关键词： 增长极培育   区域合作   计量经济模型  

摘要： 贵州目前处于工业化中期的前端,是增长极极化的阶段,重要任务是培育和壮大增长极。通过区域合作的方式、依托区域资源优势和产业互补性加强合作,是加快培育增长极的有效途径。利用计量经济模型,通过测算贵阳和周边省会城市的场强,量化城市的辐射能力和辐射范围,以此作为选择区域合作方向和重点的判断依据,具有较强的合理性和可操作性。

关键词： Dry land   Forest policy   Matrix model   Model scenarios   Traditional management  

摘要： A deterministic, non-linear dynamic bio-economic model is developed to analyze interactions between goats and forests under different management regimes at a village level in Zagros, Iran. Data for the study were mainly obtained through participatory rural appraisal, village level survey, forest inventory and secondary sources. The model was run under six alternative management regimes represented by model scenarios: (1) BAU: the business as usual, (2) NSIR: no state intervention with traditional rules, (3) NRFG: no state and traditional rules, (4) NRF: no state and traditional rules without goat husbandry, (5) NFH: no forest harvesting, and (6) NGH: no goat husbandry. The results of BAU, NSIR and NRFG scenarios brought out that state control, traditional rules as well as biological feed-back mechanisms keep the goat population within carrying capacity. Comparing forest density in NSIR and NRFG model scenarios showed that even without state control, villagers managed to preserve forest resources through traditional institutional arrangements. The population of goats would decline if forest harvesting was banned due to reduction in coppicing and fodder availability. The highest NPV was observed under the NRFG model scenario resulting in lowest sustainability of resource use. (C) 2014 Elsevier B.V. All rights reserved.

关键词： CGE model   Energy   Environment   Carbon tax  

摘要： We build, calibrate and simulate a stylized energy-economy model designed to evaluate the magnitude of carbon tax that would allow the French economy to reduce by a factor of four its CO2 emissions at a forty-year horizon. We estimate the substitution possibilities between fossil energy and other factors for households and firms. We build two versions of the model, the first with exogenous technical progress, and the second with an endogenization of the direction of technical progress. We show that if the energy-saving technical progress rate remains at its recent historical value, the magnitude of the carbon tax is quite unrealistic. When the direction of technical progress responds endogenously to economic incentives, CO2 emissions can be reduced by more than that allowed by the substitution possibilities, but not by a factor of four. To achieve this, an additional instrument is needed, namely a subsidy to fossil energy-saving research. The redirection of technical progress, which is a driver of energy transition, comes at a small cost in terms of the overall growth rate of the economy.

关键词： Design   Algorithms   Performance   Cloud service   service composition   economic model  

摘要： This article considers cloud service composition from a decision analysis perspective. Traditional QoS-aware composition techniques usually consider the qualities available at the time of the composition because compositions are usually immediately consumed. This is fundamentally different in the cloud environment where the cloud service composition typically lasts for a relatively long period of time. The two most important drivers when composing cloud service are the long-term nature of the composition and the economic motivation for outsourcing tasks to the cloud. We propose an economic model, which we represent as a Bayesian network, to select and compose cloud services. We then leverage influence diagrams to model the cloud service composition. We further extend the traditional influence diagram problem to a hybrid one and adopt an extended Shenoy-Shafer architecture to solve such hybrid influence diagrams that include deterministic chance nodes. In addition, analytical and simulation results are presented to show the performance of the proposed composition approach.

关键词： Decision Support Techniques   Economics, Pharmaceutical   Health Care Sector/economics   Humans   Models, Economic  

摘要： Health economic models have become the primary vehicle for undertaking economic evaluation and are used in various healthcare jurisdictions across the world to inform decisions about the use of new and existing health technologies. Models are required because a single source of evidence, such as a randomised controlled trial, is rarely sufficient to provide all relevant information about the expected costs and health consequences of all competing decision alternatives. Whilst models are used to synthesise all relevant evidence, they also contain assumptions, abstractions and simplifications. By their very nature, all models are therefore 'wrong'. As such, the interpretation of estimates of the cost effectiveness of health technologies requires careful judgements about the degree of confidence that can be placed in the models from which they are drawn. The presence of a single error or inappropriate judgement within a model may lead to inappropriate decisions, an inefficient allocation of healthcare resources and ultimately suboptimal outcomes for patients. This paper sets out a taxonomy of threats to the credibility of health economic models. The taxonomy segregates threats to model credibility into three broad categories: (i) unequivocal errors, (ii) violations, and (iii) matters of judgement;and maps these across the main elements of the model development process. These three categories are defined according to the existence of criteria for judging correctness, the degree of force with which such criteria can be applied, and the means by which these credibility threats can be handled. A range of suggested processes and techniques for avoiding and identifying these threats is put forward with the intention of prospectively improving the credibility of models.

关键词： Exogenous shocks   Pulse functions   Devaney chaos   Period-doubling cascade   Control of chaos  

摘要： We investigate the generation of chaos in economic models through exogenous shocks. The perturbation is formulated as a pulse function where either values or instants of discontinuity are chaotically behaved. We provide a rigorous proof of the existence of chaos in the perturbed model. The analytical results are applied to Kaldor-Kalecki-type models of the aggregate economy subject to export and rainfall shocks, respectively. Simulations are used to demonstrate the emergence and the control of chaos. Our results shed light on a novel source of chaos in economic models and have important implications for policy-making. (C) 2014 Elsevier B.V. All rights reserved.

关键词： 数学生物经济模型   概周期解   Lyapunov函数  

摘要： 通过构造Lyapunov函数研究了一类非自治的数学生物经济模型的概周期解的存在性,得到了保证概周期解存在的充分性判椐.

关键词： 用电量   计量模型   电量计量  

摘要： 采用上海市统计局和上海市电力公司相关统计数据,建立计量经济学模型,利用多种检验对模型进行改进,根据模型结果对2012年上海市用电量进行验证,验证结果表明该模型对今后实际预测具有现实意义。

关键词： 宏观经济学家   DSGE   所有   宏观经济理论  

摘要： NoahSmith曾做了一个关于人们使用何种经济模型进行预测的调查,结论十分有趣。假如你是一名宏观投资者,并且你要做的只是作出无条件的预测,例如预测下个季度的GDP,那么你可以直接使用老式的SEM模型。1因为相关关系是你唯一需要关心的,而因果关系并不重要。但是假如你想对某项政府政策变化对经济的影响作出预测,例如联储的政策放松如何影响经济增长。

关键词： 柔鱼   生物经济模型   多船队   鱿钓渔业   资源优化配置   西北太平洋  

摘要： 西北太平洋柔鱼是中国大陆、日本及中国台湾鱿钓船队共同开发的主要经济头足类之一,如何兼顾鱿钓船队的渔业利益,并综合考虑生态效益、经济效益和社会效益,科学制定渔业管理目标是确保柔鱼资源可持续利用的重要研究内容。根据中国大陆、日本及中国台湾鱿钓船队的渔获统计数据及相关经济参数,构建基于多船队的生物经济模型,模拟了50年内(1997—2047年)各捕捞船队开发柔鱼资源过程中的动态变化,并探讨了在10种不同的管理方案下各船队捕捞努力量、柔鱼资源量、渔获产量及其渔业利润随时间的动态变化。结果表明,在所有设计方案下,随着捕捞努力量的动态变化,资源量在前10a均呈急剧下降趋势,随后经长期波动后逐渐趋于稳定并维持在较低水平。从长期效益来看,方案9(提高中国台湾船队捕捞系数)的累计产量及累计利润中等,但能兼顾各国或地区船队间的经济利益和社会效益,可建议以方案9作为柔鱼渔业的参考管理目标;从柔鱼资源保护角度来看,方案4(提高中国大陆船队作业成本)的资源量保持最好,可以对方案4进行适当的优化作为参考管理目标,即提高中国大陆船队作业成本,同时适当降低日本船队的可捕系数,可确保柔鱼资源量保持在更高的水平上。