巴罗宏观经济学：现代观点第3章.ppt
Macroeconomics Chapter 3,1,Introduction to Economic Growth,C h a p t e r 3,Macroeconomics Chapter 3,2,Economic Growth and Standard of Living,Macroeconomics Chapter 3,3,World Distribution of Real GDP,World Distribution of Per Capita income in 2000World Distribution of Per Capita Income in 1960Growth Rate in Per capita Income 1960-2000.Income Inequality.,Macroeconomics Chapter 3,4,Macroeconomics Chapter 3,5,Macroeconomics Chapter 3,6,Macroeconomics Chapter 3,7,Macroeconomics Chapter 3,8,Macroeconomics Chapter 3,9,Long Term Economic Growth in OECD Countries,Macroeconomics Chapter 3,10,Productivity Slowdown,The 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.,Macroeconomics Chapter 3,11,Growth Questions,What 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?,Macroeconomics Chapter 3,12,Growth Questions,How 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?,Macroeconomics Chapter 3,13,Growth Questions,What can policymakers do to increase growth rates of real GDP per person?,Macroeconomics Chapter 3,14,Production Function,Y=A F(K,L)A Technology LevelK Capital Stock machines and buildings used by business.L Labor Force number of workers,Macroeconomics Chapter 3,15,Macroeconomics Chapter 3,16,Macroeconomics Chapter 3,17,Production Functions,MPL Marginal Product of LaborDiminishing Marginal Product of laborMPK Marginal Product of CapitalDiminishing Marginal Product of Capital,Macroeconomics Chapter 3,18,Constant Returns to Scale,Constant Returns to ScaleDouble 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),Macroeconomics Chapter 3,19,Per Worker Production Function,y=f(k)y output per workerk capital per worker,Macroeconomics Chapter 3,20,Macroeconomics Chapter 3,21,An example:Cobb-Douglas Production Function,Macroeconomics Chapter 3,22,Contributions to GDP Growth,Y/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 residual,Macroeconomics Chapter 3,23,Contributions to GDP Growth,+=1 Share of capital income()+share of labor income()=1Y/Y=A/A+(K/K)+(L/L)0 10 1,Macroeconomics Chapter 3,24,Solow Growth Model,Model ignores:GovernmentNo taxes,public expenditures,debt,or moneyInternational TradeNo trade in goods or financial assets,Macroeconomics Chapter 3,25,Solow Growth Model,Labor force,L=(labor force/population)populationLabor-force participation rateAssume labor force participation rate is constant.Labor force growth rate is the population growth rate,Macroeconomics Chapter 3,26,Solow Growth Model,Growth rate in populationWe assume that population grows at a constant rate,denoted by n,where n is a positive number(n 0).L/L=n,Macroeconomics Chapter 3,27,Solow Growth Model,Macroeconomics Chapter 3,28,Solow Growth Model,Assume 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.,Macroeconomics Chapter 3,29,Solow Growth Model,From the per worker production function y/y=Y/Y L/Lk/k=K/K L/L,Macroeconomics Chapter 3,30,Solow 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),Macroeconomics Chapter 3,31,Solow Growth Model,Each 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 year,Macroeconomics Chapter 3,32,Solow Growth Model,Real saving=s(Y K)Real saving=(saving rate)(real income),Macroeconomics Chapter 3,33,Solow Growth Model,YK=C+s(Y K)Real income=consumption+real saving,Macroeconomics Chapter 3,34,Solow Growth Model,Y=C+IReal GDP=consumption+gross investmentYK=C+(IK)Real NDP=consumption+net investment,Macroeconomics Chapter 3,35,Solow Growth Model,C+s(YK)=C+IKors(YK)=IKReal saving=net investment,Macroeconomics Chapter 3,36,Solow Growth Model,K=IKChange in capital stock=gross investment depreciation,or Change in capital stock=net investment K=s(YK)Change in capital stock=real saving,Macroeconomics Chapter 3,37,Solow Growth Model,Divide both sides by K K/K=sY/K s,Macroeconomics Chapter 3,38,Solow Growth Model,k/k=K/K L/Lk/k=s(Y/K)s n,Macroeconomics Chapter 3,39,Solow Growth Model,Y/K=(Y/L)/(K/L)Y/K=y/k,Macroeconomics Chapter 3,40,Solow Growth Model,k/k=s(y/k)s ny/y=(k/k)y/y=s(y/k)s n,Macroeconomics Chapter 3,41,Solow Growth Model,Macroeconomics Chapter 3,42,Solow Growth Model,Macroeconomics Chapter 3,43,Solow Growth Model,steady state.When k=k,k/k equals zero.k/k=0,k stays fixed at the value k.y*=f(k*),Macroeconomics Chapter 3,44,Solow Growth Model,Macroeconomics Chapter 3,45,Solow Growth Model,In 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 worker,
