我国战略性新兴产业间供应链企业协同创新演化博弈研究

在新兴技术深度交叉融合的新模式下,供应链企业协同创新是加快产业链向高端化延伸的重要途径。本文基于战略性新兴产业的战略性和新兴性,考虑社会效应及市场风险收益因素,构建战略性新兴产业之间供应链企业的演化博弈模型,研究数据库营销成熟度在内的多种因素的影响,通过案例仿真进行验证并分析在市场机制失灵时,政府调控的作用效果。研究结果表明：数据库营销成熟度、协同创新产生的信息流和技术量、技术收益系数和社会效益系数以及损益障碍因子等因素对系统趋于协同创新方向演化具有正向作用;在市场机制失灵时,政府采取成本补贴的激励效果更加高效快速,成果奖励的驱动力更加持久,两种激励手段相结合的方式最优;中等程度的监管力度及低于搭便车收益程度的惩罚并不能保证企业间的公平竞争,高于阈值的惩罚力度才能够有效抑制搭便车收益与前景损益的负向影响,驱动系统向协同创新的方向演化,且惩罚力度越高,系统的收敛速度越快。     

信息通信技术对产业结构优化的影响分析

随着信息通信技术(简称信息技术)在经济高质量发展中作用突显,探索信息技术在产业结构优化中的影响路径,将成为我国经济结构性改革的重要推动力.本研究基于中国30个省(直辖市、自治区)2003-2017年的数据,首先测算了省际信息技术的生产性资本存量;其后,以鲍莫尔效应的发生机制为切入口,建立动态面板数据GMM模型,从理论和经验两个层面揭示信息技术对产业结构的优化路径.结果 发现:(1)总体上,信息技术对各地区的产业结构调整有明显的投资优化效应,但这种投资效应具有分位异质性,如果信息技术的资本规模基数过低,就不能对产业结构优化产生显著影响.(2)信息技术投资对不同产业发展的影响不同.信息技术投资能有效促进第三产业发展,但在第二产业发展中存在投资不足与投资低效问题,阻碍了第二产业发展.(3)伴随不同的工业化阶段,信息技术投资在不同地区的影响存在显著差异.其中,信息技术的投资优化效应在东部地区呈现明显的线性增长特征;在西部地区呈"U型"特征,在中部地区仅仅是工业化后期阶段才呈现正向影响.最后,在此结论基础上提出相关政策建议.     

动态尾部金融网络结构与传染性度量

基于Lasso高维分位数回归模型,本文构建了中国金融系统的尾部网络结构,并定义了总体网络以及行业间、行业内和金融机构间等多层金融网络的尾部风险传染度,解构其传染机制与关联特征,评估各机构双向系统重要性(接收端和发射端)。同时,本文提出了一个最优滚动窗宽选择标准方法,以优化滚动样本技术下的动态网络结构。结果表明,所有层级尾部风险传染效应(总体系统、行业间、行业内和机构间)在经济金融极端困境时期,呈现明显增强及剧烈震荡特征,2015年中国股灾期间尤甚。跨行业传染效应日益严峻,银行与保险间表现出较强关联性,房地产机构与其他金融机构间均表现出较高传染性,跨业监管值得关注。接收与发射最多尾部风险传染的金融机构仍然是银行与证券类机构。系统中超过50%的金融机构倾向于接收风险传染,一旦出现系统性冲击,整个金融系统的稳定性将遭受重创,因此,应加强此类机构应对外界冲击的能力。此外,基于新滚动窗宽选择标准法的动态模型的估计性能明显优于传统方法。研究结论有助于理解中国金融系统的网络结构和传染机制,对宏观审慎监管体系的建立提供了依据。     

A Probabilistic Arsenic Exposure Assessment for Children Who Contact CCA-Treated Playsets and Decks, Part 1: Model Methodology, Variability Results, and Model Evaluation

Concerns have been raised regarding the safety of young children who may contact arsenic residues while playing on and around chromated copper arsenate (CCA)-treated wood playsets and decks. Although CCA registrants voluntarily canceled the production of treated wood for residential use in 2003, the potential for exposure from existing structures and surrounding soil still poses concerns. The EPA's Office of Research and Development developed and applied the probabilistic Stochastic Human Exposure and Dose Simulation model for wood preservatives (SHEDS-Wood) to estimate children's absorbed dose of arsenic from CCA. Skin contact with, and nondietary ingestion of, arsenic in soil and wood residues were considered for the population of children in the United States who frequently contact CCA-treated wood playsets and decks. Model analyses were conducted to assess the range in population estimates and the impact of potential mitigation strategies such as the use of sealants and hand washing after play events. The results show predicted central values for lifetime annual average daily dose values for arsenic ranging from 10(-6) to 10(-5) mg/kg/day, with predicted 95th percentiles on the order of 10(-5) mg/kg/day. There were several orders of magnitude between lower and upper percentiles. Residue ingestion via hand-to-mouth contact was determined to be the most significant exposure route for most scenarios. Results of several alternative scenarios were similar to baseline results, except for the scenario with greatly reduced residue concentrations through hypothetical wood sealant applications; in this scenario, exposures were lower, and the soil ingestion route dominated. SHEDS-Wood estimates are typically consistent with, or within the range of, other CCA exposure models.     

投入产出分析的几种系数矩阵在管理和经济分析中的作用

综合评价投入产出分析的几种系数矩阵在经济指标分析、经济效益分析和经济预测中的作用。提出投资系数矩阵的近似构造法,改进了利润作为目标函数的优化模型和推广了数学增量模型,并通过矩阵变换法从一个投入产出分析系数矩阵生成另一个相似的投入产出分析系数矩阵。     

A Meta-Analysis of Children's Hand-to-Mouth Frequency Data for Estimating Nondietary Ingestion Exposure

Because of their mouthing behaviors, children have a higher potential for exposure to available chemicals through the nondietary ingestion route; thus, frequency of hand-to-mouth activity is an important variable for exposure assessments. Such data are limited and difficult to collect. Few published studies report such information, and the studies that have been conducted used different data collection approaches (e.g., videography versus real-time observation), data analysis and reporting methods, ages of children, locations, and even definitions of "mouthing." For this article, hand-to-mouth frequency data were gathered from 9 available studies representing 429 subjects and more than 2,000 hours of behavior observation. A meta-analysis was conducted to study differences in hand-to-mouth frequency based on study, age group, gender, and location (indoor vs. outdoor), to fit variability and uncertainty distributions that can be used in probabilistic exposure assessments, and to identify any data gaps. Results of this analysis indicate that age and location are important for hand-to-mouth frequency, but study and gender are not. As age increases, both indoor and outdoor hand-to-mouth frequencies decrease. Hand-to-mouth behavior is significantly greater indoors than outdoors. For both indoor and outdoor hand-to-mouth frequencies, interpersonal, and intra-personal variability are approximately 60% and approximately 30%, respectively. The variance difference among different studies is much bigger than its mean, indicating that different studies with different methodologies have similar central values. Weibull distributions best fit the observed data for the different variables considered and are presented in this article by study, age group, and location. Average indoor hand-to-mouth behavior ranged from 6.7 to 28.0 contacts/hour, with the lowest value corresponding to the 6 to <11 year olds and the highest value corresponding to the 3 to <6 month olds. Average outdoor hand-to-mouth frequency ranged from 2.9 to 14.5 contacts/hour, with the lowest value corresponding to the 6 to <11 year olds and the highest value corresponding to the 6 to <12 month olds. The analysis highlights the need for additional hand-to-mouth data for the <3 months, 3 to <6 months, and 3 to <6 year age groups using standardized collection and analysis because of lack of data or high uncertainty in available data. This is the first publication to report Weibull distributions as the best fitting distribution for hand-to-mouth frequency; using the best fitting exposure factor distribution will help improve estimates of exposure. The analyses also represent a first comprehensive effort to fit hand-to-mouth frequency variability and uncertainty distributions by indoor/outdoor location and by age groups, using the new standard set of age groups recommended by the U.S. Environmental Protection Agency for assessing childhood exposures. Thus, the data presented in this article can be used to update the U.S. EPA's Child-Specific Exposure Factors Handbook and to improve estimates of nondietary ingestion in probabilistic exposure modeling.     

互联网媒体企业员工离职行为影响机制研究——基于扎根理论分析

采用扎根理论方法,对某知名互联网媒体企业的47名离职人员进行深度访谈,构建离职行为影响机制模型。研究发现互联网媒体企业员工的离职过程是由行为态度、主观规范、行为控制和离职意向4个因素决定,且在影响程度和形式上有差异。研究为中国互联网媒体企业的员工离职管理提供了启示。     

基于消费者需求与信息搜寻过程的新二维营销战略模型及验证

本项研究从消费者需求与消费者信息搜寻两个维度，将产品市场分为易识常用品市场、易识高档品市场、难识常用品市场、难识高档品市场。基于每一类产品的特征，我们提出不同产品市场的营销战略假设，然后在国内选择五个案例，对我们提出的营销战略假设进行了验证。     

企业技术创新中知识价值实现影响因素的实证研究

本研究目的在于通过实证研究确定企业技术创新中知识价值实现的关键影响因素。通过文献回顾,本文提出了企业技术创新中知识价值实现的衡量标准,构建了知识价值实现影响因素模型,并提出了10条基本假设。作者对120家企业进行了问卷调查,并运用多元回归方法分析了有效数据,结果发现学习型文化、组织距离、群体激励、知识差距和信任水平是企业技术创新中知识价值实现的关键影响因素,其中学习型文化和组织距离对目标变量影响最为显著,最后,对研究结论做了解释。