学习迁移的系统理论:PPEE理论模型的建构和意义

学习是人类社会永恒的主题。为了更好地利用过去的经验，增强学习效果，个人和组织进行学习迁移具有重要意义。学习迁移是指将在以往通过学习或解决问题所获得的经验，用于解决之后所遇到的问题。本文力图建立系统的学习迁移理论，研究人、问题、环境的因素对于学习迁移的影响。本文采用理论推导的研究方法，在前人研究的基础上，提出相应的理论模型。本文运用系统的观点，构建了学习迁移的PPEE理论模型，认为人的因素、问题的因素、人和问题的交互作用、以及环境的调节作用，会共同影响学习迁移的效果。本理论主要从五个方面论述学习迁移的机制。首先，将人的因素按照不同层面划分为后端基本能力、中端心理过程、前端知识结构，讨论了其各自对学习迁移效果的直接影响。其次，将问题的因素划分为形象相似性和抽象相似性，并根据这两个维度构建了四种问题间关系类型，并探究了其与学习迁移效果之间的关系。第三，同时考虑人的因素和问题的因素，研究了二者之间的互动对于学习迁移效果的影响。第四，将环境因素划分为时间紧迫性和空间重要性两个维度，探讨了人和环境，以及问题和环境之间的互动对学习迁移效果的影响。第五，基于系统整体的方面，研究人、问题、环境三者之间的互动对学习迁移效果的交互影响。本文还认为，该模型不仅适用于个人，也同样适用于团队、组织、地区、甚至国家和社会等各个层面，影响各个层面主体的学习迁移。本文最后总结了研究的理论和实践贡献，并提出了未来研究课题。本文对丰富学习理论、特别是学习迁移理论，以及推动教育和管理实践的发展进步具有重要的意义。     

Cash Transfers and Children's Education and Labour among Malawi's Poor

This article examines the impact on children's education and labour of monthly cash grants targeted on ultra‐poor households and designed to reduce poverty and enable families to invest in human development. It conducts a randomised community trial, with baseline and endline surveys of intervention and control households; verifies school enrolment; and completes key‐informant interviews and focus‐group discussions. Compared with non‐beneficiaries, intervention children experienced a 5 percentage point difference in enrolment, higher educational expenditures, fewer absences, and a 10 percentage point decrease in labour outside the home. Qualitative data confirm the quantitative findings. Transfers to poor households had a positive impact. However, the Malawian educational system needs to be improved for short‐term impacts to lead to long‐term development in human capital.     

Smooth tail-index estimation

The two parametric distribution functions appearing in the extreme-value theory – the generalized extreme-value distribution and the generalized Pareto distribution – have log-concave densities if the extreme-value index γ∈[?1, 0]. Replacing the order statistics in tail-index estimators by their corresponding quantiles from the distribution function that is based on the estimated log-concave density ? f _n leads to novel smooth quantile and tail-index estimators. These new estimators aim at estimating the tail index especially in small samples. Acting as a smoother of the empirical distribution function, the log-concave distribution function estimator reduces estimation variability to a much greater extent than it introduces bias. As a consequence, Monte Carlo simulations demonstrate that the smoothed version of the estimators are well superior to their non-smoothed counterparts, in terms of mean-squared error.     

编辑审稿中的非学术因素及排除之策

学术期刊是学术和学科建设的重要阵地,应以学术性作为编辑审稿工作的唯一标准。然而,在现有学术评价体制的影响下,这一工作受到了诸多非学术因素的消极干扰,如以作者身份的高低而非稿件质量的高低来取舍稿件。这一非学术性倾向直接影响了审稿的公正性,也削弱了编辑审稿活动的意义,是学术评价异化的一种反映,不利于学术研究的正常进行和健康发展。编辑应该强化责任意识,自觉克服心理因素,排除思维定势,提高学术判断力,重视学术新人的发现和扶持,从而有效发挥学术期刊在学术和学科建设中的积极作用。     

农村劳动力转移就业的多元路径选择

长期以来，我国农村劳动力转移就业基本上是以流向东部沿海经济发达地区为主的单一模式。近年来，受东部沿海地区产业向中西部地区转移进程加快和内地经济快速发展的影响，区域间的比较优势逐渐弱化，农村劳动力远距离就业的选择空间越来越大，当地政府必须通过调整农业经济结构、鼓励农民自主创业、加大招商引资力度和开辟国外劳务市场等途径探索多元转移就业路径，实现农村劳动力合理转移就业。     

Modeling stereotypes and negative self‐stereotypes as a function of interactions among groups with power asymmetries

Stereotypes is one of the most researched topics in social psychology. Within this context, negative self‐stereotypes pose a particular challenge for theories. In the current work, we propose a model that suggests that negative self‐stereotypes can theoretically be accounted for by the need to communicate in a social system made up by groups with unequal power. Because our theory is dynamic, probabilistic, and interactionist, we use a computational simulation technique to show that the proposed model is able to reproduce the phenomenon of interest, to provide novel accounts of related phenomena, and to suggest novel empirical predictions. We describe our computational model, our variables' dynamic behavior and interactions, and link our analyses to the literature on stereotypes and self‐stereotypes, the stability of stereotypes (in particular, gender and racial stereotypes), the effects of power asymmetries, and the effects of intergroup contact.     

Can the minimum living standard guarantee scheme enable the poor to escape the poverty trap in rural China?

The rural Minimum Living Standard Guarantee (Dibao) Scheme is the most important social assistance programme in rural China. However, how the rural Dibao programme affects household expenditures and whether it can enable the poor to escape the poverty trap are questions that remain largely unexplored. This study used data from the 2012 Rural Household Survey in China to investigate the impact of the rural Dibao programme on household expenditures. We found that the programme significantly improved the well‐being of low‐income households. Particularly, the programme significantly increased household expenditures on housing, education and health; furthermore, the impact was greater for households with educated household heads. However, the programme did not significantly affect household expenditures on food, transportation or farming inputs. The results imply that participation in the rural Dibao programme induces household investment in human capital, which could help to break the inter‐generational transmission of poverty and raise long‐run welfare.     

Bounded risk estimation of a linear combination of location parameters in negative exponential distributions via three-stage sampling

The paper deals with the problem of bounded risk point estimation for a linear combination of location parameters of two negative exponential distributions. Isogai and Futschik considered the situation when the location and scale parameters are all unknown. They proposed purely sequential procedures and gave second order expansions of the average sample sizes and risks. In this paper we propose three-stage procedures and derive second order expansions of the average sample sizes and risks. Further, we compare the results with those from previous work.     

土地流转中为什么会形成大量小农复制

土地流转是实现规模化经营的前提之一,然而土地流转中却出现大量小农复制,从而影响土地流转的质量和效果。运用12省(自治区)2 553份农户问卷,详细分析土地流转中小农复制的现状及其形成原因。研究发现：(1)农户流转耕地面积不大,转入户流转面积20亩及以下的约占总转入户数的60.3％,转出户流转面积5亩及以下的约占总转出户数的74.38％,转出户中仍然经营土地的约占总转出户数的74％。(2)农业分工发达使生产更加方便、文化传统形成路径依赖、禀赋效应产生“价值幻觉”以及公共服务不健全使未来存在不确定性导致转出户流转部分土地。乡土社会限制土地流转范围和经营风险增加风险感知导致转入户流转小规模土地。     

中国第三条农村城镇化道路探索--基于劳动力供给视角

当前中国以异地化转移的城镇化模式已暴露出众多的问题，这种以人口非家庭式迁移和异地转移为主要特点的城镇化发展模式不可持续，必须予以改变。通过对中国第三条农村城镇化道路进行探索可知，以企业战略推动的统筹发展型就地城镇化模式能够弥补前两条道路的不足，可以实现整村、全家同步转移，农民到市民一步的转换，具有多元正效应。在就地转移的第三条道路中，个体的搜寻成本、心理成本、交通成本和住房成本明显低于第二条道路中相应的成本，而生活成本和学习成本则相差不大。将个体劳动供给经典模型进行扩展可知，当工作时间相同时，第三条道路的劳动者个体拥有较高的实际收入和效用水平；从家庭效用模型中也可发现，家庭部门愿意提供的就地转移劳动数量要多于异地转移劳动数量，其更倾向于第三条道路下的就地转移方式。