MACROECONOMICS I March 14th, 2014 Class 4. The Solow-Swan Model (Cont.) The Solow-Swan Model: Population Growth • Labor force is growing at a constant rate n: Lt+1=(1+ n)Lt What happens to Capital/Labor ratio (k)? It is affect by investment (+), depreciation (-), and population growth (-) Law of motion for k? kt+1= sf(kt)+(1- ẟ - n)kt Solow-Swan Model: Population Growth (Cont.) Economies with high rates of population growth will have lower GDP per capita Government policy response? Population Growth: Summary Steady state: • Population growth increases Y and K (level effects) N!B! Both Y and K grow in the steady state at the rate n, but k* and y* are constant • Population growth reduces k* and y* Population growth consists of natural population increases + migration Population Growth Rates, 1985-1995 Source: The World Bank The Role of Technological Progress • Technological change, increase in factor productivity ü Larger output for given quantities of capital and labor Effective labor How does technological progress translates into larger output? • State of technology (A) Labor-augmenting technological progress • A as labor efficiency • TP reduced number of workers needed to produce the same output • TP increases output using the same number of workers The Solow-Swan Model with Technological Progress • Technology is improving every year at the exogenous rate (g) • • • Production function: GDP per effective labor The Solow-Swan Model with Technological Progress (Cont.) • From GDP per effective labor to the GDP per capita? • • • GDP per effective labor Capital per effective labor • We are interested in GDP per capita Steady state: Constant levels of capital and output per effective worker The Solow-Swan Model with Technological Progress (Cont.) The Solow-Swan Model: Technological Progress (Cont.) • Capital and output per effective worker are constant in steady state • What about per capita variables? GDP per capita grows at the rate of technological progress (sustainable growth) Balanced growth path: growth of variables at the same rate •Per capita variables (capital, output and consumption) grow at a constant rate g • Per effective labor variables are not growing in the steady state N!B! Solow model explains 60 % of cross-country variation of the GDP per capita by differences in savings rate and population growth Growth Accounting § Real GDP per capita growth rate for Czech Republic in 2011 was 1.7 % § Real GDP per capita growth rate for the USA in 2012 was 2.2 % How much of this growth is due to the factors’ accumulation and/or technology? Growth accounting: breakdown of observed growth of GDP into changes in inputs and technology Contribution of technology as a residual Growth Accounting (Cont.) • Capital (K) increases by 1 unit What is the effect on output Y? § § § § Marginal product of capita (MPK) TE Capital stock increased by 10 units and MPK =0.1. What is the impact on GDP? unit Growth Accounting (Cont.) • Labor (L) increases by 1 unit What is the effect on output Y? § § § § Marginal product of labor (MPL) TE Labor force increases by 10 units and MPK =0.3. units § Accounting for the increase in all components § § § How to account for the technological change? Solow Residual: the left-over growth of output when growth attributed to the changes in labor and capital is subtracted Solow Residual Calculate it as a residual Solow Residual (Cont.) § Where do we get marginal products of capital and labor? Mathematical manipulations • Transforming changes to growth rates GDP growth rate Unobservable technological change (g) Solow Residual (Cont.) Share of capital in output Share of labor in output N!B! Key assumption: Factors of production are paid their marginal product • Wages and rental rate of capital reflect productivity of factors Historical Factor Shares Labor (2/3) Capital (1/3) Source: Acemoglu, 2009 Source: Mankiw, 2009 The Asian Growth Miracle? A. Young (1995) QJE Exceptional growth due to changes in TFP or factor accumulation? The Asian Growth Miracle? Exceptional growth due to the factors accumulation? Conclusion? The miracle was bound to stop Asian Tigers: Performance After 1990s Source: IMF World Economic Outlook Database Real GDP growth rate Country Average growth rate 1990-2012 (%) Hong Kong 3.9 Singapore 5.9 South Korea 5 Taiwan 4.8 Asian Tigers: Performance After 1990s Global Slowdown in Economic Growth GDP per capita growth rate (% per year) Country 1948-1972 1972-1995 1995-2010 Canada 2.9 1.8 1.6 France 4.3 1.6 1.1 Germany 5.7 2 1.3 Italy 4.9 2.3 0.6 Japan 8.2 2.6 0.6 UK 2.4 1.8 1.7 USA 2.2 1.5 1.5 Source: Mankiw (2013) What are the reasons? Theories Explaining Disparities in Development Fundamental causes üGeography: geographical concentration of poverty and prosperity Tropical climate: lazy people, diseases, and poor agricultural lands Counter examples: Botswana, Nogales üCulture: beliefs, values, ethics, trust, cooperation Counter examples: North and South Korea üIgnorance of policy makers: poor policies Transfer of resources to a small powerful group The Institutional Hypothesis • Countries differ in economic success because of different institutions (rules) Laws, regulations, enforcement of property rights and social norms Extractive institutions: concentration of power in the hands of elite Inclusive institutions: inclusive markets and opportunities Free choice of occupation, education, constrained and broadly distributed power Institutions => Incentives to acquire education, start a business and innovate • Nogales African Growth Miracle GDP per capita Next class: Business cycles N!B! Homework is due next week before the class