跨境电子商务背景下中非贸易发展浅析

】中非贸易对中国和非洲各国的经济发展有着重要意义。基于此，本文分析了跨境电子商务背景下中非贸易的发展现状和存在的问题，认为 非洲电子商务平台之间存在竞争愈发激烈、物流成本昂贵、贸易摩擦频发、专业人才不足的问题，提出了加强中非经贸合作和交流、建立物流风险应 急机制、培养中非跨境电子商务专业人才、帮助非洲进行基础设施建设、充分挖掘国内消费潜力、丰富产品品类，推动产品本土化的建议。     

地位竞争动机对个体知识共享行为的影响

知识共享行为是学术界和企业界关注的焦点，虽然以往文献从多个角度和层次研究了组织中的知识共享行为，但忽视了地位竞争动机对个体知识共享决策的内在作用机制。基于地位竞争动机差异，将个体地位动机区分为支配型和威望型，以职场排斥为中介变量、组织公平氛围为调节变量，构建地位竞争动机对知识共享行为的影响过程模型，基于13个组织630套上下级配对样本数据进行实证检验。结果显示，支配型地位竞争动机负向影响知识共享行为，威望型地位竞争动机正向影响知识共享行为，职场排斥、组织公平氛围分别发挥中介效应和调节效应。结果为知识共享领域研究提供了新的视角和框架，揭示了地位竞争动机对知识共享促进和抑制作用的两面性，对企业管理实践有一定的现实意义。     

The Chinese Stock Dividend Puzzle

In this paper, we examine the announcement effects of dividends with an emphasis on stock dividends in China's capital market. We find that dividend-paying stocks exhibit significantly positive abnormal returns while non-dividend-paying stocks show a negative announcement effect. Further, we document that the cumulative abnormal returns for pure stock dividends and combined dividends are the main drivers of this announcement effect. In contrast, pure cash dividend stocks experience no significant price run-up before announcement. The significant announcement effect of stock dividends is robust to controlling the earnings surprise effect. We offer some discussion of the possible explanations.     

零工经济时代数字平台控制劳动力的供给行为

本文首先基于委托-代理模型构建了一个数字平台控制劳动力供给的行为经济学模型,从理论上分析了数字平台控制劳动的方式和心理机制;然后建立了一个赫克曼(Heckman)选择模型,利用Uber的大数据实证分析了网约车司机的劳动决策.研究结果表明:(1)在零工具有参考点偏好的前提下,数字平台通过高货币激励或高目标奖励使零工劳动者的参考点具有适应性,进而避免其过早地陷入“收入目标”行为;(2)数字平台利用零工劳动者的厌恶损失偏好,对其实施控制以延长工作时间;(3)网约车司机存在“收入目标”行为,且该行为呈现出动态性的特点;(4)收入激励和“峰时”溢价对网约车司机的工作概率和工作时间具有显著的正影响,且在一天的某个时间段内能够抑制网约车司机的“收入目标”行为.可见,零工经济时代到来,一方面提高了劳动力资源配置效率;另一方面,数字平台通过劳动控制变相延长了零工的劳动时间,加剧了剥削.     

加强政策事中事后评估的思考

党的十九届四中全会明确提出要强化决策执行、评估、监督,做好政策评估对优化政府职能、推动国家治理体系和能力现代化有积极作用。加强政策运行情况的评估,应从优化评估工作机制、完善和培育评估机构、强化评估结果的应用入手,不断提升评估工作质量,形成适应中国特色社会主义现代化治理体系的事中事后政策评估机制。     

微波提取酵母胞内甘油的分析方法初探

本文探讨了面包酵母胞内甘油分析的预处理方法——微波破碎法。通过单因素实验分析,确定了胞内甘油的提取条件:酵母细胞用微波破碎3次、每次破碎10 s、间隔5 s,然后用10 mL蒸馏水提取30 min得到胞内甘油,此法简便、易提取,适用于天然产物的快速提取。     

绿色环保军用食品的研究与进展

军用野战食品是保证战士饮食的重要食物,对提高战士的身体素质、提升军队的战斗力具有至关重要的作用。各国军队首脑对此都十分重视,将此项内容作为军队建设的重要内容。基于此,本文综述了相关学者对军用食品的研究,以期为相关学者提供借鉴。     

Adoption of farm‐based irrigation water‐saving techniques in the Guanzhong Plain,China

This article analyses adoption of farm‐based irrigation water saving techniques, based on a cross‐sectional data set of 357 farmers in the Guanzhong Plain, China. Approximately 83% of the farmers use at least one farm‐based water‐saving technique. However, the traditional, inefficient techniques border and furrow irrigation are still prevalent whereas the use of advanced, more efficient techniques is still rather rare. We develop and estimate an adoption model consisting of two stages: awareness of water scarcity and intensity of adoption. We find that awareness of water scarcity and financial status enhance adoption of more advanced techniques whereas access to better community‐based irrigation infrastructure discourages it. We furthermore find both community‐based irrigation infrastructure and farm‐based irrigation water‐saving techniques have mitigating effects on production risk. From the results it follows that adoption can be stimulated via financial support and via extension aimed at enhancing awareness of water scarcity.     

Latent vs. Observed Variables: Analysis of Irrigation Water Efficiency Using SEM and SUR

In this paper we compare conceptualising single factor technical and allocative efficiency as indicators of a single latent variable, or as separate observed variables. In the former case, the impacts on both efficiency types are analysed by means of structural equation modeling (SEM), in the latter by seemingly unrelated regression (SUR). We compare estimation results of the two approaches based on a dataset on single factor irrigation water use efficiency obtained from a survey of 360 farmers in the Guanzhong Plain, China. The main methodological findings are that SEM allows identification of the most important dimension of irrigation water efficiency (technical efficiency) via comparison of their factor scores and reliability. Moreover, it reduces multicollinearity and attenuation bias. It thus is preferable to SUR. The SEM estimates show that perception of water scarcity is the most important positive determinant of both types of efficiency, followed by irrigation infrastructure, income and water price. Furthermore, there is a strong negative reverse effect from efficiency on perception.