securitization of taxes implicit in payg pensions to preserve solvency a pay as you go payg pension system needs to adjust contribution rates and pension promises over time currently it is not possible to hedge in the financial market against politically determined uncertainty as regards these parameters i consider a policy reform whereby property rights are established on the implicit lifetime tax levied by payg finance and are assigned to the pension institution these property rights are well defined if the reform also features rule based allocation of aggregate risk in the form of defined contribution or defined benefit schemes i show that a payg pension system may indeed be instantly restructured so as to minimize political risk and allow financial market diversification of risk a side benefit is securitization of human capital flows which are not traded in existing financial markets the new securities if traded in appropriately competitive financial markets are complementary to the notional account reforms of the 1990s however fiscal instability can increase if securitization is implemented in the absence of initial solvency and credible adoption of rule based methods to allocate aggregate risk salvador valdes prieto

make to order or make to stock model and application some firms make all their products to order while others make them to stock there are a number of firms that maintain a middle ground where some items are made to stock and others are made to order this paper was motivated by a consumer product company faced with the decision about which items to make to stock and which ones to make to order and the inventory and production policy for the make to stock items the production environment is characterized by multiple items setup times between the production of consecutive items limited capacity and congestion effects in such an environment making an item to order reduces inventory costs for that item but might increase the lot size and inventory costs for the items made to stock also lead times increase because of congestion effects resulting in higher safety stocks for make to stock items and lower service levels for make to order items thus leading to a complex trade off we develop a nonlinear integer programming formulation of the problem we present an efficient heuristic to solve the problem which was motivated by key results for a special case of the problem without congestion effects that can be solved optimally we also develop a lower bound to evaluate the performance of the heuristic a computational study indicates that the heuristic performs well we discuss the application of the model in a large firm and the resulting insights we also provide insights into the impact of various problem parameters on the make to order versus make to stock decisions using a computational study in particular we find that the average number of setups of an item selected for make to stock production is always less than half the average number of setups of the item if it were to be made to order also factors other than an item s demand such as its setup time processing time and unit holding cost impact the make to order versus make to stock decision

estimation of consumer demand with stock out based substitution an application to vending machine products the occurrence of temporary stock outs at retail is common in frequently purchased product categories available empirical evidence suggests that when faced with stock outs consumers are often willing to buy substitute items an important implication of this consumer behavior is that observed sales of an item no longer provide a good measure of its core demand rate sales of items that stock out are right censored while sales of other items are inflated because of substitutions knowledge of the true demand rates and substitution rates is important for the retailer for a variety of category management decisions such as the ideal assortment to carry how much to stock of each item and how often to replenish the stock the estimated substitution rates can also be used to infer patterns of competition between items in the category in this paper we propose methods to estimate demand rates and substitution rates in such contexts we develop a model of customer arrivals and choice between goods that explicitly allows for possible product substitution and lost sales when a customer faces a stock out the model is developed in the context of retail vending an industry that accounts for a sizable part of the retail sales of many consumer products we consider the information set available from two kinds of inventory tracking systems in the best case scenario of a perpetual inventory system in which times of stock out occurrence and cumulative sales of all goods up to these times are observed we derive maximum likelihood estimates mles of the demand parameters and show that they are especially simple and intuitive however state of the art inventory systems in retail vend ing provide only periodic data i e data in which times of stock out occurrence are unobserved or missing for these data we show how the expectation maximization em algorithm can be employed to obtain the mles of the demand parameters by treating the stock out times as missing data we show an application of the model to daily sales and stocking data pooled across multiple beverage vending machines in a midwestern u s city the vending machines in the application carry identical assortments of six brands since the number of parameters to be estimated is too large given the available data we discuss possible restrictions of the consumer choice model to accomplish the estimation our results indicate that demand rates estimated naively by using observed sales rates are biased even for items that have very few occurrences of stock outs we also find significant differences among the substitution rates of the six brands the methods proposed in our paper can be modified to apply to many nonvending retail settings in which consumer choices are observed not their preferences and choices are constrained because of unavailability of items in the choice set one such context is in store grocery retailing where similar issues of information availability arise in this context an important issue that would need to be dealt with is changes in the retail environment caused by retail promotions

integrated multi item production inventory systems abstract we study an integrated multi item production inventory system with stochastic demands and capacitated production the problem is to find the base stock levels which minimize expected inventory costs per unit time for an infinite time horizon when unit manufacturing times are deterministic or exponentially distributed we derive analytical expressions that lead to the optimal base stock levels our results provide several implications about the interaction of inventories capacity utilization and variation in the production environment

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

optimal dynamic scheduling policy for a make to stock production system this paper considers the dynamic scheduling problem of a single server make to stock queue with two products for the case of poisson demands and exponential production times we show that it is optimal to produce the product with the larger b index when it is backordered if the production times are identically distributed the optimal policy can further be characterized by monotone switching curves we also prove that a base stock policy coupled with a switching curve is optimal for some initial inventory levels a simple linear switching rule for determining production priority is proposed and compared with other heuristic policies in a computational experiment

pricing and the news vendor problem a review with extensions in the newsvendor problem a decision maker facing random demand for a perishable product decides how much of it to stock for a single selling period this simple problem with its intuitively appealing solution is a crucial building block of stochastic inventory theory which comprises a vast literature focusing on operational efficiency typically in this literature market parameters such as demand and selling price are exogenous however incorporating these factors into the mode l can provide an excellent vehicle for examining how operational problems interact with marketing issues to influence decision making at the firm level in this paper we examine an extension of the newsvendor problem in which stocking quantity and selling price are set simultaneously we provide a comprehensive review that synthesizes existing results for the single period problem and develop additional results to enrich the existing knowledge base we also review and develop insight into a dynamic inventory extension of this problem and motivate the applicability of such models

risk sharing and information revelation mechanism of a one manufacturer and one retailer supply chain facing an integrated competitor this paper develops an information revelation mechanism model of a one manufacturer and one retailer supply chain facing an outside integrated competitor under demand uncertainty we investigate how the manufacturer designs a wholesale price order quantity contract to induce the retailer to report his risk sensitivity information truthfully we try to explore the effects of the outside competitor and the risk sharing rule on the optimal price service level decisions of the retailer and the optimal wholesale prices of the manufacturer we find that the strategic interaction plays an important role in the effect of risk sensitivity on the order quantity for the retailer when the fraction of the risk cost shared by the manufacturer is sufficiently large small the optimal wholesale price for the high risk averse retailer is higher lower than that for the low risk averse retailer

the competitive newsboy we consider a competitive version of the classical newsboy problem in which a firm must choose an inventory or production level for a perishable good with random demand and the optimal solution is a fractile of the demand distribution and investigate the impact of competition upon industry inventory a splitting rule specifies how initial industry demand is allocated among competing firms and how any excess demand is allocated among firms with remaining inventory we examine the relation between equilibrium inventory levels and the splitting rule and provide conditions under which there is a unique equilibrium our most general result is that if all excess demand is reallocated i e there is perfect substitutability then competition never leads to a decrease in industry inventory

a ricardian equivalence theorem on the taxation of pension funds abstract we compare the three main alternative ways of taxing pension funds of the defined contribution variety specifically the alternatives considered are equal yield taxes on contributions earnings and benefits analogous to the ricardian equivalence theorem the contributor s after tax benefit will be the same in each case

the labor illusion how operational transparency increases perceived value aubiquitous feature of even the fastest self service technology transactions is the wait conventional wisdom and operations theory suggest that the longer people wait the less satisfied they become we demonstrate that because of what we term the labor illusion when websites engage in operational transparency by signaling that they are exerting effort people can actually prefer websites with longer waits to those that return instantaneous results even when those results are identical in five experiments that simulate service experiences in the domains of online travel and online dating we demonstrate the impact of the labor illusion on service value perceptions demonstrate that perceptions of service provider effort induce feelings of reciprocity that together mediate the link between operational transparency and increased valuation and explore boundary conditions and alternative explanations 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

asymmetric cost pass through empirical evidence on the role of market power search and menu costs abstract we estimate cost pass through rates based on data for store level retail prices and wholesale costs for up to 90 different brands of milk sold in 327 retail stores across germany the abundance of the data allows us to identify heterogeneity in pass through across retailers and relate it to underlying explanatory factors such as retailer market power measures of consumer search and menu costs results from a threshold error correction process clearly provide empirical support for the rockets and feathers phenomenon prices increase more quickly than they decrease in contrast to much of the existing literature which explains the rockets and feathers phenomenon as a result of retailers exercising market power we find the opposite result the degree of asymmetry in prices is negatively related to market power decreases with the lerner index our measure of cross product search costs does not account for observable differences in asymmetric cost pass through rates between products the rockets and feathers observation is better explained by product specific differences in menu costs mistake costs and costs associated with stock outs which can lead to a loss of consumer goodwill

total factor productivity non neutral technical change and economic growth abstract the traditional approach to productivity analysis relies on the assumptions of constant return to scale neutral technical change and payments to factors according to their marginal productivity intuitively one feels that such simplifications might give biased results specifically in a planned developing economy where the last assumption is most likely violated this study develops a parametric approach to the analysis of total and specific factor productivity which does not rely on the above assumptions and applies it to the industrial sector on iraq we measure the biases in the direction of technical change and analyze their implications for employment problems in ldc s

resource allocation to defensive marketing and manufacturing strategies abstract in this paper we investigate the coordinated use of marketing and manufacturing strategies to formulate a defensive business strategy for an incumbent firm upon market entry while defensive marketing strategies have been researched extensively little has been done on defensive manufacturing strategies and even less on coordinating these two we propose a formulation for the joint formation of a defensive strategy by the marketing and production functions under budget constraint considerations the incumbent firm may allocate its resourcesto advertising and distribution expenditures as well as to manufacturing investments to reduce the unit production cost the incumbent firm has also the option of simply allocating all of its resources purely to advertising and distribution we show that while there exist cases where the optimal reaction to entry involves investments in manufacturing improvements there are also cases where defense is in marketing strategies alone we identify the market conditions that promote such reactions to entry and also provide sensitivity analysis

stock wars inventory competition in a two echelon supply chain with multiple retailers this paper studies the competitive and cooperative selection of inventory policies in a two echelon supply chain with one supplier andn retailers stochastic demand is monitored continuously retailers incur inventory holding and backorder penalty costs the supplier incurs holding costs for its inventory and backorder penalty costs for backorders at the retailers the latter cost reflects the supplier s desire to maintain adequate availability of its product to consumers previous research finds the supply chain cost minimizing reorder point policies the cooperative solution the competitive solution is a nash equilibrium a set of reorder points such that no firm can deviate from the equilibrium and lower its cost it is shown that nash equilibria exist and a method is presented to find all of them in some settings the cooperative solution is a nash equilibrium competition does not necessarily lead to supply chain inefficiency in other settings competition leads to costs that are substantially higher than optimal usually but not always the competitive supply chain carries too little inventory three cooperation strategies are discussed change incentives change equilibrium and change control a set of contracts is provided that changes the firms incentives so that the optimal policy is a nash equilibrium an equilibrium change can improve performance but does not guarantee optimal performance to change control the firms let the supplier choose all reorder points a key component in vendor managed inventory that change leads to optimal supply chain performance

note the newsvendor model with endogenous demand this paper considers a firm s price and inventory policy when it faces uncertain demand that depends on both price and inventory level the authors extend the classic newsvendor model by assuming that expected utility maximizing consumers choose between visiting the firm and consuming an exogenous outside option the outside option represents the utility the consumer forgoes when she chooses to visit the firm before knowing whether or not the product will be available the authors investigate both the case in which the firm s price is exogenous and the case in which price is chosen optimally the paper makes two contributions first the authors show that the firm holds more inventories provides a higher fill rate attracts more customers and earns higher profits when it internalizes the effect of its inventory on demand second the authors show that in the endogenous price case the firm s two dimensional decision problem can be reduced to two sequential single variable optimizations as a result the endogenous price case is as easy to solve as the exogenous price case

inventory management under market size dynamics we investigate the situation where a customer experiencing an inventory stockout at a retailer potentially leaves the firm s market in classical inventory theory a unit stockout penalty cost has been used as a surrogate to mimic the economic effect of such a departure in this study we explicitly represent this aspect of consumer behavior incorporating the diminishing effect of the consumers leaving the market upon the stochastic demand distribution in a time dynamic context the initial model considers a single firm we allow for consumer forgiveness where customers may flow back to the committed purchasing market from a nonpurchasing latent market the per period decisions include a marketing mix to attract latent and new consumers to the committed market and the setting of inventory levels we establish conditions under which the firm optimally operates a base stock inventory policy the subsequent two models consider a duopoly where the potential market for a firm is now the committed market of

modeling loss aversion and reference dependence effects on brand choice based upon a recently developed multiattribute generalization of prospect theory s value function tversky and kahneman 1991 we argue that consumer choice is influenced by the position of brands relative to multiattribute reference points and that consumers weigh losses from a reference point more than equivalent sized gains loss aversion we sketch implications of this model for understanding brand choice we develop a multinomial logit formulation of a reference dependent choice model calibrating it using scanner data in addition to providing better fit in both estimation and forecast periods than a standard multinomial logit model the model s coefficients demonstrate significant loss aversion as hypothesized we also discuss the implications of a reference dependent view of consumer choice for modeling brand choice demonstrate that loss aversion can account for asymmetric responses to changes in product characteristics and examine other implications for competitive strategy

the ricardian approach to budget deficits persistent budget deficits have increased economists interest in theories and evidence about fiscal policy this paper develops the ricardian approach and contrasts it with standard models the discussion considers from major theoretical objections to ricardian equivalence finite lifetimes imperfect capital markets uncertainty about future taxes and incomes and the distorting effects of taxation the paper then considers empirical evidence on interest rates consumption and saving and current account deficits the conclusion is that the ricardian approach is a useful first order approximation and that this approach will probably become the benchmark model for assessing fiscal policy this abstract was borrowed from another version of this item

statistical learning of service dependent demand in a multiperiod newsvendor setting we study an inventory system wherein a customer may leave the seller s market after experiencing an inventory stockout traditionally researchers and practitioners assume a single penalty cost to model this customer behavior of stockout aversion recently a stream of researchers explicitly model this customer behavior and support the traditional penalty cost approach we enrich this literature by studying the statistical learning of service dependent demand we build and solve four models a baseline model where the seller can observe the demand distribution a second model where the seller cannot observe the demand distribution but statistically learns the demand distribution a third model where the seller can learn or pay to obtain the exact information of the demand distribution and a fourth model where demand in excess of available inventory is lost and unobserved interestingly we find that all four models support the traditional penalty cost approach this result confirms the use of a state independent stockout penalty cost in the presence of demand learning more strikingly the first three models imply the same stockout penalty cost which is larger than the stockout penalty cost implied by the last model

competition and outsourcing with scale economies scale economies are commonplace in operations yet because of analytical challenges relatively little is known about how firms should compete in their presence this paper presents a model of competition between two firms that face scale economies i e each firm s cost per unit of demand is decreasing in demand a general framework is used which incorporates competition between two service providers with price and time sensitive demand a queuing game and competition between two retailers with fixed ordering costs and pricesensitive consumers an economic order quantity game reasonably general conditions are provided under which there exists at most one equilibrium with both firms participating in the market we demonstrate in the context of the queuing game that the lower cost firm in equilibrium may have a higher market share and a higher price an enviable situation we also allow each firm to outsource their production process to a supplier even if the supplier s technology is no better than the firms technology and the supplier is required to establish dedicated capacity so the supplier s scale can be no greater than either firm s scale we show that the firms strictly prefer to outsource we conclude that scale economies provide a strong motivation for outsourcing that has not previously been identified in the literature

the reference effects on a retailer s dynamic pricing and inventory strategies with strategic consumers we consider a retailer that sells the same or different versions of the product season after season at the beginning of each season stage 1 the retailer places an order and sells the product at the full price as the sales unfold the retailer has an opportunity to mark down the price stage 2 which creates an incentive for strategic consumers to delay their purchases for price discount however consumers do not know the markdown price exactly when they time their purchases instead they learn from the retailer s past prices and form their estimate of the markdown price called the reference price to decide if they purchase at the full price or wait for the markdown in the current selling season we characterize the properties of the optimal ordering and markdown decisions and show that markdowns if adopted appropriately do not necessarily destroy the stability of a business even in the presence of strategic consumers furthermore the consumers reference exhibits a mean reverting pattern under certain conditions that is the reference fluctuates around a mean value reflecting the practice of most stable businesses we conduct numerical studies to investigate the impact of consumer learning about the reference price and various system parameters on the retailer s optimal strategies and profitability in the presence of strategic consumers

spatial analysis of change trend and influencing factors of total factor productivity in china s regional construction industry total factor productivity tfp is a measure of long term economic growth and a comprehensive industry level productivity measure there are large gaps in china s regional construction industry dev

coordinating investment production and subcontracting we value the option of subcontracting to improve financial performance and system coordination by analyzing a competitive stochastic investment game with recourse the manufacturer and subcontractor decide separately on their capacity investment levels then demand uncertainty is resolved and both parties have the option to subcontract when deciding on their production and sales we analyze and present outsourcing conditions for three contract types 1 price only contracts where an ex ante transfer price is set for each unit supplied by the subcontractor 2 incomplete contracts where both parties negotiate over the subcontracting transfer and 3 state dependent price only and incomplete contracts for which we show an equivalence result while subcontracting with these three contract types can coordinate production decisions in the supply system only state dependent contracts can eliminate all decentralization costs and coordinate capacity investment decisions the minimally sufficient price only contract that coordinates our supply chain specifies transfer prices for a small number 6 in our model of contingent scenarios our game theoretic model allows the analysis of the role of transfer prices and of the bargaining power of buyer and supplier we find that sometimes firms may be better off leaving some contract parameters unspecified ex ante and agreeing to negotiate ex post also a price focused strategy for managing subcontractors can backfire because a lower transfer price may decrease the manufacturer s profit finally as with financial options the option value of subcontracting increases as markets are more volatile or more negatively correlated

incentive effects favor nonconsolidating queues in a service system the principal agent perspective in this paper we study a service network in which an agency is responsible for satisfying a constraint on the expected waiting and service time experienced by customers however the agency does not render the actual service instead it serves to coordinate independently operated facilities the coordinating agency must devise a strategy for allocating compensation and customers to the self interested operators in order to minimize its own costs for a network of two facilities we model the facilities self interested capacity decisions as the solution to a game using this analytical framework we compare two types of customer allocation one from a common queue and one from separate queues our analysis shows that it can be in the best interest of the coordinating agency to adopt a separate queue allocation scheme instead of one based on a common queue although doing so sacrifices risk pooling benefits these can be more than offset by the stronger incentives that are created for the independent facilities

competitive and cooperative inventory policies in a two stage supply chain we investigate a two stage serial supply chain with stationary stochastic demand and fixed transportation times inventory holding costs are charged at each stage and each stage may incur a consumer backorder penalty cost e g the upper stage the supplier may dislike backorders at the lower stage the retailer we consider two games in both the stages independently choose base stock policies to minimize their costs the games differ in how the firms track their inventory levels in one the firms are committed to tracking echelon inventory in the other they track local inventory we compare the policies chosen under this competitive regime to those selected to minimize total supply chain costs i e the optimal solution we show that the games nearly always have a unique nash equilibrium and it differs from the optimal solution hence competition reduces efficiency furthermore the two games equilibria are different so the tracking method influences strategic behavior we show that the system optimal solution can be achieved as a nash equilibrium using simple linear transfer payments the value of cooperation is context specific in some settings competition increases total cost by only a fraction of a percent whereas in other settings the cost increase is enormous we also discuss stackelberg equilibria

revenue management approach to stochastic capacity allocation problem abstract to formulate stochastic capacity allocation problems in a manufacturing system the concept and techniques of revenue management is applied in this research it is assumed the production capacity is stochastic and hence its exact size cannot be forecasted in advance at the time of planning there are two classes of frequent and occasional customers demanding this capacity the price rate as well as the penalty for order cancellation caused by overbooking is different for each class the model is developed mathematically and we propose an analytical solution method the properties of the optimal solution as well as the behavior of objective function are also analyzed the objective function is not concave in general however we prove it is a unimodal function and by taking advantage of this property the optimal solution is determined

dynamic capacity allocation to customers who remember past service we study the problem faced by a supplier deciding how to dynamically allocate limited capacity among a portfolio of customers who remember the fill rates provided to them in the past a customer s order quantity is positively correlated with past fill rates customers differ from one another in their contribution margins their sensitivities to the past and in their demand volatilities by analyzing and comparing policies that ignore goodwill with ones that account for it we investigate when and how customer memory effects impact supplier profits we develop an approximate dynamic programming policy that dynamically rationalizes the fill rates the firm provides to each customer this policy achieves higher rewards than margin greedy and lagrangian policies and yields insights into how a supplier can effectively manage customer memories to its advantage this paper was accepted by martin lariviere operations management

pricing and lead time decisions in decentralized supply chains this paper studies a decentralized supply chain consisting of a supplier and a retailer facing price and lead time sensitive demands a stackelberg game is constructed to analyze the price and lead time decisions by the supplier as the leader and the retailer as the follower the equilibrium strategies of the two players are obtained using the performance of the corresponding centralized system as a benchmark we show that decentralized decisions in general are inefficient and lead to inferior performance due to the double marginalization effect however further analysis shows that the decision inefficiency is strongly influenced by market and operational factors and if the operational factors are dominating it may not be significant this shows that before pursuing a coordination strategy with retailers a supplier should first improve his or her own internal operations

specification of functional form and the estimation of technical progress the use of the translog functional form to estimate technical progress may result in misleading conclusions alternative analytic functional forms in the demand system approach to measuring technical progress are compared empirically specifically translog normalized quadratic and leontief functional forms are used in combination with linear representations of the time trend variable in the respective demand systems comparisons are made with the fisher quantity index approach to measuring technical progress there is some indication that curvature violations by the translog model can lead to misleading results suggesting a preference for even the inflexible leontief model data for new zealand was used as there is much interest in the relative decline in per capita income since the 1950s and the effects on productivity of the economic reforms of the 1980s using data for the period 1960 1989 it was found that productivity growth has been low over the sample

estimating demand by using sales information inaccuracies encountered abstract demand data is integral to a company s overall information requirement this is particularly true for manufacturers and retailers with regard to capacity production and inventory planning notwithstanding the implicit inaccuracies encountered companies are predisposed to employ sales data as a primary source of information for estimating future demand in this paper by adopting a two product setting we measure inventory cost inaccuracies that arise from using sales data in estimating demand by analyzing these costs we also explore the conditions under which the resulting inaccuracies are either lessened or become acute in this context the determining rule of an induced substitution structure between the two products during stockout occasions is explicitly analyzed we use a newsboy framework in a two product environment wherein one product may be taken as a direct substitute for the other we provide necessary and sufficient optimality conditions and an extensive computational study to illustrate and support our findings and to provide additional insights on the conditions characterizing optimal stocking policies

inventory dynamics and supply chain coordination this paper extends the theory of supply chain incentive contracts from the static newsvendor framework of the existing literature to the simplest dynamic setting a manufacturer distributes a product through retailers who compete on both price and fill rates we show that inventory durability is the key factor in determining the underlying nature of incentive distortions and their contractual resolutions when the product is highly perishable retailers are biased toward excessive price competition and inadequate inventories vertical price floors or inventory buybacks subsidies for unsold inventory can coordinate incentives in both pricing and inventory decisions when the product is less perishable the distortion is reversed and vertical price ceilings or inventory penalties can coordinate incentives

innovation and total factor productivity in organic farming this article measures the contribution of innovations to total factor productivity tfp of organic olive farmers by constructing an innovation variable instead of using a time trend technical change is replaced by technical difference and tfp growth becomes tfp difference primary cross section data on organic olive enterprises from a greek region is used in the application of the stochastic frontier profit function farmers are classified into groups according to their innovative profile tfp difference among consecutive innovation groups is decomposed into technical difference and adjustment in innovativeness effects results indicate that more innovative farmers perform better than less innovative ones regarding tfp scores the rate of technical difference is always positive to the formation of tfp difference whereas the adjustment in innovativeness effects varies among the innovation groups nevertheless high tech capital is to a different extent under utilized regardless of the innovation group

competition for procurement contracts with service guarantees we consider a market with two suppliers and a set of buyers in search of procurement contracts with one of the suppliers in particular each buyer needs to process a certain volume of work and each supplier s ability to process the customers requests is constrained by a production capacity the procurement contracts include guarantees that the products will be available when needed and the buyers select a supplier based on their service delivery offers the suppliers are modeled as make to stock queues and compete for the buyers business the main objective of this paper is to determine how the procurement contracts are established between buyers and suppliers because each buyer selects a single supplier to establish the sourcing relationship the game fails to have a pure strategy nash equilibrium instead an equilibrium is defined as the limit equilibrium of some discrete action games

the role of inventory in delivery time competition the paper operationalizes the notion of shortage cost by considering the behavior of customers and competing firms and examines the role of inventory in response time competition we start with a single firm production control model in which customers are characterized by their preferences of price quality and delivery time the optimal production inventory policy and the optimal choice between make to order and make to stock operations are determined in simple newsboy like formulas the basic model is then extended to an n firm market game in which firms compete for orders from the aspect of early delivery one could think of this setting as an oligopoly racing market the analysis shows that competition can breed a demand for produce to stock just as other economic phenomena such as economies of scale uncertainty or seasonality can induce make to stock and that delivery time competition increases the buyer s welfare while decreasing the producer s welfare

modeling the role of retail price formats and retailer competition types on production schedule strategy abstract to study the determinants of choice between make to order mto and make to stock mts production scientists have traditionally focused on production specific factors however the choice can be also influenced by marketing specific factors such as the pricing strategy of retailers this paper therefore develops a modeling framework to link the determination of the optimal production strategy of mts mto to the retailing strategy of edlp hilo we characterize an optimal production strategy as one that maximizes total system wide profits in a centralized system we show that the optimum production strategy would depend on whether the manufacturer is delivering to an every day low pricing edlp store or to a high low pricing store hi lo additionally the production plan is demonstrated to be a function of the nature and type of competition in the market in particular we study the duopoly model of competition under both bertrand and stackelberg conjectures

pricing production scheduling and delivery time competition this paper studies competition between firms that produce goods or services for customers sensitive to delay time firms compete by setting prices and production rates for each type of customer and by choosing scheduling policies the existence of a competitive equilibrium is proved the competitive equilibrium is well defined whether or not a firm can differentiate between customers based upon physical characteristics because each customer has incentive to truthfully reveal its delay cost further insights are derived in two special cases a unique equilibrium exists for each of the cases in the first case firms are differentiated by cost mean processing time and processing time variability but customers are homogeneous the conclusions include that a faster lower variability and lower cost firm always has a larger market share higher capacity utilization and higher profits however this firm may have higher prices and faster delivery time or lower prices and longer delivery time in the second

asymmetric consumer learning and inventory competition we develop a model of consumer learning and choice behavior in response to uncertain service in the marketplace learning could be asymmetric that is consumers may associate different weights with positive and negative experiences under this consumer model we characterize the steady state distribution of demand for retailers given that each retailer holds a constant in stock service level we then consider a noncooperative game in steady state between two retailers competing on the basis of their service levels the demand distributions of retailers in this game are modeled using a multiplicative aggregate market share model in which the mean demands are obtained from the steady state results for individual purchases but the model is simplified in other respects for tractability our model yields a unique pure strategy nash equilibrium we show that asymmetry in consumer learning has a significant impact on the optimal service levels market shares and profits of the retailers when retailers have different costs it also determines the extent of competitive advantage enjoyed by the lower cost retailer

combined pricing and inventory control under uncertainty this paper addresses the simultaneous determination of pricing and inventory replenishment strategies in the face of demand uncertainty more specifically we analyze the following single item periodic review model demands in consecutive periods are independent but their distributions depend on the item s price in accordance with general stochastic demand functions the price charged in any given period can be specified dynamically as a function of the state of the system a replenishment order may be placed at the beginning of some or all of the periods stockouts are fully backlogged we address both finite and infinite horizon models with the objective of maximizing total expected discounted profit or its time average value assuming that prices can either be adjusted arbitrarily upward or downward or that they can only be decreased we characterize the structure of an optimal combined pricing and inventory strategy for all of the above types of models we also develop an efficient value iteration method to compute these optimal strategies finally we report on an extensive numerical study that characterizes various qualitative properties of the optimal strategies and corresponding optimal profit values

a general equilibrium model for industries with price and service competition this paper develops a stochastic general equilibrium inventory model for an oligopoly in which all inventory constraint parameters are endogenously determined we propose several systems of demand processes whose distributions are functions of all retailers prices and all retailers service levels we proceed with the investigation of the equilibrium behavior of infinite horizon models for industries facing this type of generalized competition under demand uncertainty we systematically consider the following three competition scenarios 1 price competition only here we assume that the firms service levels are exogenously chosen but characterize how the price and inventory strategy equilibrium vary with the chosen service levels 2 simultaneous price and service level competition here each of the firms simultaneously chooses a service level and a combined price and inventory strategy 3 two stage competition the firms make their competitive choices sequentially in a first stage all firms simultaneously choose a service level in a second stage the firms simultaneously choose a combined pricing and inventory strategy with full knowledge of the service levels selected by all competitors we show that in all of the above settings a nash equilibrium of infinite horizon stationary strategies exists and that it is of a simple structure provided a nash equilibrium exists in a so called reduced game we pay particular attention to the question of whether a firm can choose its service level on the basis of its own input characteristics i e its cost parameters and demand function only we also investigate under which of the demand models a firm under simultaneous competition responds to a change in the exogenously specified characteristics of the various competitors by either i adjusting its service level and price in the same direction thereby compensating for price increases decreases by offering improved inferior service or ii adjusting them in opposite directions thereby simultaneously offering better or worse prices and service

inventory rationing in a make to stock production system with several demand classes and lost sales this paper considers the stock rationing problem of a single item make to stock production system with several demand classes and lost sales for the case of poisson demands and exponential production times we show that the optimal policy can be characterized by a sequence of monotone stock rationing levels for each demand class there exists a stock rationing level at or below which it is optimal to start rejecting the demand of this class in anticipation of future arrival of higher priority demands a simple queueing model is analyzed to compute the operating cost of a rationing policy in a numerical study we compare the optimal rationing policy with a first come first served policy to investigate the benefit of stock rationing under different operating conditions of the system

a supply chain network economic model with time based competition abstract this paper presents an integrated model for time cost competition between supply chains with heterogeneous customers the firms in our model can offer various time options for their production service to time sensitive customers this gives rise of a new concept of time based supply chain which we call t chain to be the basic element in the competition and extends the inter supply chain competition to a new dimension of time assuming the customers are heterogeneous in time cost bi criteria decision making we integrate the discrete choice theory into supply chain network competition and formulate the equilibrium conditions as a multinomial logit based variational inequality problem numerical examples are presented for model illustration and managerial insights such as profit maximization for a firm who participates in this supply chain network

logit demand estimation under competitive pricing behavior an equilibrium framework discrete choice models of demand have typically been estimated assuming that prices are exogenous since unobservable to the researcher product attributes such as coupon availability may impact consumer utility as well as price setting by firms we treat prices as endogenous specifically prices are assumed to be the equilibrium outcomes of nash competition among manufacturers and retailers to empirically validate the assumptions we estimate logit demand systems jointly with equilibrium pricing equations for two product categories using retail scanner data and cost data on factor prices in each category we find statistical evidence of price endogeneity we also find that the estimates of the price response parameter and the brand specific constants are generally biased downward when the endogeneity of prices is ignored our framework provides explicit estimates of the value created by a brand i e the difference between consumers willingness to pay for a brand and its cost of production we develop theoretical propositions about the relationship between value creation and competitive advantage for logit demand systems and use our empirical results to illustrate how firms use alternative value creation strategies to accomplish competitive advantage

optimal service speeds in a competitive environment this is a study of the economic behavior of vendors of service in competition a simple model with two competing exponential servers and poisson arrivals is considered each server is free to choose his own service rate at a cost per time unit that is strictly convex and increasing there is a fixed reward to a server for each customer that he serves the model is designed to study one specific aspect of competition namely competition in speed of service as a means for capturing a larger market share in order to maximize long run expected profit per time unit a two person strategic game is formulated and its solutions are characterized depending on the revenue per customer served and on the cost of maintaining service rates the following three situations may arise i a unique symmetric strategic nash equilibrium in which expected waiting time is infinite ii a unique symmetric strategic equilibrium in which expected waiting time is finite and iii several nonsymmetric strategic equilibria with infinite expected waiting time an explicit expression for the market share of each server as a function of the service rates of the two servers is also given

optimal inventory policies under service sensitive demand the service level provided by a retailer influences demand and sales in several ways in the short run sales can fall short of demand when customers experience stockouts and choose not to backorder in the long run demand itself may decline as customers who experience excessive stockouts shift permanently to more reliable sources the traditional approach to determining inventory policies assumes a fixed stockout cost attributable to each stockout occasion in practice stockout costs are difficult to determine at least in part because they reflect the long term loss of demand due to inadequate service in this paper we model the response of long run demand to the service level of the retailer and determine optimal order up to inventory policies in the presence of service sensitive demand we show under what conditions inventory policy is sensitive to both the mean and the variance of long run demand

procuring fast delivery sole sourcing with information asymmetry this paper studies a queuing model in which a buyer sources a good or service from a single supplier chosen from a pool of suppliers the buyer seeks to minimize the sum of her procurement and operating costs the latter of which depends on the suppliers lead time the selected supplier can regulate his lead time but faster lead times are costly although the buyer selects the supplier to source from possibly via an auction and dictates the contractual terms the buyers bargaining power is limited by asymmetric information the buyer only has an estimate of the suppliers costs while the suppliers know their costs precisely we identify a procurement mechanism that minimizes the buyers total cost procurement plus operating this mechanism is not simple it is a numerically derived nonlinear menu of contracts therefore we study several simpler mechanisms e g one that charges a late fee and one that specifies a fixed lead time requirement no menus no nonlinear functions we find that simple mechanisms are nearly optimal generally within 1 of optimal because asymmetric information conveys significant protection to the supplier i e the supplier is able to retain most of the benefit of having a lower cost renegotiation is another concern with the optimal mechanism because it does not minimize the supply chains cost the firms can be both better off if they throw away the contract and start over interestingly we find that the potential gain from renegotiation is relatively small with either the optimal or our simple mechanisms we conclude that our simple mechanisms are quite attractive along all relevant dimensions buyers performance supply chain performance simplicity and robustness to renegotiation

optimal operating policies for multiplant stochastic manufacturing systems in a changing environment this paper addresses the horizontal coordination between production units located in different countries within a supply chain in a changing environment the model incorporates 1 congestion and delay through uncertainties in demand and processing times 2 a changing production cost environment through uncertainty in an environmental state such as the exchange rate and 3 allowing production to stock the main contribution of the paper is to characterize the optimal production policy assuming no switchover cost as a barrier type control policy for a series of models for each plant there is a barrier function defined on the environmental state that gives the total worldwide stock level barrier this plant should be operated if and only if the stock level is below this barrier the authors also show that in a simple setting of two plants in different countries the barrier functions are not always monotone in the exchange rate even when the production costs are the authors present a condition under which the control barriers are shown to be monotone under this condition and with only two plants it is optimal to follow a primary secondary plant policy in which given a fixed environmental state it is optimal to operate both plants when stock is low only the primary plant when stock is moderate and neither when stock is high furthermore the roles of the plants switch as the environmental state passes through the equal production cost state in addition the firm seeks to carry the most stock as a hedge against future environmental state moves when one plant is significantly cheaper than the other the firm seeks to carry the least stock when both plants are equally costly to operate

side payment contracts in two person nonzero sum supply chain games review discussion and applications this paper investigates supply chain coordination with side payment contracts we first summarize specific side payment contracts and present our review on the literature that developed general side payment schemes to coordinate supply chains following our review we discuss two criteria that a proper side payment contract must satisfy and accordingly introduce a decision dependent transfer payment function and a constant transfer term we present the condition that the transfer function must satisfy and use nash arbitration scheme and shapley value to compute the constant transfer term and derive its closed form solution next we provide a five step procedure for the development of side payment contract and apply it to four supply chain games cournot and bertrand games a two retailer supply chain game with substitutable products and a one supplier one retailer supply chain more specifically for the cournot game we construct a linear transfer function and a constant side payment to coordinate two producers for the bertrand game we build a nonlinear transfer function which is equivalent to a revenue sharing contract and show that the constant term is zero and two firms in the game equally share the system wide profit for a supply chain with substitutable products we present a side payment contract to coordinate two retailers for a two echelon supply chain we develop a proper side payment scheme that can coordinate the supply chain and also help reduce the impact of forward buying on supply chain performance

profit efficiency among bangladeshi rice farmers abstract production inefficiency is usually analyzed by its three components technical allocative and scale efficiency in this study we provide a direct measure of production efficiency of the bangladeshi rice farmers using a stochastic profit frontier and inefficiency effects model the data which are for 1996 include seven conventional inputs and several other background factors affecting production of modern or high yielding varieties hyvs of rice spread across 21 villages in three agro ecological regions of bangladesh the results show that there are high levels of inefficiency in modern rice cultivation the mean level of profit efficiency is 77 suggesting that an estimated 23 of the profit is lost due to a combination of technical allocative and scale inefficiency in modern rice production the efficiency differences are explained largely by infrastructure soil fertility experience extension services tenancy and share of non agricultural income

inventory competition under dynamic consumer choice we analyze a model of inventory competition among n firms that provide competing substitutable goods each firm chooses initial inventory levels for their good in a single period newsboy like inventory model customers choose dynamically based on current availability so the inventory levels at one firm affect the demand of all competingfirms this creates a strategic interaction amongthe firms inventory decisions our work extends earlier work on variations of this problem by karjalainen 1992 lippman and mccardle 1997 and parlar 1988 specifically we model demand in a more realistic way as a stochastic sequence of heterogeneous consumers who choose dynamically from amongthe available goods or choose not to purchase based on a utility maximization criterion we also use a sample path analysis so minimal assumptions are imposed on this demand process we characterize the nash equilibrium of the resulting stocking game and prove it is unique in the symmetric case we show there is a bias toward overstocking caused by competition specifically reducing the quantity stocked at any equilibrium of the game increases total system profits and at any joint optimal set of stocking levels each firm has an individual incentive to increase its own stock for the symmetric case we show that as the number of competing firms increases the overstockingbecomes so severe that total system and individual firm profits approach zero finally we propose a stochastic gradient algorithm for computing equilibria and provide several numerical examples

promised delivery time and capacity games in time based competition we investigate firms competitive behaviors in industries where customers are sensitive to both promised delivery time pdt and quality of service qos measured by the on time delivery rate to study the competition in pdt at the marketing level we construct an oligopoly game with an external qos requirement we show that there exists a unique nash equilibrium and the equilibrium qos exhibits a switching surface structure with respect to capacities to study the competition in capacity at the strategic level we construct a two stage game in which the firms compete in terms of their capacities in stage 1 and in terms of pdt in stage 2 we show the existence of two different types of pure strategy equilibria and characterize them this study provides the following insights an index of time based competitive advantage itca and the first mover advantage determine the positions of the firms in time based competition either the well known prisoner s dilemma or off equilibrium behaviors due to different preferences for equilibria when multiple equilibria exist may lead the firms to overinvest in capacity but no one may gain a competitive advantage a uniform improvement in internal efficiency i e a uniform capacity cost reduction may harm everyone quality differentiation i e going beyond the qos benchmark plays a dual role in time based competition either helping a firm with a larger itca to compete more effectively or helping a firm possibly with a smaller itca to preempt competitors and protect its market advantage this paper was accepted by paul h zipkin operations and supply chain management

analysis of an inventory system under backorder correlated deterministic demand and geometric supply process abstract in this article we propose a single item periodic review model that investigates the effects of changes in the demand process that occur after stockout realizations we investigate a system where the demands in successive periods are deterministic but affected by the backorder realizations in order to capture the effects of changes in the demand process we use a geometric type supply availability we analytically derive the necessary components for obtaining profit related performance measures and provide computational analysis

technical note an optimal policy for joint dynamic price and lead time quotation for a dynamic joint price and lead time quotation problem with a fairly general demand function we show that the policy consisting of a threshold and a reward maximizing lead time is optimal this policy offers some interesting managerial insights under this policy finding the exact optimal quotation can be accomplished by single variable policy iterations of unimodal value functions

on the relationship between inventory costs and variety benefits in retailassortments consider a category of product variants distinguished by some attribute such as color or flavor a retailer must construct an assortment for the category i e select a subset variants to stock and determine purchase quantities for each offered variant we analyze this problem using a multinomial logit model to describe the consumer choice process and a newsboy model to represent the retailer s inventory cost we show that the optimal assortment has a simple structure and provide insights on how various factors affect the optimal level of assortment variety we also develop a formal definition of the level of fashion in a category using the theory of majorization and examine its implications for category profits

competition and product quality in the supermarket industry this article analyzes the effect of competition on a supermarket firm s incentive to provide product quality in the supermarket industry product availability is an important measure of quality using u s consumer price index microdata to track inventory shortfalls i find that stores facing more intense competition have fewer shortfalls competition from walmart the most significant shock to industry market structure in half a century decreased shortfalls among large chains by about a third the risk that customers will switch stores appears to provide competitors with a strong incentive to invest in product quality

inventory control with information about supply conditions this paper presents an inventory control model which includes a markovian model of the supply system as that system evolves over time so do the replenishment leadtimes the optimal policy has the same structure as in standard models but its parameters change dynamically to reflect current supply conditions in this setting contrary to conventional wisdom a longer leadtime does not necessarily imply more inventory the leadtime is important but so is a concept we call order coverage

a general index of technical change this paper outlines a procedure for estimating a general index of technical change within the context of a quite general production technology specifically when panel data are available for firms in an industry time specific dummies can be combined in a nonlinear estimation procedure to yield a general index of technical change that may be both nonneutral and scale augmenting this approach offers numerous advantages over the traditional time trend representation of technical change for example the general index can serve as the basis for analysis of the determinants of technical change results for a sample of 30 electric utilities over the period 1951 78 show that the productivity decline of the 1970s can be attributed primarily to sulphur oxide restrictions and secularly declining capacity utilization due to rapidly increasing peak load demands

revenue management of a make to stock queue motivated by recent electronic marketplaces we consider a single product make to stock manufacturing system that uses two alternative selling channels long term contracts and a spot market of electronic orders at time 0 the risk averse manufacturer selects the long term contract price at which point buyers choose one of the two channels the resulting long term contract demand is a deterministic fluid while the spot market demand is modeled as a stochastic renewal process an exponential reflected random walk model is used to model the spot market price which is correlated with the spot market demand process the manufacturer accepts or rejects each electronic order and long term contracts and accepted electronic orders are backordered if necessary the manufacturer s control problem is to select the optimal long term contract price as well as the optimal production i e busy idle and electronic order admission policies to maximize revenue minus inventory holding and backorder costs under heavy traffic conditions the problem is approximated by a diffusion control problem and analytical approximations are used to derive a policy that is simple and reasonably accurate and robust

backorder penalty cost coefficient b what could it be abstract the classical economic order quantity eoq model with planned penalized backorders pb relies on postulating a value for the backorder penalty cost coefficient b which is supposed to reflect the intangible adverse effect of the future loss of customer goodwill following a stockout recognizing that the effect of the future loss of customer goodwill should be not a direct penalty cost but a change in future demand schwartz 1966 a new approach to stockout penalties management science 12 12 b538 b544 modified the classical eoq pb model by eliminating the backorder penalty cost term from the objective function and assuming that the long run demand rate is a decreasing strictly convex function of the customer s disappointment factor defined as the complement of the demand fill rate following a stockout which in turn is an increasing strictly convex function of the demand fill rate he called the new model a perturbed demand pd model schwartz provided convincing justification for his pd model and presented several variations of it in a follow up paper but he did not solve any of these models in this paper we solve schwartz s original pd model and its variations and we discuss the implications of their solutions thus filling a gap in the literature left by schwartz moreover having been convinced that schwartz s approach is more valid than the classical approach for representing the effect of the loss of customer goodwill following a stockout but also recognizing that the classical approach is far more popular than the pd approach because of its simplicity and because of tradition we use the solution of the pd model to infer the value of b in the classical model thus providing one possible answer to the question what could b be a noteworthy implication of the solution of schwartz s original pd model is that the optimal fill rate is always 0 or 1 rendering the inferred value of b in the classical model 0 or respectively suspecting that the property of the pd function which is most likely responsible for producing this bang bang type of result is strict convexity we show that for the case where the pd function is proportional to an integer power say n of the fill rate the optimal fill rate is always 0 or 1 if and only if n 1 in which case the pd function is strictly convex in the fill rate

optimal operating policies in the presence of exchange rate variability we study the structure of the optimal policies for a firm operating plants in different countries the relative costs of production between the plants are assumed to vary over time due to economic and political factors such as exchange rates inflation taxes and tariffs based on the costs the firm can alter the quantity produced in each plant we determine the structure of the optimal policies for deciding when and by how much to alter the production quantities when the switch over costs are linear or step functions regardless of whether the variable production costs are concave or piece wise linear convex and regardless of whether the firm is supplying one or more markets the optimal policy is always a barrier policy the optimal barriers can be determined by using linear programming techniques and the optimal costs can be computed by solving a system of linear equations when the number of optimal barriers is two the optimal expected costs and the condition that determines the optimal barriers are explicitly derived

price versus production postponement capacity and competition this article presents a comparative analysis of possible postponement strategies in a two stage decision model where firms make three decisions capacity investment production inventory quantity and price typically investments are made while the demand curve is uncertain the strategies differ in the timing of the operational decisions relative to the realization of uncertainty we show how competition uncertainty and the timing of operational decisions influence the strategic investment decision of the firm and its value in contrast to production postponement price postponement makes the investment and production inventory decisions relatively insensitive to uncertainty this suggests that managers can make optimal capacity decisions by deterministic reasoning if they have some price flexibility under price postponement additional postponement of production has relatively small incremental value therefore it may be worthwhile to consider flexible ex post pricing before production postponement reengineering while more postponement increases firm value it is counterintuitive that this also makes the optimal capacity decision more sensitive to uncertainty we highlight the different impact of more timely information which leads to higher investment and inventories and of reduced demand uncertainty which decreases investment and inventories our analysis suggests appropriateness conditions for simple make to stock and make to order strategies we also present technical sufficiency and uniqueness conditions under price postponement these results extend to oligopolistic and perfect competition for which pure equilibria are derived interestingly the relative value of operational postponement techniques seems to increase as the industry becomes more competitive

price delivery time guarantees and capacity selection this paper studies the impact of using delivery time guarantees as a competitive strategy in service industries where demands are sensitive to both price and delivery time we assume that delivery reliability is crucial and investment in capacity expansion is plausible in order to maintain a high probability of delivering the time guarantee a mathematical framework is proposed to understand the interrelations among pricing delivery time guarantee and capacity expansion decisions specifically an optimization model is developed to determine the joint optimal selection of these three important decision variables with an objective of maximizing the average net profit we characterize the optimal decisions and study their qualitative behaviors as various parameters change we further present a numerical example to illustrate how the results of our model can be used to provide useful managerial insights for selecting the best competing strategies for firms with different operating characteristics our model and results are also applicable to a make to order manufacturing environment

dynamic pricing with loss averse consumers and peak end anchoring we study the dynamic pricing implications of a new behaviorally motivated reference price mechanism based on the peak end memory mode this model suggests that consumers anchor on a reference price that is a weighted average of the lowest and most recent prices loss averse consumers are more sensitive to perceived losses than gains relative to this reference price we find that a range of constant pricing policies is optimal for the corresponding dynamic pricing problem this range is wider the more consumers anchor on lowest prices and it persists when buyers are loss neutral in contrast with previous literature in a transient regime the optimal pricing policy is monotone and converges to a steady state price which is lower the more extreme and salient the low price anchor is our results suggest that behavioral regularities such as peak end anchoring and loss aversion limit the benefits of varying prices and caution that the adverse effects of deep discounts on the firm s optimal prices and profits might be more enduring than previous models predict

manufacturer incentives to improve retail service levels in this paper we provide a solution to the problem of how a manufacturer can provide an incentive to a separately owned retailer to raise its service level above the level it would choose on its own we analyze the effects the manufacturer s incentive has on the individual profits of the retailer and manufacturer as well as their joint profits our work is an application of game theory in which we tackle the problem posed by separate ownership of the two firms and the resulting conflict over the gains from cooperation we utilize a plausible model of service sensitive demand one which is relatively free of ad hoc assumptions our approach has the strength that it proposes a credible solution to the problem of manufacturer retailer cooperation when profits are sensitive to retail service levels our results indicate that the optimal level of incentive for the manufacturer and the resulting shares of the manufacturer and retailer in increased profits are particularly sensitive to the underlying variability of demand and to the relative variability of additional demand induced by higher service levels