A Blueprint for Full Collective Flood Risk Estimation: Demonstration for European River Flooding

Floods are a natural hazard evolving in space and time according to meteorological and river basin dynamics, so that a single flood event can affect different regions over the event duration. This physical mechanism introduces spatio‐temporal relationships between flood records and losses at different locations over a given time window that should be taken into account for an effective assessment of the collective flood risk. However, since extreme floods are rare events, the limited number of historical records usually prevents a reliable frequency analysis. To overcome this limit, we move from the analysis of extreme events to the modeling of continuous stream flow records preserving spatio‐temporal correlation structures of the entire process, and making a more efficient use of the information provided by continuous flow records. The approach is based on the dynamic copula framework, which allows for splitting the modeling of spatio‐temporal properties by coupling suitable time series models accounting for temporal dynamics, and multivariate distributions describing spatial dependence. The model is applied to 490 stream flow sequences recorded across 10 of the largest river basins in central and eastern Europe (Danube, Rhine, Elbe, Oder, Waser, Meuse, Rhone, Seine, Loire, and Garonne). Using available proxy data to quantify local flood exposure and vulnerability, we show that the temporal dependence exerts a key role in reproducing interannual persistence, and thus magnitude and frequency of annual proxy flood losses aggregated at a basin‐wide scale, while copulas allow the preservation of the spatial dependence of losses at weekly and annual time scales.     

适应性市场假说及其在中国资本市场的实证

金融危机近些年爆发频繁,传统市场理论如有效市场假说和行为金融面对复杂的现实金融世界未能给出合理解释.Lo提出的适应性市场假说则弥合了这两个学派的分歧,逐渐引起了学术界的重视.本文尝试从动态市场效率、时变贝塔和技术交易策略演变这三个角度对适应性市场假说能否解释我国资本市场进行实证研究.研究发现:我国股票市场效率在动态变化,无效的时段与金融危机或政策巨变等重大事件联系密切;股市风格指数贝塔随市场环境变化而改变;技术交易策略绩效随投资者适应环境变化而演变.研究结果表明,适应性市场假说相比有效市场假说和经典资本资产定价模型,能够更好地解释我国资本市场上述现象.最后对投资者如何根据市场环境变化制定适应性投资策略给出几点建议.     

一种新的金融动态横截面估计方法——基于中国股票市场条件定价模型评估的应用与扩展

大多数资产定价模型常常用静态横截面回归(the static cross-sectional regression)进行定价表现评估,从而投资组合回报率的时间变化性并不能被时变的风险承载或者(和)时变的风险溢价所解释.本文从经济学的角度,运用一种新的金融动态横截面回归(the dynamic cross-sectional regression),首次考察了基于中国股票市场和美国股票市场的条件资产定价模型的定价表现:股票市场投资组合回报率的时变性是否能被时变的风险溢价所解释.本文发现,短期收益反转和流通市值加权市场换手率为条件变量的条件资本资产定价模型和基于消费的条件资本资产定价模型,能更好的解释中国股票投资组合的回报时变性,其时变性主要来自于时变的风险溢价.另外,本文发现一些拥有持续(persistence)和缓慢变化(slow-moving)特性的条件变量更能够解释横截面投资组合的时变回报.     

舆论危机的异化极化效应研究

随着Web2.0时代的到来,网络媒体逐渐成为舆论生成、传播和交锋的主阵地,舆论危机的形成及其异化也成为日益突出的社会风险问题.本文以舆论的异化演化机理为研究对象,通过梳理典型事件舆论话题的异化过程,对其基本内涵、表现形式和演化模式等进行系统总结.随后,研究以舆论超网络模型为基础,借鉴社会影响理论的基本原则,提出舆论异化机理的极化算法,并对其具体流程进行解析和实现.最后,本文以“7·23甬温动车事故”为例,对舆论危机的异化极化过程和影响因素进行系统仿真和实证分析.     

Optimal Dynamic Order Scheduling under Capacity Constraints Given Demand‐Forecast Evolution

We consider a manufacturer without any frozen periods in production schedules so that it can dynamically update the schedules as the demand forecast evolves over time until the realization of actual demand. The manufacturer has a fixed production capacity in each production period, which impacts the time to start production as well as the production schedules. We develop a dynamic optimization model to analyze the optimal production schedules under capacity constraint and demand‐forecast updating. To model the evolution of demand forecasts, we use both additive and multiplicative versions of the martingale model of forecast evolution. We first derive expressions for the optimal base stock levels for a single‐product model. We find that manufacturers located near their market bases can realize most of their potential profits (i.e., profit made when the capacity is unlimited) by building a very limited amount of capacity. For moderate demand uncertainty, we also show that it is almost impossible for manufacturers to compensate for the increase in supply–demand mismatches resulting from long delivery lead times by increasing capacity, making lead‐time reduction a better alternative than capacity expansion. We then extend the model to a multi‐product case and derive expressions for the optimal production quantities for each product given a shared capacity constraint. Using a two‐product model, we show that the manufacturer should utilize its capacity more in earlier periods when the demand for both products is more positively correlated.     

中国城市商业银行盈利能力影响因素分析——基于50家商业银行的微观数据

基于2009-2015年期间国内50家城市商业银行(城商行)的微观数据,采用动态面板数据模型实证检验了资产负债结构及其他宏微观因子对城商业银行盈利能力的影响。研究结论表明:负债及资产结构对城商行的盈利能力具有显著的影响,一般性存款占负债的比重、贷款占资产的比重均与其盈利水平显著正相关;城商行的资产质量及成本控制水平越高,盈利能力也越强;规模越大并不意味着盈利能力越强,那些规模较小的城商行因为聚焦于中小客户群体、具有更高的定价话语权而能够获取更高的盈利;GDP增长率、货币政策等外部宏观环境并不会显著影响城商行的盈利水平。因此,城商行不应追求单纯的规模扩张而应着力强化资产负债统筹管理,并立足自身资源禀赋及市场定位,走差异化、特色化发展道路。     

动态能力理论视角下企业社会责任行动提升的研究

企业承担相应的社会责任已经取得了学术界和业界的基本认同,在我国当前的社会环境下,通过履行相应的社会责任既有助于企业经济目标的实现,也符合政府提倡建立“和谐社会”的社会总目标的要求。文章从动态能力理论视角出发,对于动态能力,企业社会责任态度,以及企业社会责任提升的关系进行了研究分析,建立了三者之间的关系模型框架。研究表明动态能力通过企业社会认知水平和组织价值观的影响作用,促进了企业社会责任态度的形成,进而能够提升该企业的社会责任行动水平。     

西南边疆多民族地区社会动力机制

在推进和谐社会建设的进程中,西南边疆多民族地区社会动力机制运行不断完善,但还存在许多问题：社会发展的经济动力不足,政府的工作存在比较大的改进空间,法律法规的规范力处在较低层次上,社会成员的认知程度和文化需求的现实满足程度还偏低。实现西南边疆多民族地区社会和谐必须把推动社会发展的经济动力、政治动力、文化动力等充分激活,让创造社会价值和财富的源泉充分进发。     

谈渤海国对日本交往的两个问题

渤海国是唐朝时期中国的一个边疆民族政权,与日本具有一些相同的文化因素,物产丰富,造船技术和航海技术先进,这些是其对日本交往的有利条件。在这样的条件下,渤海进行了长期的对日交往,是中日关系的一个组成部分。渤海对日本的交往,影响了东北亚战略格局,满足了双方人民的经济需要,促进了唐文化的传播,给东北亚海上丝绸之路赋予了新的内涵,对于东北亚经济文化交流具有重要的意义。     

浅析政治因素在美语词汇中的反映

随着社会的发展和人类思维的更新,语言不断被输入新鲜血液。美式英语,作为英语这门古老而优秀的语言的分支,也经历了无数次变革大潮的冲击。其中政治因素对美语词汇的影响很大,总统竞选、种族歧视、女权运动都对美语词汇产生影响。美语词汇中出现了大量的新词与新义。通过对政治因素和美语词汇最新发展的了解,有助于美语学习者更好地掌握美语这门语言。