农村留守儿童家庭教养方式的社会学分析

通过对农村"留守儿童"家庭教养方式的现状进行描述和归纳,分析产生不同类型的家庭教养方式的原因,以期引起社会各界对留守儿童群体的关注,更好地指导农村"留守儿童"的家庭教养方式,提高家庭教育质量,促进儿童的健康成长。     

对耕地利用率影响因素及影响效应的统计分析

耕地承包农户的户主年龄、家庭非农收入、土地转让行为选择、农户择业意愿、耕地条件与环境等因素与耕地利用率之间存在显著相关。对此,政府首先必须加强对农民的重农教育,增强农民珍爱耕地的自觉性;其次,应创新耕地管理制度,引导土地合理流转;其三,推进农村土地流转规范,提升耕地资产价值效能;其四,加大支农惠农政策力度,提高农业比较收益;其五,扩大对农村投入,改善农村农业基础设施建设。     

额外资源按需分配方法研究

文献Wei Quanling等^[1]的最后一段提出了这样一类额外资源分配问题：假设有一些额外的投入资源将要分配给全部或者部分决策单元,如果我们希望分配结果对于整个系统（该系统由全部决策单元组成）来说是最有益的,那么应当如何分配这些额外的投入资源?他们同时还指出系统中哪些决策单元能够获得额外的投入资源,这不仅取决于决策单元的效率,还需要考虑规模报酬。针对此类问题,本文提出一种额外资源按需分配方法：首先,综合决策单元的技术效率与其投影点的规模弹性构建发展曲线,并由决策单元的发展曲线获知其投入变动与产出变动的对应关系;然后,把额外资源分成若干等份,依次分配每一个等份的额外资源,每次分配使系统的总产出增加实现最大,直至分配完全部的额外资源,或者分配某一份额外资源不再带来任何的产出增加,分配就会停止;最后,把决策单元在每一次分配过程中获得的额外资源进行累加,得到这个决策单元最终的分配结果。全文的最后分别在"一个投入一个产出"和"两个投入一个产出"情况下给出两个具体的分配算例。分配结果表明,这种按需分配方法不会缩减任意一个决策单元当前占有的投入资源数量,并且还可以有效地在辨识出某种额外资源在规模上和结构上存在的冗余,从而有效地避免不必要的分配。     

Dual‐Donor Organ Exchange

Owing to the worldwide shortage of deceased‐donor organs for transplantation, living donations have become a significant source of transplant organs. However, not all willing donors can donate to their intended recipients because of medical incompatibilities. These incompatibilities can be overcome by an exchange of donors between patients. For kidneys, such exchanges have become widespread in the last decade with the introduction of optimization and market design techniques to kidney exchange. A small but growing number of liver exchanges have also been conducted. Over the last two decades, a number of transplantation procedures emerged where organs from two living donors are transplanted to a single patient. Prominent examples include dual‐graft liver transplantation, lobar lung transplantation, and simultaneous liver‐kidney transplantation. Exchange, however, has been neither practiced nor introduced in this context. We introduce dual‐donor organ exchange as a novel transplantation modality, and through simulations show that living‐donor transplants can be significantly increased through such exchanges. We also provide a simple theoretical model for dual‐donor organ exchange and introduce optimal exchange mechanisms under various logistical constraints.     

城镇劳动力市场城乡分割的程度与特征 ——基于浙江数据的经验研究

 劳动力市场的城乡分割意味着经济效率的损失,一直来备受关注。本文构建了一个劳动力市场城乡分割指数,基于中国城镇住户调查浙江省的数据,测量了城镇劳动力市场城乡分割的程度。结果显示：在工资回报层面,相对高端领域的分割程度弱于相对低端领域,但在就业机会层面,相对高端领域的分割程度强于相对低端领域。为此我们建议：劳动力市场管理上重点关注低端劳动力市场中城乡劳动者的同工同酬问题,公共政策设计上重点关注高端劳动力市场中城乡劳动力的平等就业机会问题。     

Exploring Partial Order of European Countries

Partial Order Theory has been recently more and more employed in applied science to overcome the intrinsic disadvantage hidden in aggregation, if a multiple attribute system is available. Despite its numerous positive features, there are many practical cases where the interpretation of the partial order can be rather troublesome. In these cases the analysis of underlying dimensions could be useful to uncover particular data structures. The paper shows a way of addressing the problem with the help of an actual case study, which deals with European opinions on services of general interest. In particular, a partial order of countries is firstly provided and then a method to detect dimensions is discussed and applied. The analysis stems directly from the Partially Order Set (poset) and Lattice theory with particular references to dimension theory and Formal Concept Analysis. The study is eventually able to pinpoint role and relevance of different attributes characterizing EU countries which are used to define the partial order.

基于Logit模型的区域集镇系统需求分析及规模确定研究

集镇迁建并非简单的将集镇按照原规模从一个地方搬到另一个地方,集镇迁建规模的大小．应该根据迁入区的实际需求（需求规模）来确定,需求的大小主要取决于村民对集镇的选择行为,即越多的人选择到某个集镇进行活动,该集镇的需求规模越大,反之越小。影响集镇需求的因素很多,包括交通时间、交通费用、集镇服务种类、服务质量等,本文将其概括为广义费用和集镇效用（服务能力）,建立反映村民选择行为的Logit模型分析集镇需求情况,并将其应用于区域集镇系统布局优化中,以我国西部某地为例进行实证分析,反映搬迁前后一定区域内各榘镇需求规模的变化,同时计算出新集镇的需求规模,为集镇迁建规模的确定及其布局优化提供科学的参考。     

Generalized simultaneous confidence regions for regression coefficients and their ratios

This study constructs a simultaneous confidence region for two combinations of coefficients of linear models and their ratios based on the concept of generalized pivotal quantities. Many biological studies, such as those on genetics, assessment of drug effectiveness, and health economics, are interested in a comparison of several dose groups with a placebo group and the group ratios. The Bonferroni correction and the plug-in method based on the multivariate-t distribution have been proposed for the simultaneous region estimation. However, the two methods are asymptotic procedures, and their performance in finite sample sizes has not been thoroughly investigated. Based on the concept of generalized pivotal quantity, we propose a Bonferroni correction procedure and a generalized variable (GV) procedure to construct the simultaneous confidence regions. To address a genetic concern of the dominance ratio, we conduct a simulation study to empirically investigate the probability coverage and expected length of the methods for various combinations of sample sizes and values of the dominance ratio. The simulation results demonstrate that the simultaneous confidence region based on the GV procedure provides sufficient coverage probability and reasonable expected length. Thus, it can be recommended in practice. Numerical examples using published data sets illustrate the proposed methods.     

The social benefits of water and sanitation projects in Northern Colombia: Cost‐Benefit Analysis,the Water Poverty Index and beyond

Water, and Sanitation projects play an important role in alleviating water‐related poverty in developing countries. There are several methodologies that will not only assess the performance of these projects but will also help to better identify the problem and its characteristics, and to improve the efficiency of the investment. The Water Poverty Index is one of them. It is a very useful tool that helps to measure water stress at the household level in a holistic way, and to identify priorities. It is important, however, to complement it with a Cost‐Benefit Analysis that will take into account the costs of the project. A case study in Northern Colombia illustrates this point.     

国有商业银行资本市场业务研究

本文首先从国际金融界混业经营 ,国内银行、保险、证券三业互相渗透共同发展 ,我国资本市场发展对银行传统业务的冲击 ,以及加入 WTO挑战的需要等方面论述了国有商业银行拓展资本市场业务的客观现实性。其次 ,从资本市场规模、银行和证券公司、基金、保险公司的业务合作领域 ,以及合作的层次和市场发展潜力等方面阐述了国有商业银行进行资本市场业务创新的动因及其目前在资本市场业务方面存在的问题和解决办法。进而分析了进一步拓展资本市场业务从建立战略同盟、壮大资金实力和实现综合经营有效切入的问题