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.     

Simpler Probabilistic Population Forecasts: Making Scenarios Work

The traditional high-low-medium scenario approach to quantifying uncertainty in population forecasts has been criticized as lacking probabilistic meaning and consistency. This paper shows, under certain assumptions, how appropriately calibrated scenarios can be used to approximate the uncertainty intervals on future population size and age structure obtained with fully stochastic forecasts. As many forecasting organizations already produce scenarios and because dealing with them is familiar territory, the methods presented here offer an attractive intermediate position between probabilistically inconsistent scenario analysis and fully stochastic forecasts.     

Bayesian life test planning for the Weibull distribution with given shape parameter

This paper describes Bayesian methods for life test planning with Type II censored data from a Weibull distribution, when the Weibull shape parameter is given. We use conjugate prior distributions and criteria based on estimating a quantile of interest of the lifetime distribution. One criterion is based on a precision factor for a credibility interval for a distribution quantile and the other is based on the length of the credibility interval. We provide simple closed form expressions for the relationship between the needed number of failures and the precision criteria. Examples are used to illustrate the results.Received: October 2002 / Revised: March 2004     

基于集对分析法的地区大中型工业企业自主创新能力评价

为了对地区大中型工业企业自主创新能力进行全面、科学的评价,基于集对分析法,提出了地区大中型工业企业自主创新能力评价指标体系及综合评价模型。通过对我国30个省市区大中型工业企业的实证分析,表明该方法科学简便,具有很好的实用价值。     

家族企业财务管理问题的理性思考

改革开放以来,我国家族企业在发展过程中面临一系列的机遇,但同时也暴露出一些问题,特别是财务管理的不科学、混乱严重阻碍了家族企业的进一步发展。财务管理是现代家族企业管理的基础和核心,家族企业应当认真分析在财务管理方面的一些问题,强化财务管理的重要性,建立健全财务管理制度与监督控制制度。     

矿渣微粉和磨细粉煤灰双掺混凝土的试验与应用

讨论了矿渣微粉和磨细粉煤灰双掺(简称FS双掺)在大体积混凝土以及高强混凝土中的试验与应用,以此体现了它们在经济上的显著效应。     

关于完善我国部门预算改革的基本思路

文章就如何进一步完善我国部门预算改革问题 ,从完善法规政策、改革预算科目、制定合理标准、调整相应机构等方面提出了一些建议。     

浅析中国传统民居所反映出的家文化偏向

对我国传统民居所反映出的家文化偏向进行了深入系统的分析,并归纳出下面几点结论:传统民居选址、布局的风水模式,反映出了一种家之环境文化偏向;传统民居的对称组群封闭式布局,反映出了一种家之伦常文化偏向;传统民居材质的“当下存在”和祠堂的“永存不灭”,反映出了一种家之“弃祈”文化偏向。     

德日刑法中的遗弃犯罪及对我国刑法的启示——从一则案例谈起

我国刑法中的遗弃罪之本质在于对公民在家庭中受扶养权利的侵犯，行为人和被害人必须是同一家庭的成员。对于司法实践中发生的非家庭成员之间的严重遗弃行为因无明文规定而无法予以惩治，刑法法益保护之机能也就因此不能实现。有必要借鉴德日刑法相关立法，以完善我国刑法中关于遗弃罪的规定。     

国家规模对贸易投资便利化的影响——基于“一带一路”沿线国家数据的实证分析

以"一带一路"53个沿线国家为研究对象测算贸易投资便利化水平，并运用面板数据模型分析国家规模对贸易投资便利化的影响。研究发现：第一，2013年后，"一带一路"沿线国家的贸易投资便利化水平呈上升趋势。第二，在总样本和分时段样本中，国土规模对"一带一路"沿线国家的贸易投资便利化均具有显著的负向影响。第三，在分时段样本中，"一带一路"倡议提出前，居民收入规模是贸易投资便利化的重要影响因素，而倡议的实施使得贸易投资便利化不再受居民收入规模的影响。第四，在分区域样本中，各变量对贸易投资便利化的影响存在较大差异。基于此，本研究从国家规模的角度为"一带一路"沿线国家贸易投资便利化条件的改善以及中国在"一带一路"沿线国家的直接投资和双边贸易提出建议。