么實踐的資本產(chǎn)出率低于有保證的資本產(chǎn)出率，資本品缺乏會刺激投資，導(dǎo)致實踐增長率進一步增大，更加偏離有保證的增長率，使得資本品更加缺乏Stability of economic growth-Harrodian knife-edgeStability of economic growth-Harrodian knife-edgen黃金時代定理: actual growth rate = warranted growth rate = natural growth rate of the labor force. Thus n = s/v is the necessary conditio

12、n for economic growth. n Joan Robinson： Golden Age rule ，Cambridge Universityn自然增長率-取決于勞動力的增長速率和勞動消費率的增長速率n )/()/(/)/log(loglog)/(LYLYLLYYLYLYLYLYnBut s, v and n are determined independently and there is nothing that guarantees that s/v will be equal to n. thus the golden rule is very hard to achiev

13、e. nIt is a knife-edge growth rate (very unstable system, with no mechanism to bring the economy back to the equilibrium growth rate). nWhen the economy is growing fast, it continues to grow even faster and goes beyond full employment (i.e. high inflation), but when growth is slow, it continues to g

14、row even slower (i.e. high unemployment). 開展中國家的情況n自然增長率高于有保證的增長率n意味著有效力動力增長高于資本積累速度，導(dǎo)致失業(yè)日益增長n意味著方案投資高于方案儲蓄，產(chǎn)生通貨膨脹壓力n要使自然增長率趨近有保證的增長率n 1、控制人口規(guī)模n 2、控制勞動消費率增長幅度：效率與就業(yè)的沖突n 3、提高儲蓄率n 4、運用勞動密集型技術(shù)降低所要求的資本產(chǎn)出比Neoclassical growth modelnIn the Harrod-Domar growth model, steady-state growth was unstable. In the

15、 popular term of the day, it was a knife-edge in the sense that any deviation from that path would result in a further move away from that path nRobert M. Solow (1956), Trevor Swan (1956) and James E. Meade (1961) contested this conclusion. They claimed that the capital-output ratio of the Harrod-Do

16、mar model should not be regarded as exogenous. nNeoclassical model : the capital-output ratio, v, was precisely the adjusting variable that would lead a system back to its steady-state growth path, i.e. that v would move to bring s/v into equality with the natural rate of growth (n). The resulting m

17、odel has become famously known as the Solow-Swan or simply the Neoclassical growth model. 新古典增長實際的三個根本命題n在長期穩(wěn)定形狀，產(chǎn)出的增長來自于有效的勞動力增長率即勞動力的增長率加上勞動消費率的增長率，與儲蓄率無關(guān)，更高的儲蓄或投資比率被更高的資本產(chǎn)出比抵消。n人均收入程度取決于儲蓄率或投資GDP比率，與人口增長率呈反比。n資本勞動比和資本消費率的反向關(guān)系使得開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)濟增長速率，各國的人均收入和生活程度應(yīng)該趨同。索羅模型n1956年，開創(chuàng)性奉獻n1987

18、年，索羅獲得諾貝爾經(jīng)濟學(xué)獎n索羅模型的三個根本假定：n 1、世界上每一個國家只消費和消費一樣商品；n 2、國家與國家之間不存在貿(mào)易關(guān)系；n 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。n索羅模型的三個技術(shù)假定n 1、勞動力以外生的不變速率增長n 2、產(chǎn)出是勞動和資本的函數(shù)，消費函數(shù)規(guī)模報酬不變，單個消費要素符合報酬遞減規(guī)律。n 3、一切儲蓄都用于投資。KYKFLYKLLFLKLKFLKLKFY/)1 ()1 (/),(P ),(1本租金率直到其邊際產(chǎn)出等于資資本使用量持續(xù)增加，其邊際產(chǎn)出等于工資勞動力持續(xù)增加，直到利潤最大化條件：利潤函數(shù)資本租金資本價格：工人工資勞動

19、力價格：一、生產(chǎn)函數(shù)索羅模型兩個重要函數(shù)遞減的均資本該函數(shù)說明：則有：新表述：和人均資本使用量來重將生產(chǎn)函數(shù)用人均產(chǎn)出加是所帶帶來的產(chǎn)出，人每增加一個單位勞動力報酬是遞減的：勞動力人均資本的規(guī)模/;/kyLKkLYyky 表示固定的資本折舊率：表示資本折舊量，投資；閉的，所有儲蓄都用于儲蓄，由于經(jīng)濟體是封序率進行假定工人按照固定的程：表示總投資量，索羅變化；表示相鄰期資本存量的二、資本積累函數(shù)索羅模型兩個重要函數(shù)ddKsYdtdKKdKsYdtdKK:/)3( /)(2) /loglog) 1 ( /logloglog/0nLLeLtLkkyykykyLLKKkkLKkLKknt長，勞動力以固

20、定比率增根據(jù)索羅模型技術(shù)假定先取對數(shù)再求導(dǎo)：一個小技巧：人均資本表示的形式：將資本積累函數(shù)轉(zhuǎn)化為dnksydnKsYkk/31）帶入資本積累函數(shù)）和（將方程（kdnsykkykdnsyk）（程：索羅模型的兩個核心方減少隨著勞動力數(shù)量增加而舊的增加而減少；隨著勞動力人均資本折的增加而增加；隨著勞動力人均投資量：勞動力人均資本的變化）（的資本積累方程為以勞動力人均形式表示根本索羅圖必需新增的人均資本量為保持人均資本不變所的情況下對人均資本的稀釋作用數(shù)量增加考慮資本折舊和勞動力, )(kdn人均投資量 sksy *0kkkn兩條曲線的差值：勞動力人均資本的變化量；n差值為正：人均資本添加，叫做“資本

21、深化n差值為零：人均資本不變，人口添加帶來資本總量添加，叫做“資本拓寬n穩(wěn)定形狀：人均資本量堅持不變(越過穩(wěn)態(tài)之后如何演化)比較靜態(tài)分析：模型參數(shù)變化對模型的影響kdn)( skys * *0kkkkskys投資率添加，資本進一步深化，穩(wěn)定形狀下的勞動力人均資本進一步添加kdn)( skys * *kkkkdn)(人口增長率添加，資本被稀釋，穩(wěn)定形狀下的勞動力人均資本減少穩(wěn)定形狀的性質(zhì)n人均資本存量隨時間變化率為零加同步經(jīng)濟總量增加與人口增均產(chǎn)出沒有增加，穩(wěn)定狀態(tài)下，勞動力人動力人均資本量較低。人口增長率較高國家勞人均產(chǎn)出量較高；動力人均資本量較高，儲蓄投資率較高國家勞）（)1/()1/(1)

22、/()/(0dnsydnskkdnsyk轉(zhuǎn)型動態(tài)分析從非穩(wěn)態(tài)向穩(wěn)態(tài)過渡過程中，經(jīng)濟增長速率的變化 *kkdn資本的平均產(chǎn)出遞減 /1skksy)()(/1dnskdnkyskk轉(zhuǎn)型動態(tài)分析n人均資本量的變化率：當(dāng)經(jīng)濟體低于其穩(wěn)定形狀越遠(yuǎn)，那么增長率越大；經(jīng)濟體高于其穩(wěn)態(tài)越遠(yuǎn)，經(jīng)濟體衰退越快。n穩(wěn)定形狀意味著增長停滯。Technology development and Solows modelA/)1 (/,:/K/:/A : )(101AkkyyAkydKsYKeAAgAAAALKYgt求導(dǎo)對等式兩邊先取對數(shù)再生產(chǎn)函數(shù)資本積累函數(shù)型的兩個基本函數(shù)引入技術(shù)進步后索羅模濟體之外產(chǎn)生是外生變量，獨

23、立于經(jīng)步或哈羅德中性的技術(shù)進勞動增強的技術(shù)進步技術(shù)進步變量，被稱為kdgnyskdKsYKKLLAAKKkkkyALKkgggkykyky)(/ /- - /:;,/,Y/K;,Y/K帶入資本積累方程技術(shù)比率稱為產(chǎn)出技術(shù)比率技術(shù)比率，稱之為資本勞動力人均資本則平衡增長路徑被稱為比例增長的情形人口和消費按相同固定產(chǎn)出資本以相同比率增長和則也一定一定時當(dāng)資本的變化率為常數(shù)一定時出當(dāng)且僅當(dāng)資本的平均產(chǎn)平衡經(jīng)濟增長路徑引入技術(shù)提高的索羅圖kdgn)(ys *0kkkCharacteristics of equilibrium point111111)()()()()()( )(0 :point meq

24、uilibriudgnstAAytydgnsydgnstAAkkdgnskk After the equilibrium point, the growth of output per labor is jointly determined by technology development ratio, investment ratio, population growth ratio, depreciation ratio of capitalnGrowth rate:ns and n influence the absolute level but not the growth rate

25、 of long-term output per laborgggky *kkkdgn1ks1ks)(/dgnkyskktyy /ylogtgt*t*Horizontal effect勞動力人均產(chǎn)出增長率隨時間的變化率n在索羅模型中，投資率的上升會提高經(jīng)濟增長率，但它只能短期地存在于經(jīng)濟轉(zhuǎn)型到新地穩(wěn)定形狀地過程中，投資率地上升不會產(chǎn)生長期地增長效應(yīng)。n投資率的上升會產(chǎn)生程度效應(yīng)，繼續(xù)的投資率的上升或下降可以繼續(xù)地提高或降低人均產(chǎn)出的程度。索羅模型的評價n呵斥人均收入差別的主要緣由？n 各國不同的投資率、人口增長率、外生技術(shù)要素；富國投資率高而人口增長率低。n經(jīng)濟繼續(xù)增長的動力？n 技術(shù)提高抑制

26、了資本的邊沿報酬遞減；長期一國的經(jīng)濟增長與技術(shù)增長同比率n不同國家經(jīng)濟增長率的差別？n 外生的各國技術(shù)提高的差別；同時利用轉(zhuǎn)型動態(tài)分析可知在轉(zhuǎn)型動態(tài)過程中，假設(shè)經(jīng)濟體的資本技術(shù)比率低于其長期程度，那么經(jīng)濟體以較快速度增長直至穩(wěn)定形狀Growth accountingty(TFP)ProductiviFactor Total as defined is / Where/)1 (/1BBBBLLKKYYLBKYGrowth rate of GDPContribution to growthGrowth rate of GDP per laborcapitallaborTFP1960-19704.00.81.21.92.21970-19802.70.91.50.20.41980-19902.60.80.71.01.5196