《高级宏观经济学(2)》课件-4

A Introduction to Growth Theory

1The Importance of Economic Growth

The Significance of1%Growth in GDP

Growth Rate(%)1075 2.51

Time to Double Income(Years)7.310.214.228.169.7

2Some Stylized Facts about Economic Growth(Kaldor, 1963)

•Per capita output grows over time,and its growth rate does not tend to diminish.

•Physical capital per worker grows over time.

•The ratio of physical capital to output is nearly constant.

•The shares of labor and physical capital in national income are nearly constant.

•Per capita output differs substantially across countries.

•The growth rate of per capita output varies greatly across coun-tries and over time.3Development of growth theory

3.1Classical Growth Theories

•Adam Smith(1776)and David Ricardo(1817)

•Thomas Malthus(1798)

•Frank Ramsey(1928)

•Joseph Schumpeter(1934)

3.2Neoclassical Growth Models

(i)Solow-Swan Model(1956)

•Constant returns to scale

•Diminishing returns to each input

•Fixed savings rate

•Exogenous technological progress

•No technological progress⇒no growth in per capita income •(Transitional dynamics)Lower starting level of real per capita GDP⇒higher growth rate

•Dynamic inefficiency(ii)Cass and Koopmans Model(1965)

•Endogenous savings rate

•Competitive equilibrium–Pareto optimal

3.3Early Attempts to Endogenize Technological Progress

(i)Arrow Model(1962)

•Learning-by-doing

•Technological progress–unintended by-product of production or investment

•No compensation is paid to technological progress and capital and labor receive their marginal products

•Technological progress is endogenous(in the sense that saving propensity affects its time path)

(ii)Uzawa Model(1965)

•Optimal accumulation of physical and human capital

•No compensation is paid to technological progress(iii)Shell Model(1967)

•Government-financed R&D

•Technological progress is modeled as a result of economic choices •Strictly decreasing returns

•No growth in per capita income

3.4Endogenous Growth Models

•Long-run growth rate is endogenously determined

(i)Capital-based Models

•Physical and/or human capital accumulation⇒economic growth •Emphasize externalities of capital accumulation

(ii)Innovation-based Models

•Innovation⇒technological progress⇒economic growth •Stress intentional R&D activities

(iii)Other Endogenous Growth Models