perishable inventory theory a review this paper reviews the relevant literature on the problem of determining suitable ordering policies for both fixed life perishable inventory and inventory subject to continuous exponential decay we consider both deterministic and stochastic demand for single and multiple products both optimal and sub optimal order policies are discussed in addition a brief review of the application of these models to blood bank management is included the review concludes with a discussion of some of the interesting open research questions in the area

vertical control of price and inventory this paper offers a simple approach to the theory of decentralizing inventory and pricing decisions along a supply chain we consider an upstream manufacturer selling to two outlets which compete as differentiated duopolists and face uncertain demand demand spillovers between the outlets arise in the event of stockouts the price mechanism in which each outlet pays a two part price and chooses price and inventory virtually never coordinates incentives efficiently contracts that can elicit first best decisions include resale price floors or buy back policies retailer held options to sell inventory back to the manufacturers

the role of market forces in assuring contractual performance the conditions under which transactors can use the market repeat purchase mechanism of contract enforcement are examined increased price is shown to be a means of assuring contractual performance a necessary and sufficient condition for performance is the existence of price sufficiently above salvageable production costs so that the nonperforming firm loses a discounted steam of rents on future sales which is greater than the wealth increase from nonperformance this will generally imply a market price greater than the perfectly competitive price and rationalize investments in firm specific assets advertising investments thereby become a positive indicator of likely performance

vertical contracts in the video rental industry a large body of theoretical work has explored the channels through which vertical contracts can induce efficiency improvements however it is also important to study vertical contracts empirically in order to gain insight into the relative size of different types of efficiency gains in this paper i empirically analyse a contractual innovation in the vertically separated video rental industry prior to 1998 video stores obtained inventory from movie distributors using simple linear pricing contracts in 1998 revenuesharing contracts were widely adopted i investigate the effect of the introduction of revenue sharing contracts on firms profits and consumer welfare i analyse a new panel data set of home video retailers that includes information on individual retailers contract and inventory choices as well as rentals and contract terms for 246 movie titles and 6137 retailers in the u s during each week of 1998 and 1999 and the first half of 2000 a structural econometric model of firms behaviour is developed that describes the nature of firms contract choices estimates from this model indicate that both upstream and downstream profits increase by 10 under the revenue sharing contract for popular titles for less popular titles the effects can be even larger i also estimate that consumers benefit when revenue sharing contracts are adopted

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

revenue sharing and vertical control in the video rental industry revenue sharing contracts in which retailers pay a royalty on sales to their suppliers are now widely used in the video rental industry we show that revenue sharing is valuable in vertically separated industries in which demand is either stochastic unpredictable or variable e g systematically declining downstream inventory is chosen before demand is realized and downstream firms engage in intrabrand competition unlike two part tariffs revenue sharing achieves the first best outcome by softening retail price competition without distorting retailers inventory decisions our theories are also consistent with trends in prices and availability following retailers adoption of revenue sharing contracts

managerial incentive problems a dynamic perspective the paper studies how a person s concern for a future career may influence his or her incentives to put in effort or make decisions on the job in the model the person s productive abilities are revealed over time through observations of performance there are no explicit output contingent contracts but since the wage in each period is based on expected output and expected output depends on assessed ability an implicit contract links today s performance to future wages an incentive problem arises from the person s ability and desire to influence the learning process and therefore the wage process by taking unobserved actions that affect today s performance the fundamental incongruity in preferences is between the individual s concern for human capital returns and the firm s concern for financial returns the two need be only weakly related it is shown that career motives can be beneficial as well as detrimental depending on how well the two kinds of capital returns are aligned it is well understood by now that informational externalities may place special demands on the organization of economic exchange simple price mediated markets will frequently fail in the presence of asymmetric information in that case more elaborate contractual arrangements have to be used as substitutes for the price system lately considerable effort has been devoted to the analysis of contracting under incomplete information with the objective to understand the range of economic institutions that emerge in response to the failure of the price system the analysis of moral hazard has played a prominent role in this development moral hazard problems arise when for some reason or another transacting parties cannot contract contingent on the delivery of the good for instance in buying labour services it may be that the amount of labour supplied is not directly observable precluding a simple exchange of wage for labour as a partial remedy to this problem an imperfect mutually observed signal about the supply of labour can be used as a proxy in the contract frequently output is taken as such a proxy the drawback is that output is often influenced by other factors than labour input which induce undesirable risk into the contract one is therefore faced with a tradeoff between allocating risk associated with incomplete observability and providing incentives for a proper supply of labour gaining insight into this tradeoff is important not only for understanding contracting in the small e g managerial incentive schemes but also because it is closely related to the fundamental tension between equity and efficiency in the society as a whole while our understanding of moral hazard has advanced a lot in past years it is clear that much work remains an important question that has received little attention until

review of inventory systems with deterioration since 2001 abstract this paper presents an up to date review of the advances made in the field of inventory control of perishable items deteriorating inventory the last extensive review on this topic dates back to 2001 goyal s k and giri b c recent trends in modeling of deteriorating inventory european journal of operational research 134 1 16 since then over two hundred articles on this subject have been published in the major journals on inventory control indicating the need for a new review we use the classification of goyal and giri based on shelf life characteristics and demand characteristics contributions are highlighted by discussing main system characteristics including price discounts backordering or lost sales single or multiple items one or two warehouses single or multi echelon average cost or discounted cash flow and payment delay

demand uncertainty inventories and resale price maintenance we show that a manufacturer facing uncertain demand and selling through a competitive retail market may wish to support adequate retail inventories by preventing the emergence of discount retailers in our model discounters offer low prices made possible by low probability of being saddled with unsold inventories in the event of slack demand full price retailers are compensated for a higher probability of unsold inventories by a higher retail price when they sell we show that preventing discounting increases the manufacturer s wholesale demand and profits and we delineate demand conditions under which equilibrium inventory holding and consumer welfare increase

a quantized approach to rational inattention abstract in this paper i propose a model of rational inattention where the choice variable is a deterministic function of the exogenous variables and still only a finite amount of information is being used this holds provided the choice variable is discrete rather than continuous that is the mapping from the realization of the exogenous variables to the endogenous ones is piece wise constant thus limited information is now a source of lumpiness in behavior rather than a source of noise the approach is applied to a simple static model of price setting where individual price setters face aggregate monetary shocks and idiosyncratic productivity shocks the effect of aggregate money shocks on output and prices is studied it is shown that as the variance of idiosyncratic shocks become large the aggregate log price level converges to a linear function of the aggregate money shock with a coefficient which is strictly between 0 and 1 consequently unanticipated aggregate money shocks have real effects on output in contrast to the sticky price model of caplin and spulber 1987 but these effects are smaller than in standard rational inattention models or in the lucas 1972 misperception model

competitive price matching guarantees equilibrium analysis of the availability verification clause under demand uncertainty price matching guarantees involve a retailer matching the lower price of a competitor for an identical product in reality retailers often make such guarantees contingent on the verification of product availability at the competitor s location and decline a price match request if the product is not available there this creates certain consternation on the part of customers in this paper we investigate the availability contingency strategy from the perspectives of both the retailers and the customers our analysis shows that availability contingency clauses intensify inventory competition between retailers and reinstitutes price competition which is otherwise eliminated by unconditional price matching guarantees consequently despite what customers may think about the availability verification it actually increases their surplus on the other hand such a clause reduces profits and hence is not the equilibrium strategy for retailers subsequently we discuss how a likely customer behaviour pattern may be a plausible explanation regarding the use of the clause by the retailers in practice this paper was accepted by yossi aviv operations management

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

demand uncertainty and price maintenance markdowns as destructive competition this paper offers a new theory of destructive competition the authors compare minimum resale price maintenance to retail market clearing in a model with a monopolistic manufacturer selling to competitive retailers in both the resale price maintenance and flexible price games retailers must order inventories before the realization of demand uncertainty the authors find that manufacturer profits and equilibrium inventories are higher under resale price maintenance than under market clearing surprisingly consumer surplus can also be higher in which case unfettered retail competition can legitimately be called destructive copyright 1997 by american economic association

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

vertical price controls with uncertain demand a manufacturer distributes output before knowing demand and thus risks making more than its rivalrous independent retailers can sell at the monopoly price if demand is low retailers may therefore resell more than the joint profit maximizing output anticipating this they will not pay as much for the merchandise ex ante as they would if the manufacturer could commit to preventing rivalry the manufacturer has many options including vertical integration chain outlets restricted output buy backs just in time deliveries and minimum resale prices the article discusses each option s advantages and disadvantages and concludes that all roads lead to resale price maintenance the article closes with an alternative to the dealercartel hypothesis for minimum resale prices

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

agency costs in a supply chain with demand uncertainty and price competition in this paper we model a manufacturer that contracts with two retailers who then choose retail prices and stocking quantities endogenously in a bayesian nash equilibrium if the manufacturer designs a contract that is accepted by both retailers it sets the wholesale price as a compromise between two conflicting roles reducing intrabrand retail price competition and inducing retailers to stock closer to first best levels that is optimum for the supply chain as a whole in equilibrium fill rates are less than first best if on the other hand the manufacturer eliminates retail competition by designing a contract accepted by only one retailer the assignment of consumers to retailers is inefficient in either equilibrium the performance of the supply chain is strictly less than first best however the manufacturer achieves first best retail prices and fill rates if it can subsidize the retailers leftover inventory absent such subsidies the two retailer equilibrium arises when the two retailers compete less intensively in that equilibrium numerical results indicate that the value of subsidizing unsold inventory is increasing in demand uncertainty intensity of retail competition and salvage value of inventory and is decreasing in manufacturing cost and opportunity cost of shelf space

on the strategic importance of prices versus quantities in this article i investigate three single shot models of differentiated products oligopoly in each model firms choose both output and price the demand cost and spillover demand specifications are quite general and there are three main results first with simultaneous choice there is no pure strategy noncooperative equilibrium second with output chosen first and announced to all firms before the choice of price equilibrium sometimes exists and when it does it is the same as in a quantity only model third with price chosen and announced first equilibrium always exists and is the same as in a price only model

vertical contracts in a supply chain and the bullwhip effect this paper shows that decentralized supply chains in which upstream firms use linear wholesale prices may experience lower upstream production and downstream sales volatility than vertically inte

regime types markets and war the importance of pervasive rents in foreign policy several possible explanations have been given for why democracies maintain peaceful relations among themselves this article examines the role of domestic political institutions in establishing market relations and the degree of interference in domestic economic relations it is argued that less representative regimes are more likely to establish pervasive policies delivering rents than more representative regimes pervasive rents in turn alter the relationship of domestic and international prices which affects how countries choose to participate in the international economy republics where rent seeking may be pervasive but rents tend not to be distorting fit into liberal international systems with greater ease than other types of regimes republics therefore find it more attractive to meet their international needs through trade than do nonrepublican regimes by exploring the importance of regime type for the formation of international preferences questions about relations between democratic st

stack them high let em fly lot sizing policies when inventories stimulate demand in some retail contexts stocking large quantities of inventory may not only improve service levels but can also stimulate demand for products having demand rates that increase with inventory levels we analyze the effect of stocking decisions on firm profitability to develop managerial insights regarding the structure of the optimal inventory policy and to understand how this policy differs from traditional approaches when inventories stimulate demand iteratively applying the standard economic order quantity eoq model by setting the demand rate parameter equal to the observed average demand rate in prior cycles yields an equilibrium order quantity that is robust to demand parameter misestimation but is suboptimal the profit maximizing policy orders larger quantities and can replenish inventory even before on hand stock fully depletes using an extension of a standard inventory dependent demand model from the literature we first provide a convenient characterization of products that require early replenishment we demonstrate that the optimal cycle time is largely governed by the conventional trade off between ordering and holding costs whereas the reorder point relates to a promotions oriented cost benefit perspective we show that the optimal policy yields significantly higher profits than cost based inventory policies underscoring the importance of profit driven inventory management