Growth, Capital Shares, and A New Production Function

摘要提案编号：0242000机构：加州大学伯克利分校；项目：经济学；主要研究者：琼斯，查尔斯。提案题目：增长、资本份额和一个新的生产函数。四个程化的事实，放在一起，构成了现代增长理论中的一个谜题。(1)一些国家可以在很长一段时间内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，要素支付占GDP的份额并不是随时间而恒定的，并且通常在几十年内表现出很大的趋势；(3)对资本和劳动力之间替代弹性的估计往往小于1；(4)资本设备的价格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中，这种现象通常被称为投资特定技术变化。新古典增长模型要表现出稳定状态，要么技术变化在长期内必须完全是劳动力增加，要么生产函数必须是柯布-道格拉斯函数。在存在投资特定技术变化的情况下，为了实现稳定增长，生产函数应为柯布-道格拉斯函数；然而，这与事实2和3不一致。本研究由三个项目组成，这些项目记录并解决了这个难题。第一个项目将在尽可能长的时间内建立一个关于大量国家的资本和劳动力要素支付的新数据集，包括总量和行业层面。这一点很重要，因为事实2与传统观点背道而驰：人们普遍认为资本份额在一段时间内相对稳定。第二个项目提出了一个新的生产函数，它与所有四个风格化的事实一致。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，对稳态增长的要求涉及到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。导致要素定价的短期替代弹性小于1。从长期来看，会出现额外的替代可能性，生产会以柯布-道格拉斯结构发生。第三个项目探讨了这个新生产函数的微观基础。替代弹性低的生产技术可能适合于某一特定的投入组合。要用一种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。给定技术的形态决定了短期替代弹性，而长期替代弹性则由新发现技术的分布决定。稳定增长的一个必要条件是新技术按帕累托分布分布。这个相同的分配假设产生了一个长期生产函数，采用柯布-道格拉斯形式。这项研究将解决增长理论中一些紧迫的难题，这些难题似乎与观察到的事实不一致。

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.