新疆区域内人口迁移现状及效果评价

人口迁移对区域经济和社会发展将产生重要影响,需要统筹考虑。本文根据第六次全国人口普查新疆数据,以新疆南疆、北疆和东疆地区为研究单元,从迁移数量、性别、年龄、受教育水平、职业、迁移流向和迁移原因等七个方面分析了新疆区域内人口迁移的现状,即区域内迁移人口呈现“北多南少”的态势、净迁移人口中女性人口多于男性人口、中青年人口是新疆区域内迁移人口的主体、迁移人口教育水平呈现“北高南低”的态势等,同时认为务工经商和随迁家属是区域内人口迁移的主要原因;最后对新疆区域内人口迁移的效果进行了评价。     

人口老龄化必然导致资本替代劳动吗

经济学理论认为,人口老龄化会导致劳动力成本上升,从而改变企业的要素结构、通过资本替代劳动的方式应对,但不同类型的企业对老龄化做出的反应可能存在差异,需要进行深入分析。文章利用中国工业企业数据对上述问题进行了研究,实证结果显示：整体来看,人口老龄化显著提高了企业的资本劳动比,但资本劳动比的上升并不一定表现为资本对劳动的替代。在规模较大、融资约束较轻的企业,老龄化促使其用固定资产投资替代了劳动,但在规模较小和融资约束程度较为严重的企业,人口老龄化并没有显著提高其固定资产投资,只是缩小了其劳动力雇佣规模,说明企业规模和融资约束是影响企业要素结构升级的重要因素。此外,文章还发现人口老龄化主要促使企业利用资本替代低技能劳动力,而人口老龄化的资本替代劳动效应在资本密集型、生产率水平较高和非出口企业中更为显著。文章从微观企业投资视角拓展了人口老龄化的经济效应的研究范畴,并通过规模效应和融资约束角度分析了制约工业企业提高智能化生产程度的因素,从而对传统的见解提供了有益的补充。文章的研究结论能够为政府制定积极应对人口老龄化和助力企业要素结构升级的相关政策提供经验证据的支持。     

Recreation and the Environment as Cultural Dimensions in Contemporary American Society

This paper broadly explores changing outdoor recreation demands, environmental opinions and demographics in the United States. With this country's population predicted to more than double by the end of this century, it is imperative that we understand these trends and their implications for better managing our natural environment and providing opportunities for outdoor recreation in that environment. Using national survey data, we have described differences in recreation behavior (participation) and environmental attitudes nationwide across six socio-demographic factors-race, country of birth, rural-urban residence, region of the country, age and income. Results indicate that demographic differences, recreation activity choices and people's environmental positions are linked.     

Linkage Disequilibrium Mapping of Disease Susceptibility Genes in Human Populations

The paper reviews recent work on statistical methods for using linkage disequilibrium to locate disease susceptibility genes, given a set of marker genes at known positions in the genome. The paper starts by considering a simple deterministic model for linkage disequilibrium and discusses recent attempts to elaborate it to include the effects of stochastic influences, of drift, by the use of either Writht-Fisher models or by approaches based on the coalescence of the genealogy of the sample of disease chromosomes. Most of this first part of the paper concerns a series of diallelic markers and, in this case, the models so far proposed are hierarchical probability models for multivariate binary data. Likelihoods are intractable and most approaches to linkage disequilibrium mapping amount to marginal models for pairwise associations between individual markers and the disease susceptibility locus. Approaches to evalutation of a full likelihood require Monte Carlo methods in order to integrate over the large number of unknowns. The fact that the initial state of the stochastic process which has led to present-day allele frequencies is unknown is noted and its implications for the hierarchical probability model is discussed. Difficulties and opportunities arising as a result of more polymorphic markers and extended marker haplotypes are indicated. Connections between the hierarchical modelling approach and methods based upon identity by descent and haplotype sharing by seemingly unrelated case are explored. Finally problems resulting from unknown modes of inheritance, incomplete penetrance, and phenocopies are briefly reviewed.     

Constant per capita consumption paths with exhaustible resources and decaying produced capital

We introduce decay in produced capital and exogenous technical progress to the recent “Solow Model” of Asheim et al. with population growth and observe the possible collapse of the economy given too high a rate of decay. “Enough” technical progress can restore sustainable per capita consumption.     

收入分配、医疗资源与人口健康:一个跨国研究

收入分配与人口健康的关系是一个争论已久的问题。本文在总结各种理论假说和以往实证研究的基础上,使用新的、质量较好的跨国面板数据,重新检验了收入分配与人口健康的关系。本文的分析重点有二:一是收入分配对人口健康的滞后影响;二是医疗资源在收入分配与人口健康的相关关系中所起的作用。本文的主要发现是,收入不均对人口健康的确有不利影响,但这种不利影响需要10年或更长的滞后期才能充分显现出来,这种滞后性是以往使用固定效应模型的跨国研究未能检测到收入不均与人口健康具有负相关关系的主要原因。此外,医疗资源(特别是初级医疗资源)人均拥有量对人口健康有积极作用;医疗资源有可能通过某种不可观察固定因素对收入分配与人口健康的关系发生影响。这些发现有助于澄清关于收入分配与人口健康关系的争论,对医疗政策也有重要参考价值。     

城市流动人口生存现状与管理转型

我国城市流动人口目前的突出问题包括管理体制、居住条件、就业与社会稳定。城市流动人口管理转型的方向，应是建立强有力的管理协调机制，把城市流动人口就业问题纳入日程，建立流动人口社会保障机制，加强对流动人口的教育培训，探索降低治安刑事案件、加强流动人口社会治安工作的途径。     

人口结构变化、储蓄率与地区经济增长--基于PVAR模型的实证分析

本文以内生人口结构为视角,以中国各省、自治区、直辖市1990-2012年的数据为样本,通过设定面板向量自回归模型,研究人口结构、储蓄率以及经济增长之间的内在关系。结果表明：不同地区间人口结构对储蓄率和经济增长会带来不同的影响,中部地区与全国水平较为接近,各方面走势也与全国水平相似;经济增长使得少年抚养比出现持续性下降,除东部地区外,经济增长使老年抚养比也出现缓慢下降,但后续逐步趋于平稳;除东部地区外,少年抚养比的冲击使得储蓄率出现持续性上升,而老年抚养比的冲击使得储蓄率呈现出先上升后下降的特点。人口结构的变化会通过影响储蓄进而影响经济增长,而未来人口老龄化现象的加剧需要有更高的储蓄率进行应对。基于此,本文提出应通过研究现行人口政策,改变社会人口结构,提升少年抚养比,以有效应对由于“人口红利”消失对经济发展所带来的负面影响。     

高科技风投企业家项目考察阶段的非理性决策实证研究——基于人口统计特征分析

基于人口统计特征,采用列联表和多元线性回归的方法分析人口统计特征中有关的年龄、学历、留学经历与家庭结构等要素与高科技风投企业家非理性行为在项目考察阶段决策的相关性结果显示:国外留学经验、创业成功经验与企业家项目考察阶段的非理性决策存在着相关性。     

A hybrid population heuristic for the heterogeneous vehicle routing problems

The heterogeneous vehicle routing problem (HVRP) plays an important role in supply chain logistics. Two variants of HVRP are treated in this paper: one with fixed and variable costs (HVRPFD), and the other with only variable cost (HVRPD). A hybrid population heuristic that is able to solve both variants is proposed, in which a population of solutions are progressively evolved by crossovers and local searches. Computational results on a set of eight benchmark test problems from literature show that the proposed heuristic produces excellent solutions in short computing times.