具有线性交易成本的耐用性设备在线租赁策略分析

在设备寿命周期内,购买和使用结束后出售旧设备需要支付交易成本,交易成本与设备价格具有线性关系。分析显示:对于具有线性交易成本的耐用性设备在线租赁问题,如果不考虑在设备使用结束后出售旧设备的残值以降低成本,从租赁模式转换到购买模式的在线策略的转换时机,总是晚于考虑在设备使用结束后出售旧设备的在线策略;如果不考虑购买和使用后出售的交易成本,在线策略名义上的竞争比小于实际竞争比。     

Obtaining the optimal fleet mix: A case study about towing tractors at airports

Planes do not have a reverse gear. Hence, they need to be towed by tractors when leaving the gate. Towing tractors differ with respect to investment as well as variable costs and plane type compatibility. We propose a model which addresses the problem of a cost minimal fleet composition to support towing service providers in their strategic investment decisions. The model takes into account a maximum lifetime, a minimum duration of use, an overhaul option and a sell option. In a case study with a major European airport (our cooperating airport) we generate a multi-period fleet investment schedule. Furthermore, we introduce a 4-step approach for demand aggregation based on flight schedule information. We analyze the impact of demand variation, flight schedule disruptions and cost structure on the optimal buy, overhaul and sell policy. The scenario analyses demonstrate the robustness of the investment schedule with respect to these factors. Ignoring the existing fleet, a green field scenario reveals saving potentials of more than 5% when applying this model.     

Idiosyncratic Shocks and the Role of Nonconvexities in Plant and Aggregate Investment Dynamics

We study a model of lumpy investment wherein establishments face persistent shocks to common and plant‐specific productivity, and nonconvex adjustment costs lead them to pursue generalized (S, s) investment rules. We allow persistent heterogeneity in both capital and total factor productivity alongside low‐level investments exempt from adjustment costs to develop the first model consistent with the cross‐sectional distribution of establishment investment rates. Examining the implications of lumpy investment for aggregate dynamics in this setting, we find that they remain substantial when factor supply considerations are ignored, but are quantitatively irrelevant in general equilibrium. The substantial implications of general equilibrium extend beyond the dynamics of aggregate series. While the presence of idiosyncratic shocks makes the time‐averaged distribution of plant‐level investment rates largely invariant to market‐clearing movements in real wages and interest rates, we show that the dynamics of plants' investments differ sharply in their presence. Thus, model‐based estimations of capital adjustment costs involving panel data may be quite sensitive to the assumption about equilibrium. Our analysis also offers new insights about how nonconvex adjustment costs influence investment at the plant. When establishments face idiosyncratic productivity shocks consistent with existing estimates, we find that nonconvex costs do not cause lumpy investments, but act to eliminate them.     

Optimal Per‐Use Rentals and Sales of Durable Products and Their Distinct Roles in Price Discrimination

We consider a setting in which consumers experience distinct instances of need for a durable product at random intervals. Each instance of need is associated with a random utility and the consumers are differentiated according to the frequency with which they experience such instances of need. We use our model of consumer utility to characterize the firm's optimal strategy of whether to sell, rent, or do a combination of both in terms of the transaction costs and consumers' usage characteristics. We find that the two modes of operation serve different roles in allowing the firm to price discriminate. While sales allow the firm to discriminate among consumers of different usage frequencies, rentals allow it to discriminate according to consumers' realized valuations. Consequently, even when transaction costs are negligible, it is often optimal for the firm to simultaneously rent and sell its product. In addition, we find that although sales and rentals are substitutes and that the offering of sales weakly increases rental prices, it is possible that the introduction of rentals to a pure selling operation can either increase or decrease the optimal sales prices.     

拥有自有品牌零售商的平台开放策略研究

随着电子商务的快速发展，零售商之间竞争加剧，自有品牌战略成为零售商获取竞争优势的关键。研究拥有自有品牌零售商的平台开放策略，通过对比零售商不开放平台和开放平台下的均衡利润，给出零售商平台开放策略选择条件，并分析产品之间价格影响系数、固定成本和潜在需求差异系数对零售商平台开放策略选择的影响，最后结合数值分析和京东自有品牌的发展现状验证了本文的主要研究结论。研究发现：第一，随着固定成本的增加，佣金费率逐渐减少，随着潜在需求差异系数的增加，佣金费率逐渐增加；第二，当产品之间的价格影响系数较小（较大）时，平台开放（不开放）是零售商的最优选择；第三，当固定成本较小（较大）时，平台开放（不开放）是零售商的最优选择；第四，当潜在需求差异系数较小（较大）时，平台开放（不开放）是零售商的最优选择。     

Vendor Selection with Bundling: A Comment*

In a recent article by Rosenthal, Zydiak, and Chaudhry (1995), a mixed integer linear programming model was introduced to solve the vendor selection problem for the case in which the vendor can sell items individually or as part of a bundle. Each vendor offered only one type of bundle, and the buyer could purchase at most one bundle per vendor. The model employed n(m+ 1) binary variables, where n is the number of vendors and m is the number of products they sell. The existing model can lead to a purchasing paradox: it may force the buyer to pay more to receive less. We suggest a reformulation of the same problem that (i) eliminates this paradox and reveals a more cost-effective purchasing strategy; (ii) uses only n integer variables and significantly reduces the computational workload; and (iii) permits the buyer to purchase more than one bundle per vendor.     

电商平台自营和制造商直销的多渠道竞争策略研究

近年来电商平台自营产品和制造商开辟直销渠道已非常普遍。电商平台的自营行为，必然会产生与制造商销售渠道（通过平台销售的渠道或直销渠道）的竞争问题；制造商的直销行为，必然会产生与电商平台自营渠道的竞争问题。这种全新的渠道竞争行为非常值得研究，也是本文的研究核心。因此，运用博弈论的相关原理，本文得出并分析了不同情况下电商平台和制造商的博弈均衡策略。研究表明，当直销成本较低时，最终博弈均衡策略为：电商平台自营，制造商同时经营两条渠道；此时如果制造商的两条销售渠道竞争力都强，双方陷入囚徒困境，否则，电商平台利润改善，制造商利润降低。当直销成本适中时，最终博弈均衡策略为：电商平台自营，制造商只直销；此时，如果制造商的两条销售渠道竞争力都强、或平台渠道竞争力适中且直销渠道竞争力强，双方陷入囚徒困境，否则，电商平台利润改善，制造商利润降低。当直销成本较高时，若直销渠道竞争力强，双方将陷入斗鸡博弈。否则，最终博弈均衡策略为：电商平台自营，制造商不直销；此时，电商平台利润会改善，制造商利润会下降。     

Die Entscheidung über den Verkauf von Wertpapieren unter der Abgeltungssteuer und auf Basis subjektiver Erwartungen

Since January 1, 2009 realized capital gains on securities are taxable in Germany regardless of the investor’s holding period. This paper examines when a rational investor should optimally sell a security in the presence of capital gains taxes. Besides taxes, our analysis considers the relevance of investor’s subjective expectations about future market prices of the security. The results suggest that investors should base divestment decisions primarily on their expectations. To realize losses or to avoid the realization of taxable gains (i.e. the lock-in-effect) is of minor importance for the optimal divestment strategy. This result becomes even more pronounced when transaction costs and limitations to save taxes by realizing losses are considered. Numerical calculations illustrate the results of our analysis.     

带学习效应的双渠道供应链库存策略研究

针对具有学习行为的双渠道供应链问题,本文研究了两种分销渠道并存下的最优库存策略。有限计划期内,分销商通过传统销售和在线销售来满足下游顾客的需求。两种分销渠道下的销售单价为时变不减线性函数,当系统中各周期的生产订购固定成本以一定的概率具有学习效应行为时,分别建立了非变质产品生产存贮问题的混合整数约束优化模型以及易变质产品存贮问题的无约束混合整数优化模型,所建立模型的目标为极大化分销商总利润函数。对于这两类模型,通过分析其最优解的性质,利用将生产订购次数松弛为连续变量的技巧证明了最优解存在的唯一性。给出了最优策略的求解方法并比较了两类模型最优利润函数值的大小。最后通过数值算例对上述模型进行了验证,数值结果表明当供应链系统中存在学习效应行为时,该系统能够获得更多的利润。     

消费者短视和以旧换新情形下设计架构与定价策略研究

耐用品的耐用性会抑制了新一代耐用品的销售,企业通常会采用以旧换新政策来激励新一代耐用品的销售。企业有两种产品设计架构策略:一体化架构策略与模块化架构策略,同时企业也有两种定价策略:静态定价策略和动态定价策略。在这种情况下,企业该如何确定产品设计架构和定价策略?在假定两期内消费者是短视情形下,论文建立了消费者与企业博弈模型分析和比较了三种情况。研究发现,无论是静态定价还是动态定价,无论是模块化架构还是一体化架构,购买了第一代产品的消费者都会整体更换成第二代产品;随着第二代核心系统的质量提升,以旧换新促使企业产品架构选择从一体化架构转变为选择模块化架构;当采用动态定价、第二代核心系统质量提升适中和折扣因子高时,企业会选择模块化架构;当企业采用模块化架构时,以旧换新政策会降低模块化产品第二代核心子系统和基础子系统之间的兼容性;如果两代产品之间的质量差距比较大,企业将会选择动态定价策略,反之会选择静态定价策略。     

Advance Selling in the Presence of Speculators and Forward‐Looking Consumers

This article examines the pricing policy of a monopolist seller who may sell in advance of consumption in a market that comprises of myopic consumers, forward‐looking consumers, and speculators. The latter group has no consumption value for the goods and is in the market with the sole objective of making a profit by reselling the purchased goods shortly after. Consumers, although homogeneous in terms of their valuations, are different with respect to their perspectives. We show that in an “upward” market where the expected valuation increases over time, the optimal pricing policy is an ex ante “static” one where the seller “prices into the future” and prices the myopic consumers out of the advance market. However, in a “downward” market where the expected valuation decreases over time, the seller adopts a dynamic pricing strategy except for the case when higher initial sales can trigger more demand subsequently and when the downward trend is not too high. In this case, the seller prefers an ex ante “static” pricing strategy and deliberately prices lower initially to sell to speculators. We identify the conditions under which the seller benefits from the existence of speculators in the market. Moreover, although the presence of entry costs is ineffective as an entry deterrence, we determine the conditions under which exit costs can rein in speculative purchase.     

A sustainable second-generation biodiesel supply chain network design problem under risk

This paper presents a multi-objective possibilistic programming model to design a second-generation biodiesel supply chain network under risk. The proposed model minimizes the total costs of biodiesel supply chain from feedstock supply centers to customer centers besides minimizing the environmental impact (EI) of all involved processes under a well-to-wheel perspective. Non-edible feedstocks are considered for biodiesel production. Variable cultivation cost of non-edible feedstock is assumed to be non-linear and dependent upon the amount of cultivated area. New formulation of possibilistic programming method is developed which is able to minimize the total mean and risk values of problems with possibilistic-based uncertainty. To solve the proposed multi-objective model, a hybrid solution approach based on flexible lexicographic and augmented ɛ-constraint methods is proposed which is capable to find appropriate efficient solutions from the Pareto-optimal set. The performance of the proposed possibilistic programming method as well as the developed solution approach are evaluated and validated through conducting a real case study in Iran. The outcome of this study demonstrates that high investment cost is required for improving the environmental impact and risk of sustainable biodiesel supply chain network design under risk. Decision maker preferences are required for suitable trade-off among total costs, risk values and environmental impact.     

Optimal Digital Rights Management with Uncertain Piracy

Many firms that sell digital copies of copyrighted materials online face a common dilemma: the use of digital rights management (DRM) to impede pirates can impose restrictions on legitimate use. We introduce a two‐period model in which the use of DRM in the first period affects the probability that a consumer finds a pirated copy in the second period; the threat of legal action reduces consumers’ consumption of pirated copies; and firms choose whether to sell, and at what prices, either strongly or weakly DRM‐protected products, or both. Furthermore, we incorporate the role of uncertainty concerning future levels of piracy. Using a two‐period model with uncertainty, we investigate a firm's optimal DRM strategies and present the optimal pricing strategy as well as product launch strategy under different market conditions. We find that one important characteristic of the optimal strategy is that it is optimal to maintain the same product line configuration strategy for both periods. We also characterize the conditions under which each strategy is optimal.     

Modeling and optimizing an agro-supply chain considering different quality grades and storage systems for fresh products: a Benders decomposition solution approach

This paper proposes a mathematical model in the context of agro-supply chain management, considering specific characteristics of agro-products to assist purchase, storage, and transportation decisions. In addition, a new method for determining the required quality score of different types of products is proposed based on their loss factors and purchasing costs. The model aims to minimize total cost imposed by purchasing fresh products, opening warehouses, holding inventories, operational activities, and transportation. Two sets of examples, including small and medium-sized problems, are implemented by general algebraic modeling language (GAMS) software to evaluate the model. Then, Benders decomposition (BD) algorithm is applied to tackle the complexity of solving large-sized instances. The results of both GAMS and BD are compared in terms of objective function values and computational time to demonstrate the efficiency of the BD algorithm. Finally, the model is applied in a real case study involving an apple supply chain to obtain managerial insights.

     

Role of Random Capacity Risk and the Retailer in Decentralized Supply Chains with Competing Suppliers

This research considers a supply chain under the following conditions: (i) two heterogeneous suppliers are in competition, (ii) supply capacity is random and pricing is endogenous, (iii) consumer demand, with and without an intermediate retailer, is price dependent. Specifically, we examine how uncertainty in supply capacity affects optimal ordering and pricing decisions, supplier and retailer profits, and the incentives to reduce such uncertainty. When two suppliers sell through a monopolistic retailer, supply uncertainty not only affects the retailer's diversification strategy for replenishment, but also changes the suppliers’ wholesale price competition and the incentive for reducing capacity uncertainty. In this dual‐sourcing model, we show that the benefit of reducing capacity uncertainty depends on the cost heterogeneity between the suppliers. In addition, we show that a supplier does not necessarily benefit from capacity variability reduction. We contrast this incentive misalignment with findings from the single‐supplier case and a supplier‐duopoly case where both suppliers sell directly to market without the monopolistic retailer. In the latter single‐supplier and duopoly cases, we prove that the unreliable supplier always benefits from reducing capacity variability. These results highlight the role of the retailer's diversification strategy in distorting a supplier's incentive for reducing capacity uncertainty under supplier price competition.     

确定需求下VMI-TPL分销供应链集成库存策略研究

针对VMI在实施中存在的问题,本文将TPL引入VMI,构建了确定需求下,由制造商、TPL和多零售商构成,考虑原材料、产成品的VMI-TPL供应链集成库存模型,并给出了最优生产策略和库存策略.在此基础上,文章进一步讨论了产需比等变量对供应链成本的影响,并比较分析了引入TPL前后VMI的最优策略.研究表明:引入TPL能有效降低供应链平均总成本,避免制造商高库存成本和高运营风险;制造商的产需比(p/d)对TPL引入后的效果影响很大,产需比越大,引入TPL的效果越好.     

非平稳需求下考虑碳配额的供应链选址-库存模型与算法研究

针对非平稳需求下考虑碳配额的多期、多需求情景的三级供应链选址-库存问题，构建了库存策略（t，s，S）下供应链运营期望收益最大化的两阶段选址-库存随机优化模型，依据供应链企业不同着眼点下的决策流程，提出了一种三步骤的分层级启发式算法，该算法包含了选址导向和需求导向的两种子问题序贯求解模式。数值算例验证了在不同问题规模及需求类型下算法求解的有效性，同时分析了供应链网络设计、各成本占比和运营收益对不同供应链成本结构、需求不确定性与碳配额的敏感性，并给出了管理上的启示。     

Production stage allocation problem in large corporations

This paper studies a strategic-level decision problem on assigning production stages to geographically distributed subsidiaries in a large corporation so as to minimize the fixed cost and the expected value of the production/transportation costs under stochastic demands of customers. The influence of the economies and diseconomies of scale on unit production cost is considered. A nonlinear mixed integer programming model is designed for this problem. A local branching based solution method and a particle swarm optimization based solution method are developed for solving the model. Computational tests on real world data of Shanghai Volkswagen Auto Corp. are conducted. The results show that the proposed model can save about 2.5% of its revenue by comparing with the current decisions.     

“Do as I Do and Not as I Say”: Exploring Price‐Oriented Maverick Buying During Supplier Selection

This article empirically examines the occurrence of price‐oriented maverick buying (MB) during supplier selection, in a direct purchasing process context. Drawing on agency theory, maverick buying, and total cost of ownership (TCO) literature, the statistically significant existence of price‐oriented MB is investigated and the purchasing manager (PM)‐related factors that influence such noncompliant behavior are determined. A discrete choice experiment is designed to simulate a TCO‐based supplier selection process in which an established purchasing framework agreement stipulates PMs not necessarily be price‐oriented (i.e., select suppliers primarily based on lowest price), and then models PM choice behavior in the supplier selection process (SSP), utilizing a conditional logit model (CLM) to determine PM compliance to the established purchasing framework agreement and identify if price‐oriented MB exists. Statistical tests utilizing comprehensive primary and secondary data are then conducted to determine if correlational relationships exist between PM‐related factors and PM price‐orientation. Results indicate that three PM‐related factors bear a significant correlational relationship to PM price‐orientation.     

Economic Costs of Misinforming About Risk: The EDB Scare and the Media

This study reports results of an analysis of consumer responses to news reports of grain-product contamination by the pesticide ethylene dibromide (EDB). The results demonstrate that it is possible to quantify market disruption related to the dissemination of risk information. Implications include the need for increased awareness among risk managers that public perceptions, regardless of their objective accuracy, can induce real economic costs. Such costs should be considered in designing regulatory and information policies.