巴罗宏观经济学：现代观点第3章.ppt

Introduction to Economic GrowthC h a p t e r 31Macroeconomics Chapter 3Economic Growth and Standard of Living2Macroeconomics Chapter 3World Distribution of Real GDPWorld Distribution of Per Capita income in 2000World Distribution of Per Capita Income in 1960Growth Rate in Per capita Income 1960-2000.Income Inequality.3Macroeconomics Chapter 34Macroeconomics Chapter 35Macroeconomics Chapter 36Macroeconomics Chapter 37Macroeconomics Chapter 38Macroeconomics Chapter 3Long Term Economic Growth in OECD Countries9Macroeconomics Chapter 3Productivity SlowdownThe decline in the growth rate of real GDP per person from 3.1%per year for 19601980 to 1.8%per year for 19802000 is sometimes called the productivity slowdown.10Macroeconomics Chapter 3Growth QuestionsWhat factors caused some countries to grow fast and others to grow slow over periods such as 1960 to 2000?In particular,why did the East Asian countries do so much better than the sub-Saharan African countries?11Macroeconomics Chapter 3Growth QuestionsHow did countries such as the United States and other OECD members sustain growth rates of real GDP per person of around 2%per year for a century or more?12Macroeconomics Chapter 3Growth QuestionsWhat can policymakers do to increase growth rates of real GDP per person?13Macroeconomics Chapter 3Production FunctionY=A F(K,L)lA Technology LevellK Capital Stock machines and buildings used by business.lL Labor Force number of workers14Macroeconomics Chapter 315Macroeconomics Chapter 316Macroeconomics Chapter 3Production FunctionsMPL Marginal Product of LaborlDiminishing Marginal Product of laborMPK Marginal Product of CapitallDiminishing Marginal Product of Capital17Macroeconomics Chapter 3Constant Returns to ScaleConstant Returns to ScalelDouble K and L and Y will also doubleTherefore,if we multiply K and L by the quantity 1/L we also multiply Y by 1/L to getY/L=A F(K/L,L/L)18Macroeconomics Chapter 3Per Worker Production Functiony=f(k)ly output per workerlk capital per worker19Macroeconomics Chapter 320Macroeconomics Chapter 3An example:Cobb-Douglas Production Function21Macroeconomics Chapter 3Contributions to GDP GrowthY/Y=A/A+(K/K)+(L/L)The growth rate of real GDP,Y/Y,equals the growth rate of technology,A/A,plus the contributions from the growth of capital,(K/K),and labor,(L/L).Solow residual22Macroeconomics Chapter 3Contributions to GDP Growth+=1 Share of capital income()+share of labor income()=1Y/Y=A/A+(K/K)+(L/L)l0 1l0 0).L/L=n26Macroeconomics Chapter 3Solow Growth Model27Macroeconomics Chapter 3Solow Growth ModelAssume A/A=0Y/Y=(K/K)+(1)(L/L)The growth rate of real GDP is a weighted average of the growth rates of capital and labor.28Macroeconomics Chapter 3Solow Growth ModelFrom the per worker production function ly/y=Y/Y L/Llk/k=K/K L/L29Macroeconomics Chapter 3Solow Growth Model Y/Y=(K/K)+(1)(L/L)Y/Y=(K/K)(L/L)+L/LY/Y L/L=(K/K L/L)y/y=(k/k)30Macroeconomics Chapter 3Solow Growth ModelEach household divides up its real income in a fixed proportion s to saving and 1 s to consumption(C).Capital depreciate at the same constant rate K is the amount of capital that depreciates each year31Macroeconomics Chapter 3Solow Growth ModelReal saving=s (Y K)Real saving=(saving rate)(real income)32Macroeconomics Chapter 3Solow Growth ModelYK=C+s(Y K)Real income=consumption+real saving33Macroeconomics Chapter 3Solow Growth ModelY=C+IReal GDP=consumption+gross investmentYK=C+(IK)Real NDP=consumption+net investment34Macroeconomics Chapter 3Solow Growth ModelC+s(YK)=C+IKors(YK)=IKReal saving=net investment35Macroeconomics Chapter 3Solow Growth ModelK=IKChange in capital stock=gross investment depreciation,or Change in capital stock=net investment K=s(YK)Change in capital stock=real saving36Macroeconomics Chapter 3Solow Growth ModelDivide both sides by K K/K=sY/K s37Macroeconomics Chapter 3Solow Growth Modelk/k=K/K L/Lk/k=s(Y/K)s n38Macroeconomics Chapter 3Solow Growth ModelY/K=(Y/L)/(K/L)Y/K=y/k39Macroeconomics Chapter 3Solow Growth Model k/k=s(y/k)s ny/y=(k/k)y/y=s(y/k)s n40Macroeconomics Chapter 3Solow Growth Model41Macroeconomics Chapter 3Solow Growth Model42Macroeconomics Chapter 3Solow Growth Modelsteady state.lWhen k=k,k/k equals zero.lk/k=0,k stays fixed at the value k.y*=f(k*)43Macroeconomics Chapter 3Solow Growth Model44Macroeconomics Chapter 3Solow Growth ModelIn the steady state,k/k equals zero.s(y*/k*)s n=0s(y*k*)=nk*Steady-state saving per worker=steady-state capital provided for each new worker45Macroeconomics Chapter 3