《曼昆宏观经济学》PPT课件.ppt

,9 THE REAL ECONOMY IN THE LONG RUN 长期中的实际经济,Production and Growth 生产与增长,Chapter 25,Production and Growth 生产与增长,A countrys standard of living depends on its ability to produce goods and services. 一国的生活水平决定于它生产物品与劳务的能力。,Within a country there are large changes in the standard of living over time. 即使在一个国家内，生活水平也随着时间推移而发生了巨大变化。,一个英国普通家庭及其所有财产，发达国家,人均GDP ： $35,580 预期寿命： 79 岁 成人识字率： 99%,一个墨西哥普通家庭及其所有财产，中等收入国家,人均GDP ： $11,410 预期寿命： 76 岁 成人识字率： 92%,一个马里普通家庭及其所有财产，发展中国家,人均GDP ： $1,130 预期寿命： 50 岁 成人识字率： 46%,Huge effects from tiny differences,1,081.4%,243.7%,85.4%,624.5%,169.2%,64.0%,2.5%,2.0%,100 years,50 years,25 years,The lessons of growth theory,can make a positive difference in the lives of hundreds of millions of people.,These lessons help us understand why poor countries are poor design policies that can help them grow learn how our own growth rate is affected by shocks and our governments policies,Production and Growth,Productivity refers to the amount of goods and services produced for each hour of a workers time. A nations standard of living is determined by the productivity of its workers.,生产率 是指一个工人一小时生产的物品与劳务量。 一国的生活水平决定于它的工人的生产率。,公元5001500年，经济年增长率0.1，产出大约增长3倍。而18世纪英国却取得了10倍于过去的经济增长率；,表1. 不同的增长经历,Copyright2004 South-Western,国别 时期 期初人均GDP 期末人均GDP 增长率（每年）,日本 18902000 1 256美元 26 460美元 2.81 巴西 19002000 650 7 320 2.45 墨西哥 19002000 968 8 810 2.23 加拿大 18702000 1 984 27 330 2.04 德国 18702000 1 825 25 010 2.03 中国 19002000 598 3 940 1.90 阿根廷 19002000 1 915 12 090 1.86 美国 18702000 3 347 34 260 1.81 印度 19002000 564 2 390 1.45 印度尼西亚 19002000 743 2 840 1.35 英国 18702000 4 107 23 550 1.35 巴基斯坦 19002000 616 1 960 1.16 孟加拉国 19002000 520 1 652 1.16,How Productivity Is Determined 生产率是如何决定的,The inputs used to produce goods and services are called the factors of production. 用于生产物品与劳务的投入被称为生产要素 The factors of production directly determine productivity. 生产要素直接决定了生产率。,How Productivity Is Determined 生产率是如何决定的,The Factors of Production 生产要素 Physical capital 物质资本 Human capital 人力资本 Natural resources 自然资源 Technological knowledge 技术知识,How Productivity Is Determined,Physical Capital is a produced factor of production. It is an input into the production process that in the past was an output from the production process. is the stock of equipment and structures that are used to produce goods and services. Tools used to build or repair automobiles. Tools used to build furniture. Office buildings, schools, etc.,物质资本 是生产出来的生产要素。 它是生产过程的投入，也是过去生产过程的产出。 是用于生产物品与劳务的设备与建筑物的存量。 用于生产或修理汽车的工具。 用于生产家具的工具。 办公楼，学校等等,How Productivity Is Determined,Human Capital the economists term for the knowledge and skills that workers acquire through education, training, and experience Like physical capital, human capital raises a nations ability to produce goods and services.,人力资本 经济学家用来指工人通过教育、培训和经验而获得的知识和技能的一个术语。 和物质资本一样，人力资本提高一个国家生产物品与劳务的能力。,How Productivity Is Determined,Natural Resources inputs used in production that are provided by nature, such as land, rivers, and mineral deposits. Renewable resources include trees and forests. Nonrenewable resources include petroleum and coal. can be important but are not necessary for an economy to be highly productive in producing goods and services.,自然资源 由自然界提供的用于生产物品与劳务的投入，如土地、河流和矿藏。 可再生资源包括树木和森林。 不可再生资源包括石油和煤炭。 可能是重要的，但它们并不是一个经济体生产物品与劳务中生产率高的必要条件。,How Productivity Is Determined,Technological Knowledge societys understanding of the best ways to produce goods and services. Human capital refers to the resources expended transmitting this understanding to the labor force.,技术知识 社会对生产物品与劳务的最好方法的理解。 人力资本是指把这些理解传递给劳动力的资源消耗。,经济增长的几个问题,穷国比富国有更快的增长速度？ 储蓄对一个国家的经济增长重要 吗？ 人口如何影响经济增长？ 技术进步对经济增长至关重要吗？,增长理论的三大浪潮,哈罗德多马模型（1946-1948） 核心：发展问题就是增加用于投资的资源 缺陷：资本与劳动零替换；资本产出比率和资本劳动比率被假定是常量，导致，刀锋增长 索洛新古典增长模型 罗默内生增长模型,生产函数,Y = A F(L, K, H, N) Y = 产出量 A = 可得到的生产技术 L = 劳动量 K = 物质资本量 H = 人力资本量 N = 自然资源量 F( ) 是一个表示投入如何结合起来以生产 产出的函数。,The Production Function 生产函数,A production function has constant returns to scale if, for any positive number x, 如果给定任何一个正数x，下式成立，则该生产函数的规模收益不变。 xY = A F(xL, xK, xH, xN) That is, a doubling of all inputs causes the amount of output to double as well. 这就是说，投入翻番就会使产出翻番。,生产函数,规模收益不变的生产函数有一个令人感兴趣的含义。 设 x = 1/L, Y/ L = A F(1, K/ L, H/ L, N/ L) 这里: Y/L = 每个工人的产量 K/L = 每个工人的物质资本 H/L = 每个工人的人力资本 N/L = 每个工人的自然资源,The production function,In aggregate terms: Y = F (K, L ) Define: y = Y/L = output per worker k = K/L = capital per worker Assume constant returns to scale: zY = F (zK, zL ) for any z 0 Pick z = 1/L. Then Y/L = F (K/L , 1) y = F (k, 1) y = f(k) where f(k) = F (k, 1),生产与增长,23,生产函数与与收益递减,当经济的资本水平低时，增加的一单位资本引起产量大幅度增加,当经济的资本水平高时，增加的一单位资本引起产量小幅度增加,生产与增长,24,开始时贫穷的国家倾向于比开始时富裕的国家增长更快的特征。,追赶效应：,The national income identity,Y = C + I (remember, no G ) In “per worker” terms: y = c + i where c = C/L and i = I/L,The consumption function,s = the saving rate, the fraction of income that is saved (s is an exogenous parameter) Note: s is the only lowercase variable that is not equal to its uppercase version divided by L Consumption function: c = (1s)y (per worker),Saving and investment,saving (per worker) = y c = y (1s)y = sy National income identity is y = c + i Rearrange to get: i = y c = sy (investment = saving, like in chap. 3!) Using the results above, i = sy = sf(k),Output, consumption, and investment,Depreciation, = the rate of depreciation = the fraction of the capital stock that wears out each period,Capital accumulation,The basic idea: Investment makes the capital stock bigger, depreciation makes it smaller.,Capital accumulation,Change in capital stock = investment depreciation k = i k Since i = sf(k) , this becomes:,k = s f(k) k,The steady state,If investment is just enough to cover depreciation sf(k) = k , then capital per worker will remain constant: k = 0. This constant value, denoted k*, is called the steady state capital stock.,k = s f(k) k,The steady state,Moving toward the steady state,k = sf(k) k,Moving toward the steady state,k = sf(k) k,k3,Summary: As long as k k*, investment will exceed depreciation, and k will continue to grow toward k*.,An increase in the saving rate,An increase in the saving rate raises investment,causing the capital stock to grow toward a new steady state:,International Evidence on Investment Rates and Income per Person,Population Growth,Assume that the population-and labor force- grow at rate n. (n is exogenous),EX: Suppose L = 1000 in year 1 and the population is growing at 2%/year (n = 0.02). Then L = n L = 0.02 1000 = 20, so L = 1020 in year 2.,Break-even investment,( + n)k = break-even（得失相当的） investment, the amount of investment necessary to keep k constant. Break-even investment includes: k to replace capital as it wears out n k to equip new workers with capital (otherwise, k would fall as the existing capital stock would be spread more thinly over a larger population of workers),The equation of motion for k,With population growth, the equation of motion for k is k = s f(k) ( + n) k,The Solow Model diagram,k = s f(k) ( +n)k,The impact of population growth,Investment, break-even investment,Capital per worker, k,( +n1) k,k1*,An increase in n causes an increase in break-even investment,leading to a lower steady-state level of k.,Prediction:,Higher n lower k*. And since y = f(k) , lower k* lower y* . Thus, the Solow model predicts that countries with higher population growth rates will have lower levels of capital and income per worker in the long run.,International Evidence on Population Growth and Income per Person,一、技术进步和增长率,1.1 技术进步和生产函数 改写为：总生产函数 Y = F(K, AN) 其中，AN为有效工人数量，技术A体现为劳动增强性技术进步（Labor-augmenting technological progress）。 一定资本存量下，同样的产出水平时，技术水平越高，所需要的工人数量越低； 技术进步将增加有效工人数量，进而提升产出水平。,slide 46,Tech. progress in the Solow model,A new variable: E = labor efficiency Assume: Technological progress is labor-augmenting: it increases labor efficiency at the exogenous rate g:,一、技术进步和增长率,1.1 技术进步和生产函数（续） Y/AN = F(K/AN, 1) （规模报酬不变假设） 可写为Y/AN = f(K/AN) (假设f(K/AN) = F(K/AN, 1) 稳态时，单位有效工人资本量（K/AN）和单位有效工人产出（Y/AN）保持不变。,一、技术进步和增长率,单位有效工人资本量（K/AN）的增加，将导致单位有效工人产出（Y/AN）的增加，但增加率呈递减趋势。,一、技术进步和增长率,1.2 产出和资本的相互作用 单位有效工人资本量（K/AN）的增加，将导致单位有效工人产出（Y/AN）的增加，但增幅呈递减趋势。 I/AN = sY/AN = sf(K/AN) gN人口增长率（工人人数增长率）； gA技术进步率； gA +gN有效工人增长率。 要维持一定的单位有效工人资本量（K/AN）,投资水平必须要满足： K +(gA +gN)K。 因此，必要投资量 I/AN = ( +gA +gN )K/AN,一、技术进步和增长率,slide 51,Tech. progress in the Solow model,We now write the production function as:,where L A = the number of effective workers. Hence, increases in labor efficiency have the same effect on output as increases in the labor force.,slide 52,Steady-State Growth Rates in the Solow Model with Tech. Progress,n + g,Y = y AL,Total output,g,(Y/ L ) = y A,Output per worker,0,y = Y/ (L A),Output per effective worker,0,k = K/ (L A),Capital per effective worker,Diminishing Returns and the Catch-Up Effect,As the stock of capital rises, the extra output produced from an additional unit of capital falls; this property is called diminishing returns. Because of diminishing returns, an increase in the saving rate leads to higher growth only for a while.,随着资本存量的增加，从增加的一个单位资本中生产额外产量减少。这种特性被称为收益递减。 因为收益递减，储蓄率增加所引起的更高的增长只是暂时的。,Diminishing Returns and the Catch-Up Effect 收益递减与追赶效应,In the long run, the higher saving rate leads to a higher level of productivity and income, but not to higher growth in these areas. 在长期中，高储蓄率引起高水平的生产率和收入，但在这些变量中并没有高增长。,The catch-up effect refers to the condition that, other things being equal, it is easier for a country to grow fast if it starts out relatively poor. 追赶效应是指在其他条件相同的情况下，如果一国开始时较穷，它要迅速增长是容易的。,The steady state,Education 教育,An educated person might generate new ideas about how best to produce goods and services, which in turn, might enter societys pool of knowledge and provide an external benefit to others. 一个受过教育的人会产生一些有关如何最好地生产物品与劳务的新思想，这些新思想进入社会知识宝库，并给他人带来外部效益。,Property Rights and Political Stability,Property rights refer to the ability of people to exercise authority over the resources they own. An economy-wide respect for property rights is an important prerequisite for the price system to work. It is necessary for investors to feel that their investments are secure.,产权是指人们对其拥有的资源行使权力的能力。 价格制度发生作用的一个重要前提是经济中广泛尊重产权。 让投资者感到他们的投资安全是必要的。,Research and Development,The advance of technological knowledge has led to higher standards of living. Most technological advance comes from private research by firms and individual inventors. Government can encourage the development of new technologies through research grants, tax breaks, and the patent system.,技术知识的进步带来更高的生活水平。 大多数技术进步来自企业和个人所进行的私人研究。 政府通过补贴、减税和专利制度来鼓励新技术的开发。,Population Growth,Population growth interacts with other factors of production: Stretching natural resources Diluting the capital stock Promoting technological progress,人口增长与其他生产要素相互作用: 使自然资源量更加紧张 稀释了资本存量 促进了技术进步,slide 60,我国未来经济增长前景,中国国民经济研究所樊纲观点： 未来15年中国经济增长率将保持在6%至9%之间，而决定经济增速快慢的因素将主要是全要素生产力(TFP)。与投资和人力资本等“内需增长因素”不同，TFP增长因素是指资本及劳动力在使用整合中的有效性，它不需要继续追加投资和劳动力投入，只要继续创新就可以持续下去。必须通过深化改革、解放生产力来促使其加速发展。,slide 61,周天勇：未来十几年中，中国的经济还将会在78的速度间增长，2020年时，按不变价格计算，GDP总量将达到38万亿，人均GDP将达到26000元 中国目前人均GDP的水平还很低，中国未来低基数基础上的高增长是国民经济成长的重要趋势。 中国有着丰富的人力资源，工资成本目前为一些工业化国家的150130，即使2020年实现较为富裕的小康社会，工资成本也还为这些工业化国家的120115,slide 62,从东亚一些国家和地区经济增长的经验来看，结构转型在城市化水平3555，人均GDP在10003000美元阶段，仍然是高速增长阶段。比如韩国在19531962年间GDP增长速度平均为3.84，19621991年间平均增长8.48，19912000年间平均增长5.76，高速增长长达38年；新加坡19601965年间平均增长5.74，19651984年间平均增长9.86，19842000年间平均增长7.18，高速增长了35年；中国台湾地区19511962年平均增长7.92，19621987年平均增长9.48，19872000年平均增长6.59，高速增长长达49年。而中国内地未来结构转型特征和人均GDP水平变动，