Long-term economic growth Growth and factors of production

Transcription

1 Understanding the World Economy Master in Economics and Business Long-term economic growth Growth and factors of production Lecture 2 Nicolas Coeurdacier nicolas.coeurdacier@sciencespo.fr

2 Output per capita (constant USD) 25,000 What makes countries rich? A Tale of Two Countries 20,000 The average income on a Japanese person 15,000 10,000 5,000 The average income on a Ghanaian person

3 By 2000, Japan had more than 20 times the income of Ghana Three-quarters of Ghanaians have no access to health care; all Japanese do. Forty percent of all Ghanaians do not have clean drinking water; all Japanese do. Half of all Ghanaian women cannot read; all Japanese women can. Ghanaian mothers are 91 times more likely to die in childbirth than Japanese mothers.

4 Lecture 2 : Long-term economic growth Growth and factors of production 1. The Solow growth model 2. Do countries catch up with economic leaders? 3. The Asian growth miracle?

5 What are the engines of economic growth? The full picture is complicated and involves many different aspects. Next two lectures build up a complete picture. Focus first on just one factor - capital accumulation. Increases in the stock of physical capital (buildings and machinery). Stress many other things important not least how efficiently this capital stock is used. Capital is just a starting point.

6 Production function Output produced Buildings and machinery Labour input Technical knowledge and efficiency This lecture focuses on first input capital accumulation

7 Production function Output (at date t) is produced using inputs (capital and labour ) more or less efficiently. = (, ) Output increasing in the quantity of inputs, and. Output increasing in the efficiency of inputs (think technology ). Also called Total Factor Productivity (TFP).

8 Example: neoclassical production function = ( ) ( ) Constant returns to scale with respect to both inputs. Double and, double. Decreasing returns to scale to each input (0 < <1): each additional unit of input brings less and less output. Output per capita (with = =capital per capita): / = = ( / ) = ( )

9 Higher capital stock per capita increases output per capita Output per worker y = Capital per worker

10 Higher TFP increases output per capita Output per worker y = Capital per worker

11 How does capital accumulation work? How does increasing the capital stock lead to higher output? The marginal product of capital (MPK) is the increase in output that comes from increasing the capital stock leaving everything else unchanged The MPK can be : decreasing (Solow neoclassical model) each new machine adds less than the last constant (Endogenous Growth I AK) each new machines adds the same as the last increasing (Endogenous Growth II Poverty Trap) each new machine adds more than the last

12 THE RETURN ON CAPITAL Diminishing Marginal Product of Capital Return on Capital (MPK) 0 < <1 = () () = =A(/) Capital

13 THE RETURN ON CAPITAL Constant Marginal Product of Capital Return on Capital (MPK) =1 = K = =A Capital

14 Return on Capital (MPK) THE RETURN ON CAPITAL Increasing Marginal Product of Capital >1 = () () " = =A() () " Capital

15 The neoclassical MPK Assumptions about MPK purely technological no economics involved. Different assumptions may be needed for different technologies. We stick on decreasing returns - neoclassical production function with0<<1 andk = = capital per capita: = = A() Remark: Different assumptions lead to dramatically different implications. What would cross country growth patterns look like if MPK were initially increasing and then became decreasing?

16 The neoclassical production function Output per worker y { k } y 2 = { k } y1 y > y 1 2 Capital per worker

17 Will countries which invest more grow faster? Ultimately - No Short Term - Yes In long-run, investment affects only level not growth of output. To show this we need to add some economics to our technology assumption need to introduce investment.

18 The Solow growth model Production: = ( ) ( ) Capital accumulation: $ =(1 &) + ( &= depreciation rate; ( = investment ( = Savings = constant fraction s of income: ( =s =* ( ) ( ) Thus, capital obeys to: $ =(1 &) +* ( ) ( )

19 The Solow growth model: steady state $ =(1 &) +* ( ) ( ) Assuming for now constant and. In per capita terms: $ = 1 & +* ( ) $ =* ( ) & Steady-state defined as: $ = = & =* ( ) Steady-state capital and output per worker: =(,-. )/() ; = ( )

20 Steady-state capital stock per worker Steady state investment per worker / =& / = * Capital per worker

21 Convergence to the steady state When capital stock is low: Each new machine leads to a big increase in gross output The amount of output needed to replace machines that have worn out is low As a result net output increases with the capital stock When capital stock is (too) high: Each new machine leads to a small increase in gross output Every period a substantial part of output is needed to replace machines that have worn out Eventually net output decreases with capital stock Key to these results is decreasing marginal return on capital.

22 Higher savings increase the steady-state capital stock Steady state investment per worker / =& Higher * / = * Capital per worker

23 Investment Rate and Level of Per Capita Real GDP Log(GDP per capita) in Average Investment Rate Source: PWT

24 Savings or Investment? We are using investment and savings interchangeably If a country cannot borrow from overseas then its savings has to equal investment. Most countries do not borrow much from overseas (as a % of GDP) so savings and investment closely linked. When country borrows I > S but then it has to repay funds so S>I. Therefore on average I = S When country can borrow abroad (I > S), convergence towards steady-state can happen faster.

25 Higher TFP increases the steady-state capital stock Steady state investment per worker / =& Higher / =* Capital per worker

26 Optimal consumption and welfare A high savings rate leads to high income but low consumption A low savings rate leads to low income but high consumption Consumption per worker in the steady-state: 0 =(1 *) ( ) = 1 * ( * & )/() - + The Golden rule - level of savings that maximizes consumption in the steady state. Simple calculations suggest that optimal rate around 30-35% of GDP

27 Optimal consumption and welfare 0 =(1 *) ( ) = 1 * ( * & )/() 0 0% 100% *

28 Saving rates (% of GDP) Selected countries, average Source: World Bank Mozambique Senegal Rwanda United Kingdom Turkey Portugal United States Argentina Italy Brazil South Africa France Poland Spain Germany India Indonesia Switzerland China Singapore World

29 The Solow growth model: dynamics Steady-state: =(,-. )/() Dynamics: $ = 1 & +* ( ) $ =1( ) with =1( ) Convergence: converges to. As approaches, the growth rate of (and output ) decreases. The further away from a country is, the faster it grows.

30 Dynamics of the capital stock per worker $ $ = $ =1( ) 45 2

31 Implications of the Solow growth model 1. Countries always eventually reach their steady state 2. In the steady state/long run growth only comes from TFP. Countries at their steady state no longer grow from capital accumulation. Think of the OECD economies as those at their steady state. 3. Richer countries should grow slower than poorer ones: Higher returns on investment in poorer countries. Emerging markets are moving towards a steady state and growing fast. According to this story we would expect countries to catch up with economically most advanced nations

32 Catch up amongst Europe s big 4 GDP per capita (log-scale, USD) France Germany Italy UK Source: Maddison, GGDC and DataStream

33 Lecture 2 : Long-term economic growth Growth and factors of production 1. The Solow growth model 2. Do countries catch up with economic leaders? 3. The Asian growth miracle?

34 Output per worker growth (3 4 ) dynamics 3 4 Everything else equal, countries starting further away from their steady-state capital stock are growing at at a faster pace. Zero growth from capital accumulation 2

35 Do countries converge? According to the Solow growth model, poorer countries (in terms of capital stock per worker should) grow faster. Does it hold in the data? Investigate link between future growth and initial income per capita.

36 Do countries converge? The Evidence - Round I: The World If economies converge then expect negative correlation : countries with high GDP in 1960 should grow more slowly as capital earns a low return. Source: PWT

37 Do economies converge? The evidence - Round II: OECD Evidence for convergence is much stronger

38 Do economies converge? The evidence Round III: The States

39 Do economies converge? The evidence - Round IV: Japanese Prefectures

40 Do economies converge? The evidence - Round V: European Regions

41 Do economies converge? The evidence - Round VI: canadian provinces

42 Reconciling the evidence When we look at all economies no evidence of convergence. When we examine very similar countries strong evidence of convergence. How can we explain this mixed evidence concerning convergence? - take into account that steady states can differ across countries!

43 Conditional convergence The Solow model does not predict convergence unconditionally. Everything else equal, countries with lower capital stock should grow faster. Countries with same steady-state should converge = conditional convergence In particular, countries with lower TFP (or lower savings) should not catch-up. Importance for growth is distance from steady-state which can be different across countries.

44 Conditional convergence: an illustration Which country should grow faster? Steady state investment per worker ( =& * 56 =* 7898:8 * ;<89:8 Initial conditions: ;<89:8 < 56 = 7898:8 ;<89:8 < 7898:8 < 56 ;<89:8 7898:8 56 Capital per worker

45 Conditional convergence Only when countries share the same steady state should we see convergence. Explains why only see evidence for convergence amongst similar countries. Explains why many African countries do not catch up with Europe/U.S. Suggests that wealthier economies will persistently stay wealthier, but within wealthier economies should see evidence of catch up. The big question is what determines a countries steady state?

46 Estimating the steady state Convergence implies that growth increases with distance from steady-state: Don t have data on Y SS but assume GDP Growth = b (log(y SS )-log(y(0))), b>0 log(y SS )= a1 x Education + a2 x Health + a3 x Investment And can estimate for a cross-section of countries: GDP growth = b x (a1 x Education) + b x (a2 x health) + b x (a3 x Investment) b log(y(0)) If b> 0 then have support for convergence (conditionally on SS determinants) Can estimate if a1, a2, a3 are significantly different from zero and matter for steady state Typical cross-country growth regressions (initiated by Barro)

47 Dependent variable: real GDP per capita growth ( ), 100 countries. (in 1960) Source: Barro (1991)

48 I JUST RAN TWO MILLION REGRESSIONS (Salah-i-Martin (1997)) Always significant Frequently significant Often significant Sometimes significant Education Primary school Enrolment Regional dummies (Latin America, Sub Saharan Africa, Negative) Exchange Rate Overvaluation (Negative) Government Consumption (Negative) Investment Rule of Law Black market premiums (Negative) Health Life Expectancy Political Rights Primary Products (% exports Negative) Religious dummies (confucian, Muslim, Protestant) Openness Degree of Capitalism Financial Sophistication Inflation (Negative) Ethnic Diversity (Negative) Civil Liberties Revolutions, Coups, Wars (Negative) Religious dummies (Buddhism, Catholic) Public Investment

49 Lecture 2 : Long-term economic growth Growth and factors of production 1. The Solow growth model 2. Do countries catch up with economic leaders? 3. The Asian growth miracle?

50 Asian Tigers: growth miracle? Since the post-war period we have witnessed astonishing levels of growth in the Asian Tigers. The press and political commentators: Bad for the West: Take our jobs Western leaders and CEO s should look at the Tigers and learn how to improve efficiency. Economists: No growth miracle. Just accumulation of inputs.

51 Average Growth GDP per capita Germany Mexico US Canada France Brazil Italy Chile Japan Singapore HongKong China Korea Taiwan 0% 1% 2% 3% 4% 5% 6% 7% Source : Penn WT 6.3 and DataStream.

52 Saving rates (% of GDP) Singapore China South Korea Hong Kong Source: World Bank

53 Growth Accounting = ( ) ( ) Take log- of both sides and first time difference: =log - +(1 3 = (1 )3 Output growth 3 comes from TFP growth 3 - and growth in inputs3 and3. Output per capita: = ( ) 3 4 = C

54 TFP 40% Growth Accounting for Asian Dragons Employment TFP 18% -4% Employment 38% Hong Kong Capital 62% Capital 42% Employment TFP 17% 23% Employment TFP 19% 28% Singapore Korea Taiwan Capital 59% Source : Young 1995, Barro and Sala-I-Martin 1991 Capital 53%

55 Asian Tigers: growth miracle? Some differences in the sources of growth. BUT: Increased capital stock MOST important factor for all of them. Krugman: Perspiration rather than inspiration! Too rapid development? No gains from the learning curve? Incorrect balance between innovation and experience? Does it matter? No: They got much richer anyway Yes: Some have paid for it - those that were young early on in the process: Low income, high savings Future? Need to shift from extensive to intensive margin

56 Summary Countries show enormous differences in their standards of living. Further some poor countries have shown rapid growth while others have remained poor. The neoclassical (Solow) growth model focuses on explaining these differences through capital accumulation, assuming decreasing marginal product of capital. This assumption should imply convergence. Countries with high investment rates have a high steady state and are rich. At the steady state all countries grow at the rate of technological progress. The Solow model relies on conditional convergence conditional on countries sharing the same steady state then poorer countries will grow faster than rich ones. The steady state depends on many factors. Strong roles are found for education, health and rate of investment but many other additional variables are also found important. The analysis suggests that making a country rich will involve a broad package of economic, social and political policies don t look for magic ingredient X.