trust trustworthiness and information sharing in supply chains bridging china and the united states whether and how trust and trustworthiness differ between a collectivist society e g china and an individualistic one e g the united states generates much ongoing scientific debate and bears significant practical values for managing cross country transactions we experimentally investigate how supply chain members countries of origin china versus the united states affect trust trustworthiness and strategic information sharing behavior in a cross country supply chain we consider a two tier supply chain in which the upstream supplier solicits demand forecast information from the retailer to plan production but the retailer has an incentive to manipulate her forecast to ensure abundant supply the levels of trust and trustworthiness in the supply chain and supplier s capability to determine the optimal production quantity affect the efficacy of forecast sharing and the resulting profits we develop an experimental design to disentangle these three aspects and to allow for real time interactions b

assortment planning and inventory decisions under stockout based substitution we present an efficient dynamic programming algorithm to determine the optimal assortment and inventory levels in a single period problem with stockout based substitution in our model total customer demand is random and comprises fixed proportion of customers of different types customer preferences are modeled through the definition of these types each customer type corresponds to a specific preference ordering among products a customer purchases the highest ranked product according to his type if any that is available at the time of his visit to the store stockout based substitution we solve the optimal assortment problem using a dynamic programming formulation we establish structural properties of the value function of the dynamic program that in particular help to characterize multiple local maxima we use the properties of the optima to solve the problem in pseudopolynomial time our algorithm also gives a heuristic for the general case i e when the proportion of customers of each type is random in numerical tests this heuristic performs better and faster than previously known methods especially when the mean demand is large the degree of substitutability is high the population is homogeneous or prices and or costs vary across products

frictionless commerce a comparison of internet and conventional retailers there have been many claims that the internet represents a new nearly frictionless market our research empirically analyzes the characteristics of the internet as a channel for two categories of homogeneous products books and cds using a data set of over 8 500 price observations collected over a period of 15 months we compare pricing behavior at 41 internet and conventional retail outlets we find that prices on the internet are 9 16 lower than prices in conventional outlets depending on whether taxes shipping and shopping costs are included in the price additionally we find that internet retailers price adjustments over time are up to 100 times smaller than conventional retailers price adjustments presumably reflecting lower menu costs in internet channels we also find that levels of price dispersion depend importantly on the measures employed when we compare the prices posted by different internet retailers we find substantial dispersion internet retailer prices differ by an average of 33 for books and 25 for cds however when we weight these prices by proxies for market share we find dispersion is lower in internet channels than in conventional channels reflecting the dominance of certain heavily branded retailers we conclude that while there is lower friction in many dimensions of internet competition branding awareness and trust remain important sources of heterogeneity among internet retailers

walrasian equilibrium with gross substitutes in this paper we study the problem of efficient production and allocation of indivisible objects among a set of consumers we assume that the agents preferences depend on the bundle of objects and the quantity of money they consume furthermore we assume that preferences are quasilinear in money and that agents have a large endowment of money with indivisibilities it is well known that many familiar properties of the utility functions fail to ensure existence in their striking analysis of the matching problem kelso and crawford 5 introduce the gross substitutes gs condition which ensures the non emptiness of the core we propose two new conditions and show that with quasilinearity they are equivalent article id jeth 1999 2531 available online at http www idealibrary com on

endogeneity in brand choice models applications of random utility models to scanner data have been widely presented in marketing for the last 20 years one particular problem with these applications is that they have ignored possible correlations between the independent variables in the deterministic component of utility price promotion etc and the stochastic component or error term in fact marketing mix variables such as price not only affect brand purchasing probabilities but are themselves endogenously set by marketing managers this work tests whether these endogeneity problems are important enough to warrant consideration when estimating random utility models with scanner panel data our results show that not accounting for endogeneity may result in a substantial bias in the parameter estimates

a nonparametric approach to modeling choice with limited data choice models today are ubiquitous across a range of applications in operations and marketing real world implementations of many of these models face the formidable stumbling block of simply identifying the right model of choice to use because models of choice are inherently high dimensional objects the typical approach to dealing with this problem is positing a priori a parametric model that one believes adequately captures choice behavior this approach can be substantially suboptimal in scenarios where one cares about using the choice model learned to make fine grained predictions one must contend with the risks of mis specification and overfitting underfitting thus motivated we visit the following problem for a generic model of consumer choice namely distributions over preference lists and a limited amount of data on how consumers actually make decisions such as marginal information about these distributions how may one predict revenues from offering a particular assortment of choices an outcome of our investigation is a nonparametric approach in which the data automatically select the right choice model for revenue predictions the approach is practical using a data set consisting of automobile sales transaction data from a major u s automaker our method demonstrates a 20 improvement in prediction accuracy over state of the art benchmark models this improvement can translate into a 10 increase in revenues from optimizing the offer set we also address a number of theoretical issues among them a qualitative examination of the choice models implicitly learned by the approach we believe that this paper takes a step toward automating the crucial task of choice model selection this paper was accepted by yossi aviv operations management

an efficient dynamic auction for heterogeneous commodities this paper proposes a new dynamic design for auctioning multiple heterogeneous commodities generalizing earlier work that treated identical objects an auctioneer wishes to allocate one or more units of each of k heterogeneous commodities to n bidders the auctioneer announces a vector of current prices bidders report back quantities demanded at these prices and the auctioneer adjusts the prices units are credited to bidders at the current prices as their opponents demands decline and the process continues until every commodity market clears bidders rather than being required to behave as price takers are permitted to strategically exercise their market power nevertheless with pure private values the proposed auction yields walrasian equilibrium prices an efficient outcome results as from a vickrey clarke groves mechanism but bidders are only required to evaluate their demands along a one dimensional path of prices rather than reporting their utilities over the entire k dimensional consumption set the auction is also more transparent and potentially simpler for bidders to understand and has the advantage of assuring the privacy of the upper portions of bidders demands theoretically the new auction provides a new foundation for convergence to walrasian equilibrium in an exchange economy practically it provides an efficient method for simultaneously auctioning two or more related types of securities for example three month and six month treasury bills it is also potentially useful for auctioning multiple types of communications spectrum for example licenses for paired and unpaired spectrum

dynamic pricing in the presence of strategic consumers and oligopolistic competition we present a dynamic pricing model for oligopolistic firms selling differentiated perishable goods to multiple finite segments of strategic consumers who are aware that pricing is dynamic and may time their purchases accordingly this model encompasses strategic behavior by both firms and consumers in a unified stochastic dynamic game in which each firm s objective is to maximize its total expected revenues and each consumer responds according to a shopping intensity allocation consumer choice model we prove the existence of a unique subgame perfect equilibrium provide equilibrium optimality conditions and prove monotonicity results for special cases the model provides insights about equilibrium price dynamics under different levels of competition asymmetry between firms and multiple market segments with varying properties we demonstrate that strategic behavior by consumers can have serious impacts on revenues if firms ignore that behavior in their dynamic pricing policies moreover ideal equilibrium responses to consumer strategic behavior can recover only a portion of the lost revenues a key conclusion is that firms may benefit more from limiting the information available to consumers than from allowing full information and responding to the resulting strategic behavior in an optimal fashion

optimal and competitive assortments with endogenous pricing under hierarchical consumer choice models this paper studies assortment planning and pricing for a product category with heterogeneous product types from two brands we model consumer choice using the nested multinomial logit framework with two different hierarchical structures a brand primary model in which consumers choose a brand first then a product type in the chosen brand and a type primary model in which consumers choose a product type first then a brand within that product type we consider a centralized regime that finds the optimal solution for the whole category and a decentralized regime that finds a competitive equilibrium between two brands we find that optimal and competitive assortments and prices have quite distinctive properties across different models specifically with the brand primary model both the optimal and the competitive assortments for each brand consist of the most popular product types from the brand with the type primary choice model the optimal and the competitive assortments for each brand may not always consist of the most popular product types of the brand instead the overall assortment in the category consists of a set of most popular product types the price of a product under the centralized regime can be characterized by a sum of a markup that is constant across all products and brands its procurement cost and its marginal operational cost implying a lower price for more popular products the markup may be different for each brand and product type under the decentralized regime implying a higher price for brands with a larger market share these properties of the assortments and prices can be used as effective guidelines for managers to identify and price the best assortments and to rule out nonoptimal assortments our results suggest that to offer the right set of products and prices category and or brand managers should create an assortment planning process that is aligned with the hierarchical choice process consumers commonly follow to make purchasing decisions this paper was accepted by pradeep chintagunta and preyas desai special issue editors this paper was accepted by pradeep chintagunta and preyas desai special issue editors

the package assignment model we study assignment problems where individuals trade packages consisting of several rather than single objects although buyers reservations values are non additive efficient assignments can be formulated as a linear programming problem in which the pricing functions expressing duality may be non linear in the objects constituting the packages the interconnections among the linear programming formulation walrasian equilibrium and the core are established in the single seller auction version a necessary and sufficient condition is given for the vickrey payoff point to be implementable by a pricing equilibrium journal of economic literature classification numbers c62 d44 d51

on ascending vickrey auctions for heterogeneous objects abstract we construct an ascending auction for heterogeneous objects by applying a primal dual algorithm to a linear program that represents the efficient allocation problem for this setting the auction assigns personalized prices to bundles and asks bidders to report their preferred bundles in each round a bidder s prices are increased when he belongs to a minimally undersupplied set of bidders this concept generalizes the notion of overdemanded sets of objects introduced by demange gale and sotomayor for the one to one assignment problem under a submodularity condition the auction implements the vickrey clarke groves outcome we show that this type of condition is somewhat necessary to do so when classifying the ascending auction literature in terms of their underlying algorithms our auction fills a gap in that literature we relate our results to various ascending auctions in the literature

ascending price vickrey auctions for general valuations ascending price auctions typically involve a single price path with buyers paying their final bid price using this traditional definition no ascending price auction can achieve the vickrey clarke groves vcg outcome for general private valuations in the combinatorial auction setting we relax this definition by allowing discounts to buyers from the final price of the auction or alternatively calculating the discounts dynamically during the auction while still maintaining a single price path using a notion called universal competitive equilibrium prices shown to be necessary and sufficient to achieve the vcg outcome using ascending price auctions we define a broad class of ascending price combinatorial auctions in which truthful bidding by buyers is an ex post nash equilibrium any auction in this class achieves the vcg outcome and ex post efficiency for general valuations we define two specific auctions in this class by generalizing two known auctions in the literature 11 24

the english auction with differentiated commodities abstract we study economies with indivisibilities that satisfy the gross substitutes gs condition we define an excess demand set with the property that increasing the prices of all goods in excess demand eventually leads to the smallest walrasian prices this procedure is a generalization of the auction studied by g demange d gale and m j sotomayor polit econ 94 1986 863 872 in our auction truthful revelation of demand is a perfect bayesian equilibrium if the smallest walrasian prices correspond to the vickrey clarke groves payments however no dynamic auction can reveal sufficient information to implement the vickrey mechanism if all gs preferences are allowed journal of economic literature classification numbers d4 d44 d5 d51

symposium on spatial competition and the theory of differentiated markets inclusion of assumptions of the hotelling losch approach spatial price discrimination in the greenhut ohta approach analysis of quality choice spatial approach that typically implies partition of the buyers in sales areas which do not overlap from ebsco

competition based dynamic pricing in online retailing a methodology validated with field experiments a retailer following a competition based dynamic pricing strategy tracks competitors price changes and then must answer the following questions i should we respond ii if so to whom iii how much of a response iv and on which products the answers require unbiased measures of price elasticity as well as accurate estimates of competitor significance and the extent to which consumers compare prices across retailers there are two key challenges to quantify these factors empirically first the endogeneity associated with almost any type of observational data where prices are correlated with demand shocks observable to pricing managers but not to researchers and second the absence of competitor sales information which prevents efficient estimation of a full consumer choice model we address the first issue by conducting a field experiment with randomized prices we resolve the second issue by exploiting the retailer s own and competitors stockouts as a source of variation to the consumer cho

a new and improved design for multiobject iterative auctions in this paper we present a new improved design for multiobject auctions and report on the results of experimental tests of that design we merge the better features of two extant but very different auction processes the simultaneous multiple round smr design used by the fcc to auction the electromagnetic spectrum and the adaptive user selection mechanism ausm of banks et al 1989 allocating uncertain and unresponsive resources an experimental approach rand journal of economics vol 20 no 1 pp 1 25 then by adding one crucial new feature we are able to create a new design the resource allocation design rad auction process which performs better than both our experiments demonstrate that the rad auction achieves higher efficiencies lower bidder losses higher net revenues and faster times to completion without increasing the complexity of a bidder s problem

competitive equilibrium in an exchange economy with indivisibilities abstract we analyze an exchange economy in which i all commodities except money are indivisible ii agents preferences can be described by a reservation value for each bundle of indivisible objects and iii all agents are price takers we obtain a necessary and sufficient condition under which market clearing prices exist implications for market mechanisms are discussed journal of economic literatureclassification numbers d51 c78

multi item auctions a collection of items is to be distributed among several bidders and each bidder is to receive at most one item assuming that the bidders place some monetary value on each of the items it has been shown that there is a unique vector of equilibrium prices that is optimal in a suitable sense for the bidders in this paper we describe two dynamic auction mechanisms one achieves this equilibrium and the other approximates it to any desired degree of accuracy

combinatorial auction design combinatorial auctions have two features that greatly affect their design computational complexity of winner determination and opportunities for cooperation among competitors dealing with these forces trade offs between desirable auction properties such as allocative efficiency revenue maximization low transaction costs fairness failure freeness and scalability computational complexity can be dealt with algorithmically by relegating the computational burden to bidders by maintaining fairness in the face of computational limitations by limiting biddable combinations and by limiting the use of combinatorial bids combinatorial auction designs include single round first price sealed bidding vickrey clarke groves vcg mechanisms uniform and market clearing price auctions and iterative combinatorial auctions combinatorial auction designs must deal with exposure problems threshold problems ways to keep the bidding moving at a reasonable pace avoiding and resolving ties and controlling complexity

side communication yields efficiency of ascending auctions the two items case we analyze an ascending auction with anonymous item prices when there are two items that are substitutes this popular auction format entails increased opportunities for bidders to coordinate bids as the bidding process is longer and since bidders see the other bids and can respond to various signaling this has happened in many real auctions e g in the netherlands 3g telecom auction and in the fcc auctions in the us

supermarket competition the case of every day low pricing every day low pricing edlp strategy has proved to be a successful innovation resulting in higher profits to supermarkets adopting it in competition with promotional pricing promo conventional wisdom attributes this success either to lower costs or to edlp better serving time constrained consumers while discouraging cherry pickers who seek promotions however it is unclear that such cost savings are being fully realized since edlp stores also engage in price promotions also continued existence of promo stores means that costs are not the only factor and they compete effectively without relying just on the cherry pickers furthermore experimental evidence suggests that a supermarket cannot obtain higher profits by merely setting constant low prices leading to the question exactly what makes edlp successful this question is of particular relevance to both academics and practitioners who have been intrigued by the success of this retailing strategy more generally the retailing issues addressed in this paper the economic analysis of competition and the empirical findings should be of interest to the broader community of researchers and managers we investigate the factors contributing to edlp s success by analyzing the competition between supermarkets through a game theoretic analysis of a market consisting of both time constrained consumers and cherry pickers key features of our model are consumers shop and purchase a basket of goods based on price announcements by stores and rational expectations of unannounced prices stores carry more than one good and compete through prices service convenience and appropriate communication strategies and no exogenous cost asymmetries we derive the conditions under which retailers choosing different strategies edlp and promo is a perfect nash equilibrium our analysis shows that the edlp store s offering of constant every day low prices is an equilibrium outcome endogenously determined successful implementation of the edlp strategy involves communication of relative basket prices implying that merely setting constant low prices is not viable we further demonstrate that while time constrained consumers find every day low prices at edlp attractive and cherry pickers the promotions at promo clientele effects are in fact more complicated specifically in equilibrium the promo store offers a higher service level as desired by time constrained consumers and the edlp store a lower service level in keeping with the needs of cherry pickers this choice of service by the two stores results in a cleaner segmentation of the market the higher relative basket price and service at the promo store results in a larger base of time constrained consumers to shop at the promo store and a larger base of cherry pickers to shop at the edlp store even though some cherry pickers continue to visit the promo store to avail of the price specials in this way our results contradict the conventional wisdom on edlp strategy as being mainly geared towards time constrained consumers finally industry profits are higher in an edlp promo equilibrium than when stores adopt identical strategies our analysis and results also offer a more complete characterization of the edlp and promo strategies indeed we show that edlp and promo strategies are positioning strategies rather than merely pricing strategies with different elements price promotions service and communications while the edlp store uses basket prices to attract both segments the promo store uses service and price specials to compete in the time constrained and cherry picking segment respectively given these different approaches of the two stores the communication strategies of the edlp and the promo stores emphasize these differences as well in this way we show as suggested by corstjens and corstjens 1994 that positioning in a retail context involves developing multidimensional strategies appealing to all segments while each element of the strategy may focus on a different consumer segment this is in contrast to the traditional view of segmentation in which different products in a product line for example are designed to appeal to different segments we complete the analysis by examining the data from the trade press and a survey conducted in a major metropolitan area these data while limited in scope support our theoretical results

informational limitations of ascending combinatorial auctions abstract we study the inherent limitations of natural widely used classes of ascending combinatorial auctions specifically we show that ascending combinatorial auctions that do not use both non linear prices and personalized prices cannot achieve social efficiency with general bidder valuations we also show that the loss of efficiency can be severe and that only a diminishing fraction of the social welfare may be captured this justifies the added complexity in the auctions suggested by e g parkes and ungar 2000 29 and ausubel and milgrom 2002 2