The effect of board size on shareholder value: Evidence from bank mergers and acquisitions

This study examines the effect of board size on the economic impact of bank mergers and acquisitions (M&A) in the US. Using a hand-collected dataset of 508 M&A between 2012 and 2018, we find that board size is negatively related to acquirer excess returns. In an additional analysis, we show that large boards have positive value implications for banks that combine the CEO and chairman roles as well as for large banks. Our findings indicate that a “one-size-fits-all” approach to board size is not necessarily in the interests of shareholders; instead, a more flexible and proactive formulation is needed.     

行政耦合、新型关系网络及其于乡村治理的作用机制研究

作为中国特色的政府治理策略定制，“行政耦合”是指政府或政府行为通过一系列途径实现与乡村社会权力结构的有效融合，从而实现政府有效治理的政策工具。这种工具在乡村治理中表现出运作主体多元化、服务导向、协同合作的运作特征。本文以贵州省新民镇的“四在农家，美丽乡村”建设作为案例样本，分析基层政府“行政耦合”所形成的新型耦合式关系网络对乡村治理的作用机制。这种新型耦合式关系网络是政府体制吸纳与乡村社会政治参与的均衡演进的结果，二者的交互作用促进和强化乡村治理目标的实现，展现了其各自的价值。在乡村振兴战略背景下，对其在乡村治理实践中“沁润式”发展所产生的深层矛盾和风险进行反思，以期为乡村治理提供理论指引和实践参考。     

村庄非农化、社会资本与农民家庭收入

聚焦于社会资本影响农民收入的微观和宏观机制，利用中国家庭动态追踪调查数据构建“家庭—村庄”两个层次的交互模型，考察了不同生产情景下社会资本效用的差异性以及村庄非农化过程对其产生的影响。研究表明：在微观层面，家庭社会网络规模的扩张能够同时提高农业收入和非农收入，而社会网络结构异质性的提高只有利于非农收入的增长；并且随着村庄非农化程度的提高，社会网络的效应对于农业收入逐步减弱，而对于非农收入的影响则逐步增强。在宏观层面，村庄社会融合程度的提高仅有利于农民农业收入的增长，但随着非农化进程的推进，村庄集体社会资本在农业生产中所凸显的优势将会逐渐削弱。这预示着，中国农村非农经济的迅猛发展正逐步改变乡村社会资本的经济意涵。     

An omnibus two-sample test for ranked-set sampling data

We develop an omnibus two-sample test for ranked-set sampling (RSS) data. The test statistic is the conditional probability of seeing the observed sequence of ranks in the combined sample, given the observed sequences within the separate samples. We compare the test to existing tests under perfect rankings, finding that it can outperform existing tests in terms of power, particularly when the set size is large. The test does not maintain its level under imperfect rankings. However, one can create a permutation version of the test that is comparable in power to the basic test under perfect rankings and also maintains its level under imperfect rankings. Both tests extend naturally to judgment post-stratification, unbalanced RSS, and even RSS with multiple set sizes. Interestingly, the tests have no simple random sampling analog.     

河北省电子认证发展现状及对策建议

电子认证是保障网络及信息安全的重要手段。通过对河北省电子认证工作现状、取得的成绩和存在问题进行深入剖析,提出创新政府监管,加强人力、物力投入,鼓励开展跨省、跨境互认,推动电子认证服务创新升级,开展跨地区、跨行业电子认证协同,共建全国性密码与密钥基础设施等发展建议。     

Cognitive abilities,self-efficacy,and financial behavior

This paper investigates the effect of cognitive abilities on financial behavior among older adults. Using the U.S. Health and Retirement Study, I find that cognitive abilities significantly affect financial behavior through two channels: ability and self-efficacy. People with higher cognition scores achieve better financial outcomes. This positive association is especially strong in tasks having high demand of cognitive abilities, which confirms the ability channel of the cognitive ability effect. In addition, there is evidence for the self-efficacy channel as a secondary source of cognitive influence. Lower cognitive abilities decrease people’s sense of self-efficacy, which, in turn, significantly decreases financial management efficiency. The findings have important policy implications, specifically that more effort is needed to assist the growing older population through the cognitive aging process and that noncognitive skills, as a secondary source of influence, also warrant attention.     

全媒体时代主流媒体的数据化生存与发展

基于互联网连接的媒体平台，正在成为各类原生数据的源发地和汇聚中心，对大数据进行整合及应用的能力，将成为未来媒体平台运营的核心能力。建构在互联网平台之上的主流媒体必然要经历从信息总汇向数据总汇的转变，在这一过程中，媒体的业态、社会功能都将发生重大变化。伴随全媒体时代信息技术的快速发展，新闻传播呈现出新的特点和规律：传播主体大众化；传播容量海量化；传播方式交互化；传播手段多维化；传播时效全时化。在这样的背景下，主流媒体应不断进行数据化的探索和创新，基于5G网络，通过大数据技术运用，强化数据库建设，以此为基础，运用基于大数据的人工智能技术改变内容生产和分发方式，并以之作为内容监管的有力武器。未来基于大数据分析的综合业务推动自身产业结构优化。     

浙江省城市绿色技术创新效率评价及影响因素分析

基于网络DEA模型和Malmquist指数模型，利用浙江省11个地级市的2011-2020年的数据，以降维后的污染指数为非期望产出对绿色技术创新效率进行测度和分析。发现:浙江各市总体上成果转化阶段的效率优于研发阶段，城市间发展差异较大；整体TFP指数均值为1.121，其提升主要源自技术进步；城镇化水平、产业结构优化、对外开放、政府干预和研发强度对绿色技术创新效率有促进作用，但经济发展水平与绿色技术创新效率的U型关系不显著。     

An Optimization‐Based Framework for the Identification of Vulnerabilities in Electric Power Grids Exposed to Natural Hazards

This article proposes a novel mathematical optimization framework for the identification of the vulnerabilities of electric power infrastructure systems (which is a paramount example of critical infrastructure) due to natural hazards. In this framework, the potential impacts of a specific natural hazard on an infrastructure are first evaluated in terms of failure and recovery probabilities of system components. Then, these are fed into a bi‐level attacker–defender interdiction model to determine the critical components whose failures lead to the largest system functionality loss. The proposed framework bridges the gap between the difficulties of accurately predicting the hazard information in classical probability‐based analyses and the over conservatism of the pure attacker–defender interdiction models. Mathematically, the proposed model configures a bi‐level max‐min mixed integer linear programming (MILP) that is challenging to solve. For its solution, the problem is casted into an equivalent one‐level MILP that can be solved by efficient global solvers. The approach is applied to a case study concerning the vulnerability identification of the georeferenced RTS24 test system under simulated wind storms. The numerical results demonstrate the effectiveness of the proposed framework for identifying critical locations under multiple hazard events and, thus, for providing a useful tool to help decisionmakers in making more‐informed prehazard preparation decisions.     

考虑重复购买因素的品牌竞争对新产品扩散的影响研究——基于小世界网络的仿真环境

在对品牌竞争影响要素分析的基础上，考虑重复购买在新产品扩散过程中的调节效应，构建以消费者微观采纳机制为核心的新产品扩散的阈值模型，在小世界网络仿真情境下，运用多智能仿真方法对品牌竞争与新产品扩散之间的影响关系进行分析，研究结果表明：转换成本对新产品扩散的速度和深度的影响存在一定的"条件区域"，在该区域之外两者不存在显著的影响关系；进入时间与两种竞争性品牌的扩散速度存在一致的负向的影响关系，而对两种竞争性品牌的扩散深度的影响方向则相反；在此过程中，重复购买系数起着一定的调节效应，会在一定程度上放大或缩小转换成本及进入时间对新产品扩散的影响效应。通过本文的研究，不仅可以进一步丰富和完善竞争性产品创新扩散的相关理论，也可以为企业的新产品推广实践提供决策支持。