创新补偿性与内生增长可持续性理论研究

近年全球经济的发展趋势引发了对内生增长的平衡增长路径的稳定性和可持续性问题的思考。本文建立三部门一致增长模型,研究近代世界经济发展的阶段性规律。研究表明:内生增长经济均衡有潜在的不稳定性,存在多重均衡的可能;当资源约束限制总生产保持长期常规模回报水平时,只有当知识生产部门的增规模回报率充分大,足以抵消工业生产部门的规模报酬减少的影响,总体经济才能获得可持续发展。为实现正的内生增长,知识生产部门的增规模回报的强度与物质资本在知识生产中的弹性贡献率呈正相关关系。文章提出了不同的长期经济发展的三阶段解释,可以一致地解释近现代长期经济发展主要阶段的动态发展规律。     

教育、创新与经济增长

由于知识的非竞争性,基于R&D的内生增长模型存在规模效应,即人口数量越大,从事R&D的人员越多,经济增长率越快。本文将R&D人员创新活动的有效时间引入知识的积累方程———“点子”生产函数,发现OECD国家科学家和工程师数量增加伴随着R&D人员创新活动的有效时间的减少,二者相互抵消,使得TFP增长率保持不变。通过校准理论模型,本文模拟了49个国家的经济增长率,发现模型对经济增长率跨国数据的解释能力明显强于Lucas模型和Romer模型。如果利用模型对跨国经济增长率的模拟值与真实值之间的残差平方和来评判模型的优劣,则本文模型对Lucas模型和Romer模型至少分别改进了20%和59%。     

江西省总量生产函数与全要素生产率估算:1952-2007

根据索洛余值法和C-D生产函数,建立了江西省总量生产函数模型,并利用江西省1952-2007年相关指标数据进行了测算。研究发现,江西省总量生产函数是一个规模报酬递减的生产函数,江西省经济增长模式为投资驱动型的粗放型经济增长模式,代表技术进步的全要素生产率对江西省经济增长的贡献率长期在20%左右。因此,要提高江西省的全要素生产率贡献率,必须把技术进步放在江西经济社会发展的优先战略地位。     

不确定性下公共安全的经济学分析

本文把公共安全水平纳入效用函数和生产函数,由此建立了一个随机内生经济增长模型。以随机动态最优化作为基本工具,确定了均衡状态下经济均衡增长率、个人消费与财富比以及资本和债券份额。同时,还分析了经济均衡时随机扰动和个人公共安全参与度对经济增长和社会福利的影响。     

不确定性下公共安全的经济学分析

本文把公共安全水平纳入效用函数和生产函数,由此建立了一个随机内生经济增长模型.以随机动态最优化作为基本工具,确定了均衡状态下经济均衡增长率、个人消费与财富比以及资本和债券份额.同时,还分析了经济均衡时随机扰动和个人公共安全参与度对经济增长和社会福利的影响.     

我国知识生产投入产出关系的动态分析

知识生产和创新是促进技术进步和经济增长的重要因素。企业通过R&D投入可以生产出新知识,知识积累形成知识存量,知识存量又推动了技术进步,并进一步引致经济增长。基于新增长理论关于知识生产函数的基本设定,本文首先给出了一个扩张形式的知识生产函数,而后根据我国现实经济数据,在向量自回归的框架下通过脉冲响应函数和方差分解考察了各类因素对我国知识生产的影响。研究表明,R&D经费、R&D人员和知识存量对我国知识生产具有显著的促进作用;外商直接投资和进口对我国知识生产的促进作用不显著。本文认为,应采取切实措施鼓励企业增加R&D投入,同时增加政府财政支出中R&D投入的力度。     

干中学、过度投资和R&D对人力资本积累的“侵蚀效应”

R&D的过度投资对人力资本积累具有"侵蚀效应"。本文提出了一个同时内生化技术进步和人力资本积累的经济增长模型,强调了R&D过程中的两种特征,即R&D过程需要人力资本投入和新技术的研发通过干中学获得,并就R&D对人力资本积累的"侵蚀效应"所造成的负外部性进行了分析。通过比较分散经济均衡和集中经济均衡,本文得出结论:垄断加价及其引致的物质资本和人力资本的过度投资与"侵蚀效应"相互交错、共同作用,会在一定程度上降低人力资本的积累率和经济增长率。     

试论创新、淡化知识产权与经济的持续增长

在索洛(Solow)和斯旺(Swan)的新古典经济增长理论中,均衡的人均经济增长率取决于外生的技术进步。其核心结论是,在缺乏连续技术进步的情况下,人均增长率将最终停止。当然,这一结论是建立在资本的报酬递减规律前提下的。放弃了规模收益递减假设的内生增长理论认为:技术进步既是经济增长之源。又是“知识”内生积累的结果--研究与开发导致了某些专业化投入品的出现,后者对生产效率的改善和外部效应抵消了规模收益的递减。大量的经验研究显示,后进国家确实可以从发达国家技术扩散中得到好处,从而提高本国增长速度。     

湖北省R&D投入对经济增长贡献的实证研究

本文采用科布-道格拉斯生产函数模型,对1997-2011年间湖北省要素投入对经济增长的贡献进行了计量分析,并对资本、劳动和R&D投入对经济增长的贡献率进行了测算。结果发现,资本投入对经济增长的贡献度超过50%,是湖北省经济增长的主要驱动力。1997-2011年间,R&D存量对于经济增长的贡献率为26.09%,湖北省R&D投入对GDP增长的贡献率表现出一定的波动性。本文最后提出:决策者应该加大R&D的投入,并注重R&D结构的合理性,特别是对基础研究的投入。     

环境与经济增长的动态均衡分析

本文以Solow增长模型为基础,在生产函数中引入环境资本这一生产要素,建立了环境Solow模型。它首先分析了资本均衡点和环境资源均衡点的存在性,而后应用非线性微分方程组的相位图分析方法对密集形式模型中的资本存量变化率和环境资本存量变化率进行动态均衡分析,得到在模型设定的条件下,经济达到均衡增长路径的条件。本文同时分析了模型中的参数对过渡期和长期经济增长的影响,并利用脉冲响应函数对结论进行了实证检验。     

Forecasting the price of gold

This article seeks to evaluate the appropriateness of a variety of existing forecasting techniques (17 methods) at providing accurate and statistically significant forecasts for gold price. We report the results from the nine most competitive techniques. Special consideration is given to the ability of these techniques to provide forecasts which outperforms the random walk (RW) as we noticed that certain multivariate models (which included prices of silver, platinum, palladium and rhodium, besides gold) were also unable to outperform the RW in this case. Interestingly, the results show that none of the forecasting techniques are able to outperform the RW at horizons of 1 and 9 steps ahead, and on average, the exponential smoothing model is seen providing the best forecasts in terms of the lowest root mean squared error over the 24-month forecasting horizons. Moreover, we find that the univariate models used in this article are able to outperform the Bayesian autoregression and Bayesian vector autoregressive models, with exponential smoothing reporting statistically significant results in comparison with the former models, and classical autoregressive and the vector autoregressive models in most cases.     

Planned adaptation in risk regulation: An initial survey of US environmental, health, and safety regulation

In principle, we want regulatory programs to be based on current realities, as reflected for example in the best knowledge of relevant experts. That would imply that old rules now on the books should be consistent with today's knowledge base, not just what was known when a rule or standard was originally set. This paper reports on a survey of US programs, examining how often existing rules are actually updated in light of better knowledge, and identifies five programs that attempt to make policy routinely adaptive. These programs exhibit what we term Planned Adaptation: they both revise rules when relevant new knowledge appears, and take steps to produce such improved knowledge. While Planned Adaptation is rare, it is used in several nationally prominent programs, including air pollution, airplane safety, and drug safety. Planned Adaptation is a policy tool that deserves more attention.     

Pleasure and belief in Hume's Decision Process

Abstract

The purpose of this paper is to introduce explicitly pleasure and belief in what aims at being a Humean theory of decision, like the one developed in Diaye and Lapidus (2005a). Although we support the idea that Hume was in some way a hedonist – evidently different from Bentham's or Jevons' way – we lay emphasis less on continuity than on the specific kind of hedonism encountered in Hume's writings (chiefly the Treatise, the second Enquiry, the Dissertation, or some of his Essays). Such hedonism clearly contrasts to its standard modern inheritance, expressed by the relation between preferences and utility.

The reason for such a difference with the usual approach lies in the mental process that Hume puts to the fore in order to explain the way pleasure determines desires and volition. Whereas pleasure is primarily, in Hume's words, an impression of sensation, it takes place in the birth of passions as reflecting an idea of pleasure, whose “force and vivacity” is precisely a “belief”, transferred to the direct passions of desire or volition that come immediately before action. As a result, from a Humean point of view, “belief” deals with decision under risk or uncertainty, as well as with intertemporal decision and indiscrimination problems.

The latter are explored within a formal framework, and it is shown that the relation of pleasure is transformed by belief into a non-empty class of relations of desire, among which at least one is a preorder.     

The greenhouse effect: Damages,costs and abatement

The buildup of so-called greenhouse gases in the atmosphere — CO₂ in particular-appears to be having an adverse impact on the global climate. This paper briefly reviews current expectations with regard to physical and biological effects, their potential costs to society, and likely costs of abatement. For a worst case scenario it is impossible to assess, in economic terms, the full range of possible non-linear synergistic effects. In the most favorable (although not necessarily likely) case (of slow-paced climate change), however, it seems likely that the impacts are within the affordable range, at least in the industrialized countries of the world. In the third world the notion of affordability is of doubtful relevance, making the problem of quantitative evaluation almost impossible. We tentatively assess the lower limit of quantifiable climate-induced damages at $30 to $35 per ton of CO₂ equivalent, worldwide, with the major damages being concentrated in regions most adversely affected by sea-level rise. The non-quantifiable environmental damages are also significant and should by no means be disregarded.The costs and benefits of (1) reducing CFC use and (2) reducing fossil fuel consumption, as a means of abatement, are considered in some detail. This strategy has remarkably high indirect benefits in terms of reduced air pollution damage and even direct cost savings to consumers. The indirect benefits of reduced air pollution and its associated health and environmental effects from fossil-fuel combustion in the industrialized countries range from $20 to $60 per ton of CO₂ eliminated. In addition, there is good evidence that modest (e.g. 25%) reductions in CO₂ emissions may be achievable by the U.S. (and, by implication, for other countries) by a combination of increased energy efficiency and restructuring that would permit simultaneous direct economic benefits (savings) to energy consumers of the order of $50 per ton of CO₂ saved. A higher level of overall emissions reduction — possibly approaching 50% — could probably be achieved, at little or not net cost, by taking advantage of these savings.We suggest the use of taxes on fossil fuel extraction (or a carbon tax) as a reasonable way of inducing the structural changes that would be required to achieve significant reduction in energy use and CO₂ emissions. To minimize the economic burden (and create a political constituency in support of the approach) we suggest the substitution of resource-based taxes in general for other types of taxes (on labor, income, real estate, or trade) that are now the main sources of government revenue. While it is conceded that it would be difficult to calculate the optimal tax on extractive resources, we do not think this is a necessary prerequisite to policy-making. In fact, we note that the existing tax system has never been optimized according to theoretical principles, and is far from optimal by any reasonable criteria.During the academic year 1989–90 Dr. Ayres was at the International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.During the summer of 1989 Mr. Walter was a member of the Young Scientists' Summer Program at IIASA.     

Globalization,Neoliberalism and the attack on social security

Neoliberal political movements advocate privatization of public pension systems. Globalization imposes pressure on nations to conform to neoliberal policy views with respect to the design and structure of social insurance, including public pension systems. The paper begins with an investigation of the economic, ethical and ideological dimensions of the privatization debates in the U.S.; it argues that privatization advocates may be largely moved by ideology, since the other reasons advanced appear weak or unfounded. The second part discusses the history of Social Security, the purposes for its creation, and some of its economic effects. Differences between public and private pension systems are considered. A brief international comparison of some aspects of public pension system finance and benefit structures is presented. The final section considers the ethical, macroeconomic and distributional implications of privatization, prefunding and payroll tax funding, and argues for a pay as you go system financed with income taxes. In order to promote equity, economic security, community, and social cohesion, public pension systems should be universal in coverage. In order to reduce the inequality, income insecurity, and aged poverty generated by market economies, public pension systems ought to be progressive: benefit/contribution ratios should be inversely proportional to income, and progressive income taxes should finance the system. To promote economic growth, the systems should be financed on a pay-as-you-go basis, and should not be prefunded except for an emergency reserve. The fiscal policy recommendations partially depend upon the theory developed by Abba Lerner in the 1940s, and recently advanced by Wynne Godley and Randy Wray: Lerner's “principle of functional finance.”     

SCIENCE AND INDUSTRY: TRACING THE FLOW OF BASIC RESEARCH THROUGH MANUFACTURING AND TRADE

This paper describes flows of basic research through the US economy during the late 20th century. In addition, the paper studies the effect of the flows on scientific papers in industries and fields. This article differs from others in its use of measures of science rather than technology. Together, its results present a picture of the structure of basic research flows in a modern, science-intensive economy. Basic research flows are large within petrochemicals and drugs, and within software and communications. Flows of chemistry, physics, and engineering are common throughout all industries – biology and medicine are almost confined to petrochemicals and drugs; and computer science is nearly as restricted to software and communications. In general, basic research flows are more concentrated within scientific fields than within industries. Our findings concerning the production of scientific papers indicate that the effect of a 1% change in academic R&D spillovers significantly exceeds that of industrial spillovers. In addition, within-field effects exceed effects between-fields, while within- and between-industry effects are roughly equal. It follows that scientific fields limit basic research flows more than industries do, perhaps because large firms implicitly span a range of industries.     

Valuing Mangrove-Fishery Linkages – A Case Study of Campeche, Mexico

This paper explores the value of mangrove systems as a breeding and nursery habitat for off-shore fisheries, focusing on mangrove-shrimp production linkages in Campeche State, Mexico. We develop an open access fishery model to account explicitly for the effect of mangrove area on carrying capacity and thus production. From the long-run equilibrium conditions of the model we are able to establish the key parameters determining the comparative static effects of a change in mangrove area on this equilibrium. We then estimate empirically the effects of changes in mangrove area in the Laguna de Terminos on the production and value of shrimp harvests in Campeche over 1980–90. Our findings suggest that mangroves are an important and essential input into the Campeche shrimp fishery, but that the low levels of deforestation between 1980 and 1990 mean that the resulting losses to the shrimp fishery are still comparatively small. Over-exploitation of the fishery due to open access conditions remains the more pervasive threat, and without better management any long-run benefits of protecting mangrove habitat are likely to be dissipated.     

Interest on reserves and inflation

The payment of interest on reserves has been a common practice in inflationary economies. This policy may seem paradoxical since it involves returning part of the seigniorage, generated by the inflation process, with the intention to finance the fiscal deficit. This paper argues that the motivation for this policy can be captured by the discretionary regime, where the policymaker pays interest on reserves because he is concerned with the erosion of real liquidity by inflation, which is in part beyond his control. However, this policy is an unlikely outcome in the commitment regime, where the policymaker is in full control of inflation.     

An Economic Analysis and Simulation of Woodfuel Management in the Sahel

This paper presents an economic framework and a computationalmethodology for assessing the evolution of woodfuel supply costsand the spatial distribution of biomass in a Sahelian woodlandsetting. Spatial data on standing stock and the costs oftransport to market are used to construct a supply curve for fuelto a fuel-consuming location. Given an exogenously specifieddemand, the model simulates, period by period, the extraction,regeneration, and transport of wood fuels. The model is appliedto evaluate the benefits and ecological impacts of scenarios forwoodland management around the city of N'Djamena, Chad.