Growth, Capital Shares, and A New Production Function

题目：增长、资本份额和新的生产函数四个风格化的事实合在一起，构成了现代增长理论中的一个谜题：(1)一些国家可以长期以相对稳定的平均速度增长；(2)与传统观点相反，在大多数国家，要素报酬占GDP的比例并不是随着时间的推移而恒定的，通常会呈现出几十年的大趋势，(3)对资本和劳动力之间替代弹性的估计往往小于统一，(4)资本设备相对于消费的价格正在下降，这表明一些技术变化体现在设备资本上，这种现象通常被称为投资专用性技术变化。要使新古典增长模型呈现稳定状态，从长远来看，技术变革必须完全是劳动力增加，或者生产函数必须是柯布-道格拉斯函数。为了在存在投资特定技术变化的情况下获得稳定的增长，生产函数应该是柯布-道格拉斯函数；然而，这与事实2和事实3不一致。本研究由三个项目组成，以记录和解决这一难题。第一个项目将在尽可能长的时间内创建一个关于大量国家在总量和行业层面上对资本和劳动力的要素支付的新数据集。这一点很重要，因为事实2与传统智慧背道而驰：人们普遍认为，资本份额随着时间的推移相对不变。第二个项目提出了一个新的生产函数，它符合所有四个风格化的事实。要素份额和替代弹性的估计是由生产函数的短期性质驱动的。然而，对稳定增长的要求涉及长期生产函数的形状。这里提出的生产函数利用了这种差异。要素定价的短期替代弹性小于1。从长远来看，出现了更多的替代可能性，并以Cobb-Douglas结构进行生产。第三个项目探索了这一新生产函数的微观基础。一种具有低替代弹性的生产技术可能适合于给定的投入组合。要用非常不同的投入组合进行生产，可能需要一种新的生产技术。一种特定技术的形状决定了替代的短期弹性，而长期替代弹性则由新发现的技术的分布决定。稳定增长的一个必要条件是新技术是按照帕累托分布分布的。同样的分布假设产生了一个采用柯布-道格拉斯形式的长期生产函数。这项研究将解决增长理论中一些似乎与观察到的事实不符的紧迫难题。

ABSTRACTPROPOSAL NUMBER: 0242000INSTITUTION: University of California at BerkeleyNSF PROGRAM: ECONOMICSPRINCIPAL INVESTIGATOR: Jones, Charles IPROPOSAL TITLE: Growth, Capital Shares, and A New Production FunctionFour stylized facts, taken together, constitute a puzzle in modem growth theory: (1) some countries can grow at a relatively stable average rate for a long time, (2) contrary to conventional wisdom, factor payments as a share of GDP are not constant over time in most countries and typically exhibit large trends for several decades, (3) estimates of the elasticity of substitution between capital and labor are often less than unity, (4) the price of capital equipment relative to that of consumption is falling, suggesting that some technical change is embodied in equipment capital, a phenomenon often called investment-specific technical change. For a neoclassical growth model to exhibit a steady state, either technical change must be entirely labor augmenting in the long run, or the production function must be Cobb-Douglas. To get steady growth in the presence investment-specific technical change, the production function should be Cobb-Douglas; however, this is inconsistent with Facts 2 and 3. This research consists of three projects that document and resolve this puzzle. The first project will create a new dataset on factor payments to capital and labor for a large number of countries, both at the aggregate and industry levels, over as long a time as possible. This is important because Fact 2 runs counter to the conventional wisdom: it is commonly accepted that capital shares are relatively constant over time. The second project proposes a new production function that is consistent with all four stylized facts. Factor shares and estimates of the elasticity of substitution are driven by short-run properties of the production function. However, requirements for steady-state growth involve the shape of the long-run production function. The production function proposed here exploits this difference. The short-run elasticity of substitution responsible for factor pricing is less than one. In the long run, additional substitution possibilities arise and production occurs with a Cobb-Douglas structure. The third project explores the microfoundations for this new production function. A production technique, with a low elasticity of substitution, may be appropriate for a given input mix. To produce with a very different input mix, a new production technique may be required. The shape of a given technique governs the short-run elasticity of substition, while the long- run elasticity of substitution is determined by the distribution of newly discovered techniques. A necessary condition for steady growth is that new techniques are distributed according to a Pareto distribution. This same distributional assumption generates a long-run production function that takes the Cobb-Douglas form. This research will resolve some of pressing puzzles in growth theories that seem to be inconsistent with the observed facts.