On models for the operation of a class of electronic marketplaces

Innovation in information technology and the use of the Internet have enabled electronic marketplaces to become an important mechanism for linking suppliers and customers in a cost-efficient fashion. Previous research has generally focused on the benefits of electronic marketplaces from transaction cost economics and strategic perspectives. Yet very little academic research has addressed how to actually operate such a marketplace. In this paper, after reviewing the status of electronic marketplaces research, we focus on an operational perspective. A model of an electronic marketplace linking customers and suppliers either directly or via an intermediary is given and solved under various scenarios. This model uses a single cost-minimizing objective and the extensions address issues such as (1) a physical presence for the electronic marketplace, which can provide value-added services and preserve anonymity; and (2) sole sourcing or dual sourcing. An additional model explicitly represents the diverse objectives of the multiple players in the market using goal programming. The contribution of this research to practitioners is to offer a cost-effective alternative to current forms of allocating supply and demand. The cost-minimizing and multiple criteria models and extensions in this study make a contribution to research by expanding the horizons of previous studies on the operation of electronic marketplaces.     

BlueLinx can benefit from innovative inventory management methods for commodity forward buys

Commodity prices often fluctuate significantly from one purchasing opportunity to the next. These fluctuations allow firms to benefit from forward buying (buying for future demand in addition to current demand) when prices are low. We propose a combined heuristic to determine the optimal number of future periods a firm should purchase at each ordering opportunity in order to maximize total expected profit when there is uncertainty in future demand and future buying price. We compare our heuristic with existing methods via simulation using real demand data from BlueLinx, a two-stage distributor of building products. The results show that our combined heuristic performs better than any existing methods considering forward buying or safety stock separately. We also compare our heuristic to the optimal inventory management policy by full enumeration for a smaller data set. The proposed heuristic is shown to be close to optimal. This study is the first to decide both the optimal number of future periods to buy for uncertain purchase price and the appropriate purchasing quantity with safety stock for uncertain demand simultaneously. The experience suggests that the proposed combined heuristic is simple and can be very beneficial for any company where forward buying is possible.     

基于相对浮动价和政府补贴的订单农业协调机制研究

考虑政府提供农户生产成本补贴问题,首先构建公司在不同产品质量浮动收购价格模式下,农户、公司和政府的三阶段Stackelberg博弈模型。然后给出最大期望收益目标下农户最优生产规模、公司最优浮动收购价格和社会福利最大化的政府最优补贴率的显式表达式,并分析参数对三方(农户、公司和社会福利)利益的影响。最后进行数值分析,验证了理论结果并进一步得出了相关参数变化的影响。研究结果表明:最优生产规模、农户和公司的收益受政府补贴率、不同质量产品价格浮动幅度、自然条件风险的影响。建议政府给农户提供生产成本补贴以激励农户扩大生产规模,从而提高农户和公司收益;为了协调农户和公司利益,建议在好质量产品比例较高时,差质量产品降价幅度可以大于好质量产品价格增加幅度;而当差质量产品比例较高时,差质量产品降价幅度可以小于好质量产品价格增加幅度。     

考虑消费者网购体验滞后的产品定价研究

随着电子商务技术的发展,网络购物越来越便利。与此同时,网络购物带来的产品体验滞后也导致了消费者对产品的认知不确定性。而这种不确定性正在成为消费者策略性退货行为的主要原因,如消费者同时购买多件具有横向差异的产品,在收到货物后经亲身体验后保留一件而将其他产品退货。本文通过构建Hotelling模型,探讨了企业在考虑此种影响情况下的最优定价策略,分析得出：当消费者的退货成本增加时,企业最优定价也随之增加;消费者对产品的先验效用差异化越小,企业的最优定价也越低。同时发现,若某种产品无消费者单独购买,企业的最优定价会随消费者偏好的增加而增加;而当两种产品均有消费者单独购买且消费者退货成本较大时,企业的最优定价不但不会随消费者偏好的增加而提高,反而会随消费者偏好增加而减少。此外,本文给出了消费者策略性退货行为存在的临界条件,当消费者的退货成本高于这一临界条件时消费者的策略退货行为将消失。     

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.     

Vendor Selection with Bundling*

Product bundling has become increasingly prevalent not only in consumer goods but also in the industrial sector. We study a purchasing problem in which a buyer must obtain necessary numbers of various stock items from a variety of vendors who charge different prices, have limited capacities and different levels of quality, and offer bundled products at discounted prices. We examine relationships among different bundling scenarios and show that the most general scenario is one in which free items are given to the buyer when sufficient quantities are purchased. We develop a mixed integer linear program that finds the purchasing strategy for the buyer that minimizes the total purchase cost. We present computational results which indicate that the problem is very tractable to solve optimally on a personal computer with standard optimization software. Finally, three extensions of the model are discussed.     

Should an OEM Retain Component Procurement when the CM Produces Competing Products?

We consider a large original equipment manufacturer (OEM) who relies on a contract manufacturer (CM) to produce her product. In addition to the OEM's product, the CM also produces for a smaller OEM. Both the larger OEM and the CM can purchase the component from the supplier, but their purchase prices may differ and remain unknown to each other. The main question we address is whether the larger OEM should retain component procurement by purchasing components from the supplier and reselling to the CM (buy–sell), or outsource component procurement by letting the CM purchase directly from the supplier (turnkey). We show that, under buy–sell, the larger OEM's optimal strategy is to resell components at the highest possible component purchase price of the CM (i.e., the street price). By comparing buy–sell and turnkey, we find that a CM with low component price is better off under turnkey, even though under buy–sell he receives more profits through the products sold to the smaller OEM. Furthermore, the larger OEM's preference between buy–sell and turnkey depends on her component price, the volatility of the CM's component price and substitutability between the two products.     

电子商务环境下合作采购效益分析

合作采购是一种重要的企业间电子商务应用模式,成功实施合作采购需要供应链成员的积极参与。本文针对供应商采取的两种批发价定价策略,比较分析了协调成本对买主间合作采购动力及其总体采购成本的影响。其结果表明,只要协调成本较小,买主便具有合作采购动力,且无论供应商采取固定价格策略还是采取数量折扣策略,都存在一个协调成本临界值,当协调成本小于该临界值时,合作采购将同时减少买主与供应商的总体成本;当协调成本大于该临界值时,则总有一方的总体成本在合作采购中增加。     

绿色购买行为演化路径与影响机理分析

绿色消费理念转化为绿色购买行动,消费者需要承担一定的溢价支出。将环保因素引入消费者购买动机函数,考虑消费者的微观异质性、有限理性和环境复杂性,运用计算实验方法,基于情景建模构建消费者绿色购买行为计算实验模型,动态模拟不同情境下消费者参与绿色购买的过程,从宏观方面探索消费者绿色购买行为的演化路径,并从微观方面剖析其影响机理。实验结果显示,虽然价格敏感程度和环保意识水平是消费者绿色购买决策的关键因素,但绿色商品信息占优情境下,"朋友影响"可以显著提高绿色商品市场份额。绿色消费者在自身践行绿色购买的同时,应积极宣传绿色商品信息,这对于促使更多消费者将绿色消费理念转化为绿色购买行动,推动绿色消费市场的健康发展具有重要的现实意义。     

The supplier selection problem with quantity discounts and truckload shipping

To minimize procurement expenditures both purchasing and transportation costs need to be considered. We study a procurement setting in which a company needs to purchase a number of products from a set of suppliers to satisfy customer demand. The suppliers offer total quantity discounts and transportation costs are based on truckload shipping rates. The goal is to select a set of suppliers so as to satisfy product demand at minimal total costs. The resulting optimization problem is strongly NP-hard. We develop integer programming based heuristics to solve the problem. Extensive computational experiments demonstrate the efficacy of the proposed heuristics and provide insight into the impact of instance characteristics on effective procurement strategies.     

救灾供应链采购策略及契约协调机制研究

在救灾物资管理中,购买方在物资采购策略上常陷入两难的境地。从零售商处即时采购物资虽然可以减少库存成本,但物资单价高。从生产商处预先采购物资虽然物资单价低,但会面临风险损失。为解决这一问题,本文将供应链管理引入救灾物资管理体系中,将其视为一个单购买方、单供应方的供应链系统。本研究给出了,带期权契约机制的生产商采购策略中的救灾物资供应链整体期望利润,大于带退货机制的零售商采购策略中的救灾物资供应链总体期望利润的存在条件。在该存在条件满足的情况下,期权契约机制可以协调救灾物资供应链并达到Pareto均衡。此外在考虑了风险水平和风险偏好的情况下,提出了一种基于Nash讨价还价模型的效用函数,以确定能够被供应和购买双方同时接受的期权契约。     

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.

     

Internet Assisted Environmental Purchasing

The use of environmental purchasing as corporate and political instruments to further improve the environmental performance of products is becoming increasingly widespread.Information technology and more specifically the Internet, offers a range of new opportunities to make environmental purchasing operational for both small and large, public and private operations. The benefits of internet-assisted environmental purchasing systems include global system access, no paper handling, ease of operation for procurement staff and a uniform and transparent treatment of suppliers.Tele Danmark Communication (TDC) is Denmark's largest provider of telecommunication services and also operates a chain of stores across Denmark selling telephones and other telecommunication products. Co-funded by the Danish EPA and in collaboration with RAMBØLL Consultants and the Institute for Product Development at the Technical University of Denmark, TDC has developed a prototype internet-assisted environmental purchasing system that covers a wide product assortment of telephones and fax machines. This case exemplifies the particular benefits of Internet systems for environmental purchasing.One role of environmental purchasing is to increase the availability of environmentally friendly products to the end consumer, be it companies, public institutions or private consumers. If published, the information that facilitates environmental purchasing may further assist the end consumer in his or her choice of products. Linking environmental purchasing systems with environmental product declarations may form a powerful marketing tool.     

A Choice‐Based Dynamic Programming Approach for Setting Opaque Prices

Opaque pricing is a form of pricing where certain characteristics of the product or service are hidden from the consumer until after purchase. In essence, opaque selling transforms a differentiated good into a commodity. Opaque pricing has become popular in service pricing as it allows firms to sell their differentiated product at higher prices to regular brand loyal customers while simultaneously selling to non‐brand loyal customers at discounted prices. We use a nested logit model in combination with logistic regression and dynamic programming to illustrate how a service firm can optimally set prices on an opaque sales channel. The choice model allows the characterization of consumer trade‐offs when purchasing opaque products while the dynamic programming approach allows the characterization of the optimal pricing policy as a function of inventory and time remaining. We compare optimal prices and expected revenues when dynamic pricing is restricted to daily price changes. We provide an illustrative example using data from an opaque selling mechanism ( Hotwire.com ) and a Washington DC‐based hotel.     

Comparing products using data envelopment analysis

Using an application of linear programming known as Data Envelopment Analysis (DEA), a method is described to compare products which vary in excellence along a number of dimensions, and for each of which there might be a number of associated “costs”. The method is illustrated by comparing published benchmarks of 37 computer printers. Potential uses of a DEA analysis of products might be: to assist corporate buyers who may need to reconcile a diversity of present and future uses in one standardised purchase; in competitor analysis; in determining unexplored market niches; and as a normative model of product excellence against which product purchasing behaviour could be compared.     

Competition and Coordination in Online Marketplaces

Online marketplaces, such as those operated by Amazon, have seen rapid growth in recent years. These marketplaces serve as an intermediary, matching buyers with sellers, whereas control of the good is left to the seller. In some cases, e.g., the Amazon marketplace system, the firm that owns and manages the marketplace system will also sell competing products through the marketplace system. This creates a new form of channel conflict, which is a focus of this article. We consider a setting in which a marketplace firm operates an online marketplace through which retailers can sell their products directly to consumers. We consider a single retailer, who currently sells its product only through its own website, but who may choose to contract with Amazon to sell its product through the marketplace system. Selling the product through the marketplace expands the available market for the retailer, but comes at some expense, e.g., a fixed participation fee or a revenue sharing requirement. Thus, a key question for the retailer is whether she should choose to sell through the marketplace system, and if so, at what price. We analyze the optimal decisions for both the retailer and the marketplace firm and characterize the system equilibrium.     

多渠道零售环境下消费者渠道选择意愿形成机理研究——产品类别特征的调节作用

传统与网络结合的多渠道正成为零售业的标准模式,多渠道零售环境下,消费者渠道决策发生了根本变化,在不同购买决策过程阶段运用不同渠道的行为日益普遍,但尚未有文献基于搜索信息和产品购买两个阶段,引入产品类别特征对消费者渠道选择意愿形成机理展开研究。运用感知价值理论、信任转移理论构建了消费者搜索意愿和购买意愿形成机理概念模型,分析了渠道属性、渠道内锁定、渠道间协同对消费者搜索与购买意愿的影响及产品搜索性与风险性对其的调节作用,运用联立方程建模并求解发现：渠道属性、渠道内锁定、渠道间协同显著影响消费者搜索意愿和购买意愿;购买高风险搜索产品（如计算机、手机）、低风险搜索产品（如书、文具）、高风险体验产品（如服装、化妆品）、低风险体验产品（如玩具、零食）时,渠道属性、渠道内锁定、渠道间协同对消费者渠道选择意愿的影响存在明显差异;渠道搜索属性如信息有效性、搜索便利性、品种丰富性、社会互动性正向影响消费者搜索意愿,搜索努力负向影响消费者搜索意愿,渠道购买属性如服务质量、购买便利性、享乐性正向影响消费者购买意愿,购买努力、购买风险负向影响消费者购买意愿;传统渠道具有锁定性,网络渠道缺乏锁定性,但购买低风险搜索产品时,网络渠道具有锁定性;购买高风险产品时,传统渠道与网络渠道存在协同性,对于高风险搜索产品,消费者网络渠道搜索意愿正向影响其传统渠道购买意愿,而对于高风险体验产品,还存在消费者传统渠道搜索意愿正向影响其网络渠道购买意愿的协同性,但对于低风险产品,传统渠道与网络渠道缺乏协同性。     

Will More Purchasing Options Benefit Customers?

This paper considers the sale of a seasonal product in the face of strategic customers. At the beginning of the selling season, the retailer announces both the price p_h at which the product will be sold during the selling season and the post‐season clearance price p<p_h for unsold items. We analyze two operating regimes: The “no reservation regime” allows a buyer either to purchase the product at price p_h when he arrives or to enter a lottery to purchase at price p if the product remains unsold. The “reservation regime” offers each buyer one extra option than the no reservation regime: reserve the product for purchase at the clearance price p. If the buyer reserves the product under the reservation regime and if it remains unsold at the end of the selling season, then he is obligated to purchase it at price p. We consider a situation in which heterogeneous customers with probabilistic valuation arrive in accord with a Poisson process. We characterize the rational purchasing behavior wherein each arriving customer is strategic; each customer takes other customers' purchasing behavior into consideration. By considering the Nash equilibrium of this game, we show that strategic customer behavior can render the customer to be worse off and the retailer to be better off under the reservation regime, despite the fact that this regime offers one extra option (reservation) to a customer. Hence, more purchasing options do not necessarily benefit customers.     

多主体参与的绿色技术创新系统均衡及稳定性

构建由政府、企业和消费者组成的绿色技术创新系统演化博弈模型,分析了不同情形下参与主体策略选择对系统均衡策略影响的演化过程,并借助系统动力学实验方法进行了实验模拟论证。研究发现：（1）在绿色技术创新演化博弈系统所有可能的均衡策略中,只存在三个稳定的均衡策略,其中,绿色产品消费的经济收益和绿色技术创新品牌收益是驱动博弈系统向不同稳定均衡策略演进的重要动力。（2）企业绿色技术创新品牌收益和消费者绿色产品消费的经济收益是影响博弈演化系统最终向不同稳定均衡策略演进的主要因素。（3）在均衡状态（1,1,1）和均衡状态（1,0,0）下,通过促进消费者采取购买绿色产品策略对绿色技术创新系统的影响更为显著;在均衡状态（1,1,0）下,促进消费者采取购买绿色产品策略对绿色技术创新系统的影响更为显著,而提高市场规制强度和企业绿色技术创新意愿的影响效果较为微弱。     

基于提前订购策略的供需双方动态博弈模型研究

在两级供应链环境下,相对于传统的即时订购策略,通过以较低批发价提供一个提前订购的机会,给予购买商两次订货机会,那么供应商和购买商的利润可以实现帕累托改进.同时如果供应商在提供提前订购机会的同时收取一个固定费用,则可以进一步优化模型.建立了一个具体的模型,用逆向归纳法计算出了均衡解,并对不同策略下的均衡结果进行了对比分析.