ofEconomicGrowth宏观经济学-加州大学-詹姆斯·

1、CHAPTER 4The Theory of Economic Growth1QuestionsWhat are the principal determinants of long-run economic growth?What equilibrium condition is useful in analyzing long-run growth?How quickly does an economy head for its steady-state growth path?2QuestionsWhat effect does faster population growth have

2、 on long-run growth?What effect does a higher savings rate have on long-run growth?3Long-Run EconomicGrowth.is the most important aspect of how the economy performscan be accelerated by good economic policiescan be retarded by bad economic policies4Long-Run Economic GrowthPolicies and initial condit

3、ions affect growth through two channelstheir impact on the level of technologymultiplies the efficiency of labortheir impact on the capital intensity of the economythe stock of machines, equipment, and buildings that the average worker has at his or her disposal5Technologyleads to a higher efficienc

4、y of laborskills and education of the labor forceability of the labor force to handle modern machinesthe efficiency with which the economys businesses and markets functionEconomists are good at analyzing the consequences of better technologyhave less to say about the sources 6Capital IntensityThere

5、is a direct relationship between capital-intensity and productivityTwo principal determinantsinvestment effortthe share of total production saved and invested in order to increase the capital stockinvestment requirementshow much of new investment is used to equip new workers with the standard level

6、of capital or to replace worn-out or obsolete capital7Standard Growth ModelAlso called the Solow modelSteady-state balanced-growth equilibriumthe capital intensity of the economy is stablethe economys capital stock and level of real GDP are growing at the same ratethe economys capital-output ratio i

7、s constant8Standard Growth ModelFirst component is the production functiontells us how the productive resources of the economy can be used to produce and determine the level of outputCobb-Douglas production function9Standard Growth ModelParameters of the modelE is the efficiency of labora higher lev

8、el of E means that more output per worker can be produced for each possible value of the capital stock per worker measures how fast diminishing marginal returns to investment set in10Standard Growth Model01a level of near zero means that the extra amount of output made possible by each additional un

9、it of capital declines very quickly as the capital stock increases11Figure 4.1 - The Cobb-Douglas Production Function for Parameter Near Zero12Standard Growth Model0s/(n+g+)the capital-output ratio will be shrinkingIf ts/(n+g+)the capital-output ratio will be growing41Figure 4.12 - Growth of the Cap

10、ital-Output Ratio as a Function of the Level of the Capital-Output Ratio42Steady-State Growth EquilibriumIf t=s/(n+g+)the growth rate of the capital-output ratio will be zerothe capital-output ratio will be stable (neither shrinking nor growing)*=s/(n+g+) is the equilibrium level of the capital-outp

11、ut ratio43Figure 4.13 - Convergence of the Capital-Output Ratio to Its Steady-State Value44Steady-State Growth EquilibriumWhen the capital-output ratio (t) is at its steady state value (*)output per worker g(yt) is growing at proportional rate gcapital stock per worker is growing at the same proport

12、ional rate gthe economy wide capital stock is growing at the proportional rate n+greal GDP is also growing at proportional rate n+g45Steady-State Growth PathWhen the capital-output ratio is at its equilibrium value (*), the economy is on its steady-state growth pathFrom Chapter 3, we know that as lo

13、ng as we are on the steady-state growth path46Figure 4.14 - Calculating Steady-StateOutput per Worker along theSteady-State Growth Path47Steady-State Growth PathAn increase in the capital-output ratio increases the capital stock directly and indirectlyextra output generated by new capital is source

14、for additional saving and investmentThis leads to a multiplier effect of anything that raises *48Figure 4.16 - The Growth Multiplier: The Effect of Increasing the Capital-Output Ratio on the Steady-State Output per Worker49Steady-State Growth PathLet the growth multiplier () equal /1- Output per wor

15、ker along the steady-state growth path will be50Steady-State Growth PathTo calculate output per worker when the economy is on its steady-state growth pathcalculate the steady-state capital-output ratio *=s/(n+g+)amplify the steady-state capital-output ratio (*) by the growth multiplier =/(1- )multip

16、ly by the current value of the efficiency of labor (Et)51Figure 4.15 - Output per Worker on the Steady-State Growth Path52Reaching the Steady-State Growth PathHow long does it take for the capital-output ratio to adjust to its steady-state value (*)?an economy that is not on its steady-state growth

17、path will close a fraction (1- )(n+g+) of the gap between the steady state value (*) and its current value (t) in a year53Figure 4.17 - West German Convergence to Its Steady-State Growth Path54Labor Force GrowthThe faster the growth of the labor force, the lower will be the economys steady-state cap

18、ital-output ratiothe larger the share of current investment that must go to equip new workers with the capital they needA sudden, permanent increase in labor force growth will lower output per worker on the steady-state growth path55Figure 4.18 - Labor Force Growth andGDP-per-Worker Levels56Figure 4

19、.19 - Effects of a Rise in Population Growth on the Economys Growth Path57Increases in the Depreciation RateThe higher the depreciation rate, the lower will be the economys steady-state capital-output ratioexisting capital stock wears out and must be replaced more quicklyAn increase in the depreciat

20、ion rate will lower output per worker on the steady-state growth path58Productivity GrowthThe faster the growth rate of productivity, the lower will be the economys steady-state capital-output ratiopast investment will be small relative to current outputAn increase in productivity growth will raise

21、output per worker along the steady-state growth path59Increases in the Saving RateThe higher the share of real GDP devoted to saving and investment, the higher will be the economys steady-state capital-output ratiomore investment increases the amount of new capitalA higher saving rate also increases output per worker along the steady-state growth path60Figure 4.20 - National Investment Shares and GDP-per-Worker Levels61Chapter SummaryOne principal force driving long-run growth in o