采购赋能情境下平台供应链的库存风险共担策略研究

近年来,平台供应链中核心企业的采购赋能行为迅速增加,这有助于帮助供应链成员降本增效,但也可能引发核心企业自身的高库存风险。本文在同时考虑供应商产出不确定和零售商需求不确定的情境下,构建了由一个平台型电商企业、一个供应商和多个零售商组成的三级供应链系统,探讨了采购赋能情境下供应链的库存风险共担机制。研究发现,引入需求风险共担契约有助于提升供应商的生产投入水平、平台的订购量以及零售商的销售努力,并提高供应商与平台的利润。其次,引入产出风险共担契约会降低供应链成员的决策水平和利润。最后,对于不同类型的供应链风险应采取差异化的应对策略。     

我国股票市场收益率偏度对风险补偿的影响研究

收益率与波动率之间的关系(风险补偿)在金融资产定价和风险管理中至关重要,但二者之间的研究却一直没有定论。金融理论表明为正向关系,但实证却往往得到相反的结果。众所周知,尖峰厚尾以及负偏是收益率的典型特性。这些内在属性对风险补偿无疑有着重要的影响。本文研究表明,收益率的负偏和尖峰厚尾会导致风险补偿系数减小,进而导致风险补偿系数在实证当中的不确定性。虽然各个行业的夏普比率相差无几,我国股票市场的第“I”类、第“II”类风险补偿以及风险价格在不同行业之间存在较大的差异,且三者随着投资期限的增长,分别有下降、上升和轻微上升的趋势。     

多重随机环境下跨国采购和定价联合决策模型

在批发价、汇率和需求的三重随机波动环境下,考虑跨国采购与定价联合决策问题。本文主要利用随机过程来刻画批发价和汇率的随机性,并将两者的统计规律性纳入带有随机需求的决策模型的理论框架,进而给出跨国采购和定价联合决策模型及其可靠性评估机制。模型的相关结论表明:其一、不同周期的最优策略受到批发价与汇率波动的交互影响,当批发价和汇率波动性的重叠效应具有下降趋势时,销售商所采取的最优策略为增加一定的采购量,以实现系统的期望利润目标;其二、当批发价与汇率统计结构的属性为不可约遍历马氏链时,随机系统的下行风险具有良好的稳定性;其三、决策者可以通过本文提出靶向成本区间的上穿评估机制刻画随机系统的成本涨幅特征及其变化趋势,以解决供应商的最佳选择问题,从而达到了规避风险的运营目标。     

基于风险计量指标的证券组合投资的数学模型及其应用

本文建立的证券组合投资的数学模型采用风险系数β作为控制证券投资风险的参数,其经济意义明确,实用性强。该模型应用于证券组合投资,效果明显,操作方便。     

多阶段资产投资的动态规划决策模型

本文针对多阶段资产投资问题,给出了在满足一定的风险承受能力情况下的、以最终的总收益尽可能大为决策目标的资产投资组合问题的一个多阶段动态规划决策模型,从中可以求得多阶段投资的整休最优投资组合。继而讨论了其与单阶段投资模型的关系。最后把模型转化为线性动态规划模型。     

风险价值方法及其实证研究

本文详细讨论了风险价值模型,并提出了两种新的计算方法即完全参数方法和半参数方法,它们本质上是历史模拟方法或参数方法和极值理论的结合运用。通过实证研究,表明该方法优于目前流行的RiskMetrics方法。     

Risk Analysis, Systems Analysis, and Covey's Seven Habits

This article relates problem solving to the common approaches of the gestalt-holistic philosophies of systems analysis, risk analysis, and Stephen Covey's Seven Habits of Highly Effective People. Guiding principles developed on the basis of these philosophies provide the foundations for methodological frameworks that build on a plethora of theory, methods, tools, and techniques. Although systems analysis and risk analysis differ in their historical evolution and technical maturity, both study and solve problems using methodological frameworks that share a holistic vision.     

Evaluating the Effectiveness of Risk-Reduction Strategies for Consumer Chemical Products

Communication about risks offers a voluntary approach to reducing exposure to pollutants. Its adequacy depends on its impact on behavior. Estimating those impacts first requires characterizing current activities and their associated risk levels, and then predicting the effectiveness of risk-reduction strategies. Characterizing the risks from chemical consumer products requires knowledge of both the physical and the behavioral processes that influence exposures. This article presents an integrated approach that combines consumer interviews, users' beliefs and behaviors, and quantitative exposure modeling. This model was demonstrated in the context of consumer exposure to a methylene chloride-based paint stripper, showing how it could be used to evaluate current levels of risk and predict the effectiveness of proposed voluntary risk-reduction strategies.     

Reproductive and Developmental Risks from Ethylene Oxide: A Probabilistic Characterization of Possible Regulatory Thresholds

Ethylene oxide is a gas produced in large quantities in the United States that is used primarily as a chemical intermediate in the production of ethylene glycol, propylene glycol, non-ionic surfactants, ethanolamines, glycol ethers, and other chemicals. It has been well established that ethylene oxide can induce cancer, genetic, reproductive and developmental, and acute health effects in animals. The U.S. Environmental Protection Agency is currently developing both a cancer potency factor and a reference concentration (RfC) for ethylene oxide. This study used the rich database on the reproductive and developmental effects of ethylene oxide to develop a probabilistic characterization of possible regulatory thresholds for ethylene oxide. This analysis was based on the standard regulatory approach for noncancer risk assessment, but involved several innovative elements, such as: (1) the use of advanced statistical methods to account for correlations in developmental outcomes among littermates and allow for simultaneous control of covariates (such as litter size); (2) the application of a probabilistic approach for characterizing the uncertainty in extrapolating the animal results to humans; and (3) the use of a quantitative approach to account for the variation in heterogeneity among the human population. This article presents several classes of results, including: (1) probabilistic characterizations of ED10s for two quantal reproductive outcomes-resorption and fetal death, (2) probabilistic characterizations of one developmental outcome-the dose expected to yield a 5% reduction in fetal (or pup) weight, (3) estimates of the RfCs that would result from using these values in the standard regulatory approach for noncancer risk assessment, and (4) a probabilistic characterization of the level of ethylene oxide exposure that would be expected to yield a 1/1,000 increase in the risk of reproductive or developmental outcomes in exposed human populations.     

Hypothetical Fears and Quantitative Risk Analysis

Hypothetical fears are concepts, not quantities. Their conceptual nature makes impractical conventional quantitative risk analyses (QRA) based on benefit/cost/risk, so they become an unmeasured influence in national decision making. The decision process involves two steps, the Analytic Stage (QRA based) and the Priority Stage (resource allocation competition). This article suggests that a quantitative estimate of the social cost of fear reduction to acceptable levels be used as a surrogate QRA input to the Priority Stage.