Let's Call it Quits: Break‐Even Effects in the Decision to Stop Taking Risks

“Chasing” behavior, whereby individuals, driven by a desire to break even, continue a risky activity (RA) despite incurring large losses, is a commonly observed phenomenon. We examine whether the desire to break even plays a wider role in decisions to stop engaging in financially motivated RA in a naturalistic setting. We test hypotheses, motivated by this research question, using a large data set: 707,152 transactions of 5,379 individual financial market spread traders between September 2004 and April 2013. The results indicate strong effects of changes in wealth around the break‐even point on the decision to cease an RA. An important mediating factor was the individual's historical long‐term performance. Those with a more profitable trading history were less affected by a fall in cash balance below the break‐even point compared to those who had been less profitable. We observe that break‐even points play an important role in the decision of nonpathological risk takers to stop RAs. It is possible, therefore, that these nonpathological cognitive processes, when occurring in extrema, may result in pathological gambling behavior such as “chasing.” Our data set focuses on RAs in financial markets and, consequently, we discuss the implications for institutions and regulators in the effective management of risk taking in markets. We also suggest that there may be a need to consider carefully the nature and role of “break‐even points” associated with a broader range of nonfinancially‐focused risk‐taking activities, such as smoking and substance abuse.     

面向多样化需求的M RO 服务资源配置模型与算法

针对大型复杂企业维修任务集的多服务需求点和多样化需求特征,基于服务需求视角,定义一类多服务需求点下的MRO服务资源配置问题,建立以MRO服务提供商整体服务成本为优化目标,同时考虑资源紧张度、信任度和多服务需求点不同工期要求的问题模型;针对模型中的关键参数（即服务成本和资源紧张度）的特征进行分析,并给出相应的度量方法;在此基础上,设计改进的模拟植物生长算法实现求解,算法通过启发式获得初始可行解,并进行敏感性分析。研究结果表明, MRO服务资源配置模型和算法是可行和有效的,服务成本的波动、信任度和资源紧张度的变化对于资源配置结果均有影响,模型能够有效提高维修服务成本的估算能力,同时能够保持MRO服务提供商资源配置的稳定性。     

基于提前期的多阶通用件库存模型

针对单个企业内部应用通用件的环境,在假定一个多阶生产系统的基础上,对应用通用件的库存量水平及其成本进行了分析,建立了多阶通用件库存模型,提出通过对采用通用件和不采用通用件的成本差异的比较,来决策多阶生产系统中在哪一阶工序采用通用件,并求解出每一阶工序优化的基本库存水平。     

对学习历史事件法的一种改进

依据组织学习理论,对学习历史事件法进行了改进。由于企业的经验知识不完全等同于隐性知识,学习历史事件法同样不能直接应用于隐性知识的转化,为此,提出了适合隐性知识转化的改进型学习历史事件法。改进充分考虑了隐性知识的特征,并专门对隐性知识和经验知识进行了区分。同时,改进的学习历史事件法充分考虑了企业应用的可操作性,保留了量表的形式。最后,将该方法应用于MIS项目开发中,对新改进的量表进行了定量解析。     

招标与投标竞争系统决策模型及其应用

招投标理论所研究的首要问题是投标商的投标策略问题,其中最优报价尤为重要。本文利用两种方法-解析法和利润法,解决了独立投标中的最优报价问题。     

我国西南民族地区与东部地区农村发展差距研究

比较分析我国西南民族地区与东部地区农村发展差距及原因,提出缩小农村发展差距的对策。     

摩托车市场需求预测模型研究

本文通过对摩托车市场系统分析,确立了相关影响因素,建立了回归预测模型和系统动力学模型,依此对我国摩托车未来需求量进行了预测.     

On inference for Kendall's τ within a longitudinal data setting

Kendall's τ is a non-parametric measure of correlation based on ranks and is used in a wide range of research disciplines. Although methods are available for making inference about Kendall's τ, none has been extended to modeling multiple Kendall's τs arising in longitudinal data analysis. Compounding this problem is the pervasive issue of missing data in such study designs. In this article, we develop a novel approach to provide inference about Kendall's τ within a longitudinal study setting under both complete and missing data. The proposed approach is illustrated with simulated data and applied to an HIV prevention study.     

SAM平衡的SG-RAS与SG-CE方法

随机cross entropy(Robinson et al.,2001)方法是目前用于平衡社会核算矩阵的最主流方法,本文综合其与GRAS(Lenzen et al.,2007)方法的思想,扩展提出了SG-CE(stochastic generalized CE)与SG-RAS方法,避免了原始CE方法在平衡SAM时需要对负值元素进行预处理的步骤,试图改进由此引致的缺陷并提高平衡SAM质量。在此基础上,本文运用SG-RAS、SG-CE、CE以及国内常用的余量法对中国2007年SAM进行了平衡,实证结果的对比表明:在平衡系数SAM时,SG-RAS优势非常明显;而平衡流量SAM时,除SG-RAS之外,余量法也具较好表现;但无论是平衡系数还是流量SAM,SG-CE的效果只能说差强人意,原始CE方法更差。     

Density Estimation in Several Populations With Uncertain Population Membership

We devise methods to estimate probability density functions of several populations using observations with uncertain population membership, meaning from which population an observation comes is unknown. The probability of an observation being sampled from any given population can be calculated. We develop general estimation procedures and bandwidth selection methods for our setting. We establish large-sample properties and study finite-sample performance using simulation studies. We illustrate our methods with data from a nutrition study.