教育、人力资本投资与经济增长——广东省和四川省的比较研究

人力资本在社会经济发展中具有基础性、战略性的作用。而教育是人力资本投资,提高人力资本质量的重要途径。本文利用生产函数分析比较广东省和四川省经济增长过程中人力资本投资对经济增长的产出弹性以及贡献率,实证了人力资本是经济增长的重要决定因素,并对教育和经济发展的关系做出较为全面的解释,对四川省的经济发展提出政策建议。     

Robustness issues in multilevel regression analysis

A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood.     

三维激光扫描仪在地形测量中的应用

文章从三维激光扫描仪在测量中的作用入手,详细介绍了三维激光扫描仪的工作原理和三维激光扫描系统,并说明了三维激光扫描仪配套三维数据处理软件的功能,着重介绍了三维数据的处理方法:点云的连接、特征线的提取、对地物的三维建模(TIN建模),在TIN建模中,介绍了狄洛尼三角网的构网方法。     

在铁路货运营销中运用价格策略的探讨

价格是市场营销组合的重要因素。铁路货物运价制度运用得当与否直接关系着吸引运量的多少和使路运输企业利润的高低。并影响着运输市场营销组合的其它因素。根据营销环境的变化，灵活调整价格，科学制定价格策略，才能使企业获得最佳的经济效益。本文通过分析现行运价体系存在的问题，就如何在铁路货运营销活动中运用价格策略进行了探讨。     

在金融全球化下我国金融安全若干问题综述

20世纪80年代以来,金融全球化已成为世界经济发展的一个鲜明特征和基本趋势。在金融危机频繁爆发的今天,如何能够在金融全球化中获利,又能维护国家的金融安全,尤其是象我国这样一个经济转型的国家。本文分别综述了国内外学者对于金融全球化下金融安全问题的研究,包括国外的金融危机理论;又分别从国家经济安全、金融效率、金融风险,资本外逃等方面探讨了与国家金融安全的关系。     

Localized Innovation and Productivity Growth in Asia: An Intertemporal DEA Approach

Recent contributions to growth theory stress the importance of localized innovation for the performance of more backward countries. In earlier papers, analyses by means of DEA techniques confirmed this intuition. In this paper, we extend this type of analysis by relaxing the macroeconomic viewpoint adopted until now. New databases on output, labor and capital input in the agricultural and manufacturing sectors are developed for 40 countries. Using intertemporal DEA, it is found that changes in the global production frontier are localized at high levels of capital intensity. This result is stronger in agriculture than in manufacturing. Further, a decomposition of labor productivity growth in eight Asian countries for the period 1975–1992 into the effects of capital intensification, learning and innovation is made. The results suggest that there is a particular development path in which increases in capital intensity appear to be a prerequisite to benefit from international technology spillovers.JEL Classification: O14, O30, O40, O47     

企业物流系统的经济评价方法探析

文章通过对物流成本概念及其特性和物流成本系统化控制的分析,运用物流活动的经济评价的方法对物流系统的成本进行动态的经济评价,为企业提供物流成本控制与管理依据,以便企业能够及时准确的进行调整更有效更迅速的优化系统,使企业的物流成本大大降低,从而增强企业的竞争力。     

经济增长质量的模糊综合评价模型研究

以经济增长质量为研究对象,试图对经济增长质量进行定量分析。在对经济增长质量进行定性分析的基础上建立了经济增长质量指标体系,运用模糊数学理论和层次分析法建立经济增长质量的多层次模糊评价模型,并利用该模型对我国的经济增长质量进行了实证分析。经实证分析表明:采用多层次模糊评判理论进行经济增长质量综合评价是合理、可行的。     

Preventing HIV in injection drug users: exploring the tradeoffs between interventions

Injection drug users (IDUs) transmit the human immunodeficiency virus (HIV) via both needle sharing and sex. Available interventions for this population have varying costs and effectiveness and focus on different risk behaviors. In this analysis, we look at two interventions. One is inexpensive, broad-based and provides modest risk reductions (street outreach (SO)); the other is narrowly focused, expensive and relatively effective (methadone maintenance). This analysis explores the effects of population risk behavior, intervention effectiveness, intervention costs, and decision constraints when allocating funds between these two interventions to maximize effectiveness. We develop a model of the spread of HIV, dividing IDUs into susceptibles (uninfected) and infectives, and separately portraying sex and injection risk. We simulate the epidemic in New York City for time periods from the mid-1980s to the early 1990s, and incorporate the behavioral effects of two interventions performed singly or in combination to find the allocation that maximizes the number of infections averted in the IDUs and their noninjecting sex partners, assuming interventions have increasing marginal costs. We find that the optimal allocation nearly always involves spending the maximum allowable amount on SO. This result is largely insensitive to variations in risk parameters, intervention efficacy, or cost. The model's structure, however, makes clear that many factors contribute to this insensitivity, namely the scope of the interventions, the dual drug/sex nature of HIV risk in the population, the asymmetry of sexual risk for men and women, and the potential benefits to nonIDUs.     

VE在油田开发中的应用

孤岛采油厂历经30多年的开发,已处于特高含水期产量递减阶段。由于新井产量受到自然资源和投资的限制是有限的,要减缓原油产量的递减,依靠的是大量增产措施的投入,而每项措施的实施需要耗费几万元到几十万元的费用。所以,引起开发后期油田成本上升的主要原因是油田增产措施难度加大,投入相应增加。为此,我们引入VE原理,科学实施增产措施工作量,达到了降低作业成本,提高增油效果的目的。