复杂科学在生态系统研究中的应用

复杂科学的理论、方法在生态系统的研究应用具有很高的价值.生态系统是一个复杂适应性系统,处于混沌边缘或临界态,内部作用是生态系统复杂化、有序化及自组织的主要推动力.生态系统复杂性是目前生态研究的前沿领域之一.文章介绍了生态系统的复杂性和利用复杂科学的原理和方法来研究进化和生态学问题.生态系统复杂性就是生态系统内不同层次上的结构与功能的多样性,自组织性及有序性.其研究方法主要有元胞自动机法、遗传算法、博弈论、复杂网络等.运用复杂科学的原理和方法,探讨生态系统复杂性的机理及发展规律,为认识和解决生态问题提供一条新的途径.     

企业竞争力的复杂性研究

文章从复杂性的角度对企业竞争力进行了分析,并分别从含义、测度、形成机理、非线性和层次性等方面分析了企业竞争力的复杂性,认为在竞争力研究中引入复杂理论将有助于企业竞争力的理论研究。     

市场过程的复杂性与演化适应特征

作为一个过程的市场,具有复杂演化系统的特征.市场过程理论、复杂性理论的一个共同努力,是试图复兴古典经济思想对复杂现象的理解方法.作为复杂适应系统的市场过程,具有非线性、试错、创造性、路径依赖、自组织和演化特征.复杂市场经济中,面临不可避免无知的人类,只有依靠企业家发现过程才能对付知识问题.     

基于复杂性科学视角的东北老工业基地自主创新研究

东北老工业基地的自主创新是一个由知识、经济、社会等多种因素交互作用的复杂动力过程,是一种复杂性非线性系统。因此复杂性科学的管理理论无疑对东北老工业基地的自主创新具有一定的借鉴意义。文章尝试通过复杂性科学的协同学理论、自组织理论、耗散结构理论和混沌理论,分析东北老工业基地自主创新的内在机理,为东北老工业基地的自主创新活动提供理论依据。     

混沌理论对高校学生管理工作的启示

高校学生管理工作是一项复杂的系统工作,混沌现象在高校学生管理工作中普遍存在.混沌理论作为复杂性科学理论的出现,在物理、数学、管理等领域得到了广泛的应用,学习一定的混沌理论知识,有助于了解和掌握学生管理工作中的规律,丰富工作方法,提高管理效率.本文简要概述了混沌理论,并尝试应用混沌理论对高校学生管理工作以新的启示.     

滑坡灾害评估与治理研究进展

由于滑坡地质灾害本身所具有的复杂性、不确定性、承栽体的易损性等一系列的问题,这些严重阻碍了滑坡灾害评估方法的制定和推广.本文系统的总结了国内外滑坡灾害的一些特点和评估方法,对灾滑坡害评估的一些研究成果进行了总结,分析了今年来滑坡灾害评估方法制定过程中所遇到的一些困难,并提出了相应的一些解决办法.     

中国乡城流动人口社会网络复杂性特征分析

借助社会网络等非正式制度方式实现再社会化是乡城流动人口融入城市生活的主要途径之一。对流动人口社会网络的分析不仅可以揭示其网络结构特点,也将为进一步研究流动人口再社会化过程提供理论基础。采用深圳市流动人口专项调查中的整体网络数据,借助复杂性科学,尤其是复杂网络的研究方法,系统分析了乡城流动人口社会支持网络与讨论网络的复杂性特征。在乡城流动人口社会网络中广泛存在小世界现象和无标度特性等复杂网络特征。复杂性科学可以为分析诸如乡城流动人口这样的复杂系统提供有效方法,也是拓展复杂性科学,尤其是复杂网络应用领域的有益尝试。     

多智能体的知识管理对CAS理论的补充与完善

复杂性理论中的自适应复杂系统(CAS)是知识管理实现的理论基础,复杂性理论发展至今,对知识管理的实际应用起到了很好的推动作用。随着知识管理研究的深入和技术进步,复杂性理论也要得到丰富和充实,使之适应新的理念、新的环境和新的技术。     

基于复杂性理论的产业集群协同进化探究

近期的研究越来越多地运用复杂性理论来解释各种组织形式,如何将复杂性理论运用于产业集群研究是其中的一个前沿问题。文章将产业集群看作为复杂适应系统,运用复杂性理论特别是其中的协同进化原理对产业集群的演化过程进行分析。文章论证了Pouder&St.John(1996)和其他学者所描述的"热点"类型集群在演化过程中的衰落并非不可避免。基于复杂性理论,来探究一个高绩效产业集群的演化过程,用协同进化观点来支持产业集群高绩效的持久性。     

用开放的复杂巨系统理论探讨现代企业管理问题

复杂性科学是上世纪80年代兴起的科学研究新领域,许多研究成果在自然科学、社会科学、管理科学、人文科学等领域得到广泛的应用。本文概述了中国著名科学家钱学森在世界科学前沿领域复杂性研究中的重要成果--开放的复杂巨系统理论及其方法论,并将这一理论用于研究现代企业管理创新的问题,以期抛砖引玉。     

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.