朝鲜族人口自然增长率下降对发展的影响

本文分析了朝鲜族人口减少的主要原因及负面影响,并提出了解决的对策.     

A Learning Curve Analysis of Expert System Use*

In this article, we study how an expert system affects novice problem solving in a financial risk analysis domain. We demonstrate that novice performance is improved after exposure to an expert system. Further, we show that novice performance continues to improve when the system is withdrawn. By comparing learning curves for people with exposure to those without, we can assess how much the system has benefitted its users. We demonstrate a quantitative methodology to measure the increment of learning due to the use of an information technology. We also explore the issue of how expertise is transferred from the system to the user.     

Integrating Neural Networks and Semi-Markov Processes for Automated Knowledge Acquisition: An Application to Real-time Scheduling*

Recently, artificial neural networks (ANN) have gained attention as a promising modeling tool for building intelligent systems. A number of applications have been reported in areas varying from pattern recognition to bankruptcy prediction. In this paper, we present a creative methodology that integrates computer simulation, semi-Markov optimization, and ANN techniques for automated knowledge acquisition in real-time scheduling. The integrated approach focuses on the synergy between operations research and ANN in eliciting human knowledge, filtering inconsistent data, and building competent models capable of performing at the expert level. The new approach includes three main components. First, computer simulation is used to collect expert decisions. This step allows expert knowledge to be obtained in a non-intrusive way and minimizes the difficulties involved in interviewing experts, constructing repertory grids, or using other similar structures required for manual knowledge acquisition. The data collected from computer simulation are then optimized using a semi-Markov decision model to remove data redundancies, inconsistencies, and errors. Finally, the optimized data are used to build ANN-based expert systems. The integrated approach is evaluated by comparing it with the human expert and using ANN alone in the domain of real-time scheduling. The results indicate that ANN-based systems perform worse than human experts from whom the data were collected, but the integrated approach outperforms human experts and ANN models alone.     

A Comment on Second-Order Polynomial Regression Models

In a recent article, Chatterjee and Greenwood [1] addressed the problem of multicollinearity in polynomial regression models. They noted that there is a high correlation between X and X²; therefore, a second-order polynomial model suffers the consequences of collinearity. Chatterjee and Greenwood [1] suggested a method they believe will overcome the problem. The contention of the present comment is that the suggested method accomplishes nothing and, indeed, has the potential to lead the unwary researcher to the wrong inference and misinterpretation of his results.     

金融周期、金融波动与中国经济增长——基于省际面板门槛模型的研究

本文应用面板门槛模型,研究了2005-2017年间我国31个省（市、自治区）金融波动对经济增长的影响。研究发现,随着金融周期所处阶段的变化,金融波动对经济增长会产生显著的非对称性双重门槛效应,主要体现为如下两点：首先,金融周期处于膨胀期、平稳期和萧条期时金融波动对经济增长会产生负向影响,但从影响系数值的大小来看,处于膨胀期时最大,是后两者的2倍之多,处于平稳期时最小且并不显著;其次,分区域的稳健性检验表明,金融发展水平高的区域双重门槛值出现得早,且两个门槛值间的区间要比金融发展水平低的区域宽28%。这些结论说明,经济增长对于金融波动的容忍弹性会随着金融周期所处的阶段而变化,金融发展水平的提高会放大经济增长对金融波动的容忍区间,但也会加速金融周期处于膨胀期时爆发金融危机的可能性,这使得当前我国存在着进一步发展金融水平和严控金融风险的矛盾,对此本文也提出了相应的政策建议。     

MARKET PENETRATION AND LOCATIONAL CONFLICT IN FRANCHISE SYSTEMS*

This paper addresses the questions of market penetration and locational conflict in a franchise system of distribution. The models developed provide a means to evaluate alternative scenarios and the effects of various franchise policies. It is shown that the market penetration and location goals of the members of a franchise system coincide only under a very limited set of circumstances.     

从霍尔顿的成长经历中还可以读出什么——塞林格《麦田里的守望者》的心理评析

霍尔顿是60年前塞林格在《麦田里的守望者》中塑造的人物形象,在历史潮水的冲刷之下,这个具有鲜明个性的文学形象,历久弥新,并无褪色,以心理学的视角重新分析这个人物的成长经历,会使我们对小说的精神内涵有许多新的发现。     

On high fertility rates in developing countries: birth limits, birth taxes, or education subsidies?

In this paper, we consider two types of population policies observed in practice: birth limits and birth taxes. We find that both achieve very similar equilibrium solutions if tax revenue finances lump-sum transfers. By reducing fertility and promoting growth, both birth policies may achieve higher welfare than conventional education subsidies financed by income taxes. A birth tax for education subsidies can achieve the first-best solution. The welfare gain of the first-best policy may be equivalent to a massive 10–50% rise in income, depending on the degree of human capital externalities and the elasticity of intertemporal substitution.      

教育对经济增长贡献算法的改进

本文就教育对经济增长贡献已有的算法及其缺陷进行评述,考虑到AK模型能够比较好地刻画我国的经济增长以及教育本身的延时性,本文提出两条改进意见:发达地区可采用舒尔茨的教育资本存量法,非发达地区和全国范围宜在此基础上选用延期回归方程法,本文还结合深圳1978~1994和中国1978~1996年的样本对此作出解释和验证.