北京大学樊纲发展经济学6.ppt

1、Ch.3. Dual-economy Models and Structure changes in growth,Lewis Model,Key issue of growth with Industrialization is the reallocation of labor from agriculture or “traditional” sector to non-farming, “modern” industries. Unemployment or under-employment in Traditional sector; Income (wage) in modern

2、sector is higher; Laborers are reallocated to modern sector because they are attracted by higher wages; Modern sector enjoys infinite supply of labor at constant wage ( Wi subsistence wage, Ws ) , for a period of time.,Start of take off,An industry emerges which productivity is higher than tradition

3、al sector, because of one or more of following reasons: An innovation; A reform New market: Start to export Open to FDI; Or a colonial invasion.,The labor supply curves,Classical: Karl Marx Neo-classical: A. Marshall Lewis: Turning point from one world to another,Extra Growth and Extra Profit,Higher

4、 profit,The extra profit as Wi = MRL at LL , there is a compared to Lw When wage is fixed but labor productivity increases, every year there is more extra profit; Compounded in time, it could be very high: the longer it exists, the higher it can be.,Higher Savings, S W for consumption Return to capi

5、tal for savings,Higher investment and growth,Key factor: at Wi = MRL, there is a S I G L (reallocation) Lewis Model is about reallocation of labor from traditional sectors, not about the “demographic dividend”.,FDI and capital inflows,The higher profits also attract foreign capital to come in.,Incom

6、e Disparity,Wi Ws enlargement of income gaps,“Lewis Turning Point”,“Lewis Turning Point” as a process,T1: Wi start to increase because decreasing surplus labor and therefore increase of farmers income. T2: Ws = Wi and increase together and and LSL LSL - the fundamental condition of the LTP is the eq

7、ualization of wages between industries!,Lewis Turning Point(s),Why Wa (or Ws) increases?,With less and less laborers in agriculture, land per capita increases, so Wa increases. With land per capita increases, modern tech. applied so productivity increases.,Summary,Classical world vs. Neo-classical w

8、orld; Labor Productivity increase and Profitability; High profit, high saving, high investment, high growth Income disparity;,Other Issues,High Savings and low consumption, before LTP; External imbalance because domestic imbalances.,The Case of China,Chinas Structural Problem,Various sectors as % of

9、 total savings,Chinas Saving Rate (GDP),Household sector savings rate,Contributors to Chinas Saving,Wage as % of GDP,Households disposable income / other incomes,Labor Productivity and trade Surplus,Other Structural Changes,Empirical Structural Typology models,Kuznets: 1. The growth may be caused by

10、 different productivities in different sectors; 2. structural changes indicate the growth/modernization - the relationship of agriculture, manufacture, service sectors.,Walt W. Rostows “Stages of economic growth”,Traditional society; Preparation for take-off: infrastructures, basic education, savings, . Take-off, sustained growth; Ma