Performance of information criteria for spatial models

Model choice is one of the most crucial aspect in any statistical data analysis. It is well known that most models are just an approximation to the true data-generating process but among such model approximations, it is our goal to select the ‘best’ one. Researchers typically consider a finite number of plausible models in statistical applications, and the related statistical inference depends on the chosen model. Hence, model comparison is required to identify the ‘best’ model among several such candidate models. This article considers the problem of model selection for spatial data. The issue of model selection for spatial models has been addressed in the literature by the use of traditional information criteria-based methods, even though such criteria have been developed based on the assumption of independent observations. We evaluate the performance of some of the popular model selection critera via Monte Carlo simulation experiments using small to moderate samples. In particular, we compare the performance of some of the most popular information criteria such as Akaike information criterion (AIC), Bayesian information criterion, and corrected AIC in selecting the true model. The ability of these criteria to select the correct model is evaluated under several scenarios. This comparison is made using various spatial covariance models ranging from stationary isotropic to nonstationary models.     

人力资本积累下的技术进步对能源消耗型产业经济增长的影响

可持续的经济增长受到技术、资本、能源、环境等诸多要素投入的影响。本文构建并刻画了基于能源与环境约束的能源消耗型产业在考虑人力资本积累(涉及到原始能源的二次开发利用和产业污染物的治理)的技术进步影响下,实现其产业的稳态经济增长路径,并尝试分析了技术进步形成的污染治理和能源回收再利用对产业经济增长的影响。     

劳动力流动与第三产业的内生性研究——基于新经济地理的实证分析

根据新经济地理学理论构建劳动力流动与第三产业的联立方程,系统分析2006～2009年中国各省市劳动力流动与第三产业发展的影响因素及两者之间的内生性关系。研究发现,流入地的经济收入、第三产业的发展水平和经济开放度是吸引劳动力流入的主要动力;随着农村净收入的提高,城乡收入差距缩小,劳动力的流动性随之降低;资本、劳动力和市场因素会促进第三产业的发展,但过多的政策管制却阻碍了第三产业的发展,而且城市化策略在不同区域的不同发展阶段其效果不同;劳动力流动与第三产业发展是相互作用的,从而引起劳动力在东部的聚集效应和在中西部的分散效应。     

新生代农民工就业条件行业差距实证研究

本文利用全国流动人口动态监测调查数据,选取流动人口典型就业行业（包括制造业、建筑业、批发零售和住宿餐饮业）。探讨行业之间就业条件差距的代际变化情况,分析新生代农民工丁资、劳动强度、社会保险状况等就业条件的行业差距及其影响因素。研究结果表明,不同行业农民工就业条件的代际差距有明显扩大趋势,反映出行业发展的不均衡与部分劳动者的权益损害。行业待遇差距过大,将会恶化劳动力供给结构不均衡,甚至加剧近些年出现的“用工荒”现象,不利于我国宏观经济的健康发展。     

Variable selection in linear regression analysis with alternative Bayesian information criteria using differential evaluation algorithm

In statistical analysis, one of the most important subjects is to select relevant exploratory variables that perfectly explain the dependent variable. Variable selection methods are usually performed within regression analysis. Variable selection is implemented so as to minimize the information criteria (IC) in regression models. Information criteria directly affect the power of prediction and the estimation of selected models. There are numerous information criteria in literature such as Akaike Information Criteria (AIC) and Bayesian Information Criteria (BIC). These criteria are modified for to improve the performance of the selected models. BIC is extended with alternative modifications towards the usage of prior and information matrix. Information matrix-based BIC (IBIC) and scaled unit information prior BIC (SPBIC) are efficient criteria for this modification. In this article, we proposed a combination to perform variable selection via differential evolution (DE) algorithm for minimizing IBIC and SPBIC in linear regression analysis. We concluded that these alternative criteria are very useful for variable selection. We also illustrated the efficiency of this combination with various simulation and application studies.     

On the use of the selection matrix in the maximum likelihood estimation of normal distribution models with missing data

In this article, by using the constant and random selection matrices, several properties of the maximum likelihood (ML) estimates and the ML estimator of a normal distribution with missing data are derived. The constant selection matrix allows us to obtain an explicit form of the ML estimates and the exact relationship between the EM algorithm and the score function. The random selection matrix allows us to clarify how the missing-data mechanism works in the proof of the consistency of the ML estimator, to derive the asymptotic properties of the sequence by the EM algorithm, and to derive the information matrix.     

邯郸市轻重工业比例的失衡及其治理

轻重工业比例失衡,制约了邯郸市工业乃至整个经济的发展,是近年来邯郸市经济相对落后的重要原因。因此,要想保证邯郸市经济持续稳定增长,必须在推动重工业提升产业层次,由注重外延增长转变为注重内涵提升的基础上,协调轻重工业比例关系,加快轻工业的发展。     

论网络信息资源的组织与管理

本文在论述传统文献资源组织与管理的基础上,提出了网络信息资源组织与管理的创新运作方式。     

基于分形的国民经济动员信息系统结构模型研究

国民经济动员信息化是一项复杂的系统工程,信息化建设需要有前瞻性的系统规划作指导。国民经济动员关系到经济领域的各个方面,涉及的信息量大、类型复杂、分布范围广,信息系统的环境复杂多变。本文总结分析了国民经济动员信息的特点,提出建立信息结构的思路并分析了信息结构的描述方法。建立了基于分形的信息系统结构模型。     

逆向选择下信息系统的选择标准

逆向选择情形下,代理人拥有的私人信息对委托人与代理人博弈的均衡结果有着至关重要的影响.实际上,逆向选择过程中委托人面临的问题可分为两个阶段:一是对信息系统的选择,二是在给定信息系统下的机制设计问题.现有文献往往关注后一阶段信息系统既定情况下的机制设计问题,本文研究的是第一阶段信息系统的选择标准.在代理人效用函数特定的基础上,当代理人能力的分布函数G(y)一阶随机占优于分布函数F(y),委托人相对于信息系统G(y)更偏好于信息系统F(y),即一阶随机占优(FSD)是逆向选择情形下信息系统占优的充分条件.