Emerging Market Penetration,Inventory Supply,and Financial Performance

Realizing potential benefits from emerging market penetration requires firms to address inherent supply chain challenges. A major challenge is for firms to manage costly inventories to address demand and supply risks in emerging markets. However, emerging market penetration may offer opportunities for firms to lower inventory levels, reduce costs, and improve operating performance. Using data for 482 manufacturing firms over the 5‐year period, 2003–2007, obtained from the COMPUSTAT Industrial and Segment Databases, this article examines the relationships between emerging market penetration, inventory supply, and financial performance. Our results show that a multinational firm's sales penetration into emerging markets is associated with fewer days of inventory supply and improved financial performance. As emerging market penetration may allow firms to operate with lower inventory supply, the positive effect from emerging market penetration, such as labor cost reductions, may be enhanced due to inventory cost savings.     

Supplier–Buyer Negotiation Games: Equilibrium Conditions and Supply Chain Efficiency

In a decentralized supply chain, supplier–buyer negotiations have a dynamic aspect that requires both players to consider the impact of their decisions on future decisions made by their counterpart. The interaction generally couples strongly the price decision of the supplier and the quantity decision of the buyer. We propose a basic model for a repeated supplier–buyer interaction, during several rounds. In each round, the supplier first quotes a price, and the buyer places an order at that price. We find conditions for existence and uniqueness of a well‐behaved subgame‐perfect equilibrium in the dynamic game. When costs are stationary and there are no holding costs, we identify some demand distributions for which these conditions are met, examine the efficiency of the equilibrium, and show that, as the number of rounds increases, the profits of the supply chain increase towards the supply chain optimum. In contrast, when costs vary over time or holding costs are present, the benefit from multi‐period interactions is reduced and after a finite number of time periods, supply chain profits stay constant even when the number of rounds increases.     

Information‐Sensitive Replenishment when Inventory Records Are Inaccurate

Inspired by recent empirical work on inventory record inaccuracy, we consider a periodic review inventory system with imperfect inventory records and unobserved lost sales. Record inaccuracies are assumed to arrive via an error process that perturbs physical inventory but is unobserved by the inventory manager. The inventory manager maintains a probability distribution around the physical inventory level that he updates based on sales observations using Bayes Theorem. The focus of this study is on understanding, approximating, and evaluating optimal forward‐looking replenishment in this environment. By analyzing one‐ and two‐period versions of the problem, we demonstrate several mechanisms by which the error process and associated record inaccuracy can impact optimal replenishment. Record inaccuracy generally brings an incentive for a myopic manager to increase stock to buffer the added uncertainty. On the other hand, a forward‐looking manager will stock less than a myopic manager, in part to improve information content for future decisions. Using an approximate partially observed dynamic programming policy and associated bound, we numerically corroborate our analytical findings and measure the effectiveness of an intelligent myopic heuristic. We find that the myopic heuristic is likely sufficiently good in practical settings targeting high service levels.     

我国1964～2010年人力资本存量的测算——基于永续盘存法的视角

借鉴永续盘存法思想,综合受教育年限法与学历权重法,对1964～2010年我国劳动力和14岁以上人口的人力资本存量进行测算。结果显示,1964年以来我国以上两类人力资本存量均呈现逐年增加的态势,且劳动力的人力资本存量增速更快;但直至2010年二者的人均受教育年限均低于义务教育所要求的9年。     

交叉销售下基于支持向量聚类的数据驱动多产品库存鲁棒优化模型

针对单周期环境下考虑交叉销售的多产品库存决策问题,在市场需求不确定条件下,建立了带有预算约束的交叉销售多产品库存鲁棒优化模型。针对不确定市场需求,采用支持向量聚类(SVC)方法构建了满足一定置信水平的数据驱动不确定集。进一步,运用拉格朗日对偶方法将所建模型等价转化为易于求解的线性规划问题。最后,通过数值计算对比分析了SVC不确定集下及传统不确定集下的零售商利润绩效,并评估了SVC数据驱动鲁棒优化方法导致的绩效损失,进而分析了预算及交叉销售系数对零售商利润绩效的影响。结果表明,SVC数据驱动鲁棒优化方法具有良好的鲁棒性,能够有效抑制需求不确定性对从事多产品销售的零售商利润绩效的影响。特别地,需求分布信息的缺失虽然会给零售商带来一定的绩效损失,但损失值很小,表明文中提出的基于SVC的数据驱动鲁棒优化方法可以为管理者在需求不确定性环境下制定库存策略提供有效决策借鉴。     

基于内生折旧率的中国行业层面资本存量估计

资本存量是宏观经济研究及政策制定中一个极其重要的变量,而在测算资本存量的过程中,核心变量折旧率的确定对结果具有关键性的影响。相比选取某一折旧率固定值,通过生产函数法对中国1981—2011年33个行业的固定资本折旧率进行测算的方法更加科学,更能反映中国现实的行业特征。在测算的折旧率结果的基础上,进一步运用永续盘存法进行各年份各行业资本存量的估计。结果表明,从横向上看,各行业的建筑资本存量及设备资本存量都存在着较大的行业差异,建筑存量尤为突出;从纵向上看,各行业的两类资本存量都具有明显的递增发展趋势,这与中国当前的经济形势以及行业特征大致吻合,在一定程度上能反映中国的宏观经济现状及行业结构特征。     

一类考虑反 S型概率权重的供货中断库存模型

在连续盘点库存系统中应用零点订货库存（ZIO）策略,假设供应商工作和中断的持续时间分别服从独立的指数分布。首先,引入反S 型权重函数刻画风险厌恶型决策者主观高估补货点供应商处于中断的小概率关键事件的行为偏好。其次,利用两个状态连续时间Markov 链和更新报酬定理构建了长程平均成本模型,证明了成本函数的单峰性,对比讨论了结合数值算例与风险中性模型结论。最后,设计了近似条件得出最优订货量的解析表达式及成本的近似误差上界,配合基准集和随机数据集分别计算了160 组和 10 000 组数值实验样本,验证了近似方法的有效性。     

基于库存价值变化的应急物资库存控制模型研究

应急物资储备是实施应急救援、提高反应速度的基础,是我国应急管理建设的重要内容。从库存价值变化的角度出发,建立应急物资库存成本最小化和期望效益最大化的动态储备模型,以实现低库存成本与高应急保障水平之间的动态平衡。该模型考虑了应急物资库存可能发生贬值或增值情况,以"先进先出"原则研究了库存物资周期性消耗和补给的过程,实现了同等保障水平下应急物资的社会效益,同时,可平衡储备物资在市场中的供需关系。     

基于需求更新的民航收入管理动态存量控制模型

本文对民航收入管理存量控制研究中具有里程碑意义的EMSR(Expected Marginal Seat Revenue)模型进行了评述,分析其存在的缺陷,提出将销售过程中获取的最新销售信息与需求的历史先验分布相结合,运用二维正态分布下的贝叶斯模型对需求分布进行更新,并将综合考虑新的需求预测、No-Show和取消订票等因素得到的新的需求限制与座位总数C相比较,给出更为通用的、市场反应更为灵敏的民航收入管理动态存量控制模型。     

Changing risk preferences in supply chain inventory decisions

The risk preferences of managers may cause their inventory ordering decisions to deviate from the optimal policy. Past studies in operations management have produced mixed results. This study examines this proposition using decision data collected from a supply chain experiment. This article finds that changing the risk preferences of managers with respect to demand changes and supplier failures is a significant behavioural factor in explaining deviations in ordering decisions. This result provides an additional behavioural cause in explaining the bullwhip effect in supply chains. It also provides insights on the challenges for reducing the bullwhip effect in supply chains.