joint pricing and ordering policy for two echelon imperfect production inventory model with two cycles abstract this study deals with an imperfect epq economic production quantity price dependent inventory model over two types of cycles in the first cycle the retailer sells only good product with actual price and in the second he sells the products with a discount price in the production run time the non conforming items are produced at a random rate and they are reworked after the regular production run time and the reworked items are almost perfect as good as original quality items the retailer starts the second cycle when a certain percent of good items are left to him after the completion of regular production the retailer continues simultaneously two cycles up to which both types of the products are available to him now our objective is to find out optimal ordering lot size and optimal price for which the profit of the integrated model is maximum also we check the best strategy of retailer for the time of starting second cycle a numerical example is provided to illustrate the behavior and application of the model

optimal production lot with imperfect production process under permissible delay in payments and complete backlogging abstract the traditional economic production quantity epq model assumes that the production products are all perfect it is not always true in the real production system due to imperfect production process or other factors imperfect quality items may be produced furthermore it is well known that the total production inventory costs can be reduced by reworking the imperfect quality items produced with a relatively smaller additional reworking and holding costs in addition the permissible delay in payments offered by the supplier is widely adopted in the practical business market in this study we explore the effects of the reworking imperfect quality items and trade credit on the epq model with imperfect production processes and complete backlogging a mathematical model which includes the reworking and shortage costs interest earned and interest charged is presented besides an arithmetic geometric mean inequality approach is employed and an algorithm is developed to find the optimal production policy furthermore some numerical examples and sensitivity analysis are provided to demonstrate the proposed model

economic order quantity models for imperfect items with buy and repair options abstract one of the celebrated extensions of the economic order production quantity eoq epq model is one that assumes a received shipment contains a fraction of imperfect non conforming quality items where these items detected by 100 screening are sold as a single batch at a discounted price this paper revisits this model salameh and jaber 2000 int j prod econ 64 1 59 64 and extends it by assuming that a shipment is coming from a distant supplier and therefore it is not feasible to replace the imperfect items with an additional order to the same supplier to address this restriction two models are presented the first assumes that imperfect items are sent to a repair shop who charges a cost plus a markup margin while the second model assumes that imperfect items are replaced by good ones from a local supplier at a higher cost the inventory environment assumed in this paper is relevant in todays globalised supply chains thus practical implications of the problem faced are discussed numerical results are also presented and discussed the results show that there exists a threshold value of the unit purchase cost of an emergency ordered item and a fraction of defectives to which it is decided to either buy or repair

note on economic production quantity model for items with imperfect quality a practical approach abstract in this note we present a simple approach for determining the economic production quantity for an item with imperfect quality we compare the results based on the simple approach with the optimal method for determining the lot size and show that almost optimal results are obtained using the simple approach

competitive nonlinear tariffs abstract this paper generalizes the study of nonlinear tariffs i e those depending nonlinearly on the quantity purchased to the case of a symmetric oligopoly competitive equilibria and the corresponding tariffs are analyzed in a cournot framework various equilibria are obtained which depend both upon the number of competing suppliers and the choice of market parameters used to characterize the competitors strategies buyers are classified by type each selecting an optimal consumption level in response to the prevailing tariff the phenomena of buyer self selection found in monopoly nonlinear pricing and the scaling of equilibrium demand elasticity found in cournot models both appear in the results

a multi item fuzzy economic production quantity problem with a finite production rate abstract inventory management and production planning are essential tasks for every company in the industry therefore the development of a large set of economic order quantity eoq models is needed in this paper a fuzzy multi item economic production quantity epq model is developed this paper contributes to the state of the art with a theoretical study of a problem where a company has to decide the size of some production batches under uncertain cycle times the uncertainty will be handled with triangular fuzzy numbers and an analytical solution will be found to the optimization problem

are developing countries really defying the embedded liberalism compact this study evaluates the embedded liberalism hypothesis in a broad swath of less developed countries ldc s the authors find that ldc governments pursue a distinct welfare state policy that protects citizens from economic insecurities associated with global market expansion specifically governments use public employment and particularly employment in civil services and administration to foster domestic stability alongside market expansion however such jobs are targeted to politically salient groups not poorer groups that might also face increased economic uncertainty postopenness in turn public employment shores up public support for openness the authors findings suggest that free traders have reasons both to celebrate and to bemoan this ldc embedded liberalism compact on the positive side ldc governments are working hard to maintain political support for free trade on the other hand the compromise of protecting privileged groups at the expense of others in society raises questions about the long term sustainability of their strategy

openness external risk and volatility implications for the compensation hypothesis a central assumption in the globalization literature is that economic openness generates economic insecurity and volatility based on this assumption schol ars of international political economy have proposed the compensation hypothesis which claims that globalization bolsters rather than undermines the welfare state by increasing public demand for social protection against externally generated eco nomic instability the openness volatility link is dubious however on both theoret ical and empirical grounds in this study i revisit the volatility assumption focusing on a crucial difference between openness and external risk in their effect on volatil ity my statistical analysis of a panel data set from 175 countries 1950 2002 finds a consistent effect of external risk on volatility of the major economic aggregates but a largely insignificant effect of openness these findings suggest that economic volatility may be a mistaken link in explaining the openness spending nexus calling for further research on the causal mechanisms linking the two the general growth of government in the post world war ii era is one of the most important empirical regularities in political science measured by general govern ment consumption or sectoral expenditures government size grew dramatically during most of the postwar period intrigued by this phenomenal government growth political scientists offered numerous accounts some viewing this growth as a corollary of economic phenomena such as modernization industrialization income distribution or fiscal illusion and others attributing government growth to political causes such as bureaucratization interest group politics and electoral competition 1

a generalized quantity discount pricing model to increase supplier s profits in this paper the joint problem of ordering and offering price discount by a supplier to his sole major buyer is analyzed the objective is to induce the buyer to alter his order schedule and size so that the supplier can benefit from lower set up ordering and inventory holding costs we generalize the quantity discount pricing model of monahan monahan j p 1984 a quantity discount pricing model to increase vendor profits management sci 30 6 720 726 to 1 explicitly incorporate constraints imposed on the amount of discount that can be offered and 2 relax the implicit assumption of a lot for lot or order for order policy adopted by the supplier an algorithm is developed to solve the supplier s joint ordering and price discount problem

long run competition in capacity short run competition in price and the cournot model in this article we investigate the nature of equilibrium in markets in which firms choose the scale of operation before they make pricing decisions we analyze a duopoly model in which firms choose their capacities before engaging in bertrand like price competition we demonstrate that the cournot outcome is unlikely to emerge in such markets and that the equilibrium tends to be more competitive than the cournot model would predict in addition our results indicate a tendency toward asymmetric firm sizes and price dispersion that results from the mixed strategies firms use in equilibrium

efficient inventory control for imperfect quality items in this paper we present a general eoq model for items that are subject to inspection for imperfect quality each lot that is delivered to the sorting facility undertakes a 100 per cent screening and the percentage of defective items per lot reduces according to a learning curve the generality of the model is viewed as important both from an academic and practitioner perspective the mathematical formulation considers arbitrary functions of time that allow the decision maker to assess the consequences of a diverse range of strategies by employing a single inventory model a rigorous methodology is utilised to show that the solution is a unique and global optimal and a general step by step solution procedure is presented for continuous intra cycle periodic review applications the value of the temperature history and flow time through the supply chain is also used to determine an efficient policy furthermore coordination mechanisms that may affect the supplier and the retailer are explored to improve inventory control at both echelons the paper provides illustrative examples that demonstrate the application of the theoretical model in different settings and lead to the generation of interesting managerial insights

eoq models for a coordinated two level international supply chain considering imperfect items and environmental impact abstract for a two level supply chain models are presented to determine the optimal production shipment policy for items with imperfect quality in three different scenarios a both the vendor and the buyer are in the same country b the vendor and the buyer are in different countries where the stochastic behavior of the exchange rate between the two countries is modeled using a mean reverting process and c environmental impact is incorporated in determining the optimal production shipment policy by taking into account the fixed and variable carbon emission costs the objective is to minimize the total expected cost per unit time for each scenario considering equal shipment size the total expected cost per unit time is derived and the solution procedure is proposed numerical examples are presented and the results are discussed

designing a firm s coordinated manufacturing and supply decisions with short product life cycles in this paper we consider a problem of joint coordination between a firm s manufacturing and supply departments the manufacturing department is responsible for meeting random demand of a product with a short life cycle the supply department s responsibility is to provide the sufficient amount of raw materials so that the required production level can be achieved when coordination prevails both departments decisions are jointly made otherwise decisions are made independently without an exchange of information if the random demand exceeds the amount produced a second production run can be expedited at a substantially higher cost our analysis yields insightful results to such a coordination problem between the two departments we provide conditions under which it is desirable to coordinate resulting in a significant increase in expected profit if coordination is optimal then the supply department would purchase additional reserved material for the second run under this scenario we analyze the effects of joint coordination on the expected profit we also find explicit conditions for which joint coordination is not beneficial i e the supply department should only order sufficient material to meet the first production run requirements we provide a detailed set of numerical examples and generate response surfaces indicating the desirability of coordination for different pairs of parameter combinations

managing channel profits a channel of distribution consists of different channel members each having his own decision variables however each channel member s decisions do affect the other channel members profits and as a consequence actions a lack of coordination of these decisions can lead to undesirable consequences for example in the simple manufacturer retailer consumer channel uncoordinated and independent channel members decisions over margins result in a higher price paid by the consumer than if those decisions were coordinated in addition the ensuing suboptimal volume leads to lower profits for both the manufacturer and the retailer this paper explores the problems inherent in channel coordination we address the following questions what is the effect of channel coordination what causes a lack of coordination in the channel how difficult is it to achieve channel coordination what mechanisms exist which can achieve channel coordination what are the strengths and weaknesses of these mechanism what is the role of nonprice variables e g manufacturer advertising retailer shelf space in coordination does the lack of coordination affect normative implications from in store experimentation can quantity discounts be a coordination mechanism are some marketing practices actually disguised quantity discounts we review the literature and present a simple formulation illustrating the roots of the coordination problem we then derive the form of the quantity discount schedule that results in optimum channel profits this article was originally published in marketing science volume 2 issue 3 pages 239 272 in 1983

an eoq model with random variations in demand this paper presents a model that incorporates variations in the demand rate at random time points into the inventory planning decision these changes in demand may occur due to economic recessions labor strife starting or ending or other events that result in a period of time during which the rate of demand is shifted up or down from its current level the paper uses system point level crossing theory to derive expressions for the distribution and expected value of on hand inventory ordering rate and the expected total cost rate for a given ordering policy a sensitivity analysis is conducted and a number of qualitative properties are provided to illustrate the use of the results to obtain optimal order quantities

an economic order quantity model with defective items and shortages abstract the fundamental assumption of an economic order quantity eoq model is that 100 of items in an ordered lot are perfect this assumption is not always pertinent for production processes because of process deterioration or other factors this paper develops an eoq model for that each ordered lot contains some defective items and shortages backordered it is assumed that 100 of each lot are screened to separate good and defective items which are collection of imperfect quality and scrap items the effect of percentage defective on optimal solution is studied while numerical examples are provided for the developed model

an approach for developing an optimal discount pricing policy this paper addresses the problem of why and how a seller should develop a discount pricing structure even if such a pricing structure does not alter ultimate demand the situation modeled is most appropriate where the seller s product does not represent a major component of the buyer s final product where the demand for the product is derived or where the price is only one of many factors considered in making a purchase decision a model of buyer reaction to any given pricing scheme is developed to show that there exists a unified pricing policy which motivates the buyer to increase its ordering quantity per order thereby reducing the joint buyer and seller ordering and holding costs as a result the seller is able to reduce its costs while leaving the buyer no worse off and often better off the model is extended to handle variable ordering and shipping costs and situations where the seller faces numerous groups of buyers each having different ordering policies finally a case study is presented explicitly showing how the proposed pricing policy can be applied to the situation of a large seller selling to a number of different buyer groups

an eoq model with imperfect quality items inspection errors shortage backordering and sales returns abstract in practice the items received in a lot may contain defective items and the screening process to eliminate the defective items may involve both a type i and a type ii error due to the defective items and the inspection errors shortages may sometimes occur in this paper we develop an economic order quantity model with imperfect quality items inspection errors shortage backordering and sales returns a closed form solution is obtained for the optimal order size the maximum shortage level and the optimal order reorder point if shortages are not allowed we adopt the order overlapping scheme proposed by maddah et al 2010 computers and industrial engineering 58 4 691 695 to develop an eoq model to prevent shortages during the screening process numerical examples show the impacts of the defective probability the inspection errors and the holding and backordering costs on the optimal solution

on the detection of collusion and predation abstract this lecture not only shows how game theory can contribute to the detection of collusion and predation but also how experts for the defense can use game theoretic arguments to make such detection difficult a few important european anti trust cases are discussed to illustrate

government assisted oligopoly coordination a concrete case in 1993 the danish antitrust authority decided to gather and publish firm specific transactions prices for two grades of ready mixed concrete in three regions of denmark following initial publication average prices of reported grades increased by 15 20 percent within one year we investigate whether this was due to a business upturn and or capacity constraints but argue that these seem to have little explanatory power we conclude that a better explanation is that publication of prices allowed firms to reduce the intensity of oligopoly price competition and hence led to increased prices contrary to the aim of the authority

collusive equilibrium in the great salt duopoly this paper uses data presented in a report of the monopolies and mergers commission on the market for white salt to test the implications of some recent developments in oligopoly theory the market in question is a homogeneous price setting duopoly where firms are subject to capacity constraints we find that the conclusions of models based on one shot non cooperative games do not hold collusion in the market is readily explained by the types of threat strategies underlying abreu s simple penal codes possible explanations of the collusive equilibrium in terms of joint profit maximization are not supported by the data indeed the explanation of the equilibrium remains an open question copyright 1993 by royal economic society

looking at the cost side of monopoly welfare loss under oligopoly is defined as that part of consumer surplus which is lost and not regained by higher profits in a model with asymmetric firms this implies that the total welfare loss consists of the deadweight loss triangle plus a cost side inefficiency effect due to the fact that in imperfect markets not all firms utilize the lowest cost technique using a flexible cv model we calculate these effects empirically for two relatively homogeneous industries pulp paper and cement the deadweight loss triangles are shown to be smaller than the cost difference effect the staircase for these industries

disaggregation and consolidation of imperfect quality shipments in an extended epq model abstract we consider a standard economic production quantity epq model due to manufacturing variability a fraction p of the produced inventory will have imperfect quality where p is a random variable with a known distribution we consider a 100 inspection policy and further assume that the inspection rate is larger than that of production thus all imperfect quality items will be detected by the end of the production cycle for such an augmented epq model we first derive the new optimal production quantity assuming that the imperfect quality items are salvaged once at the end of every production cycle then we extend this base model to allow for disaggregating the shipments of imperfect quality items during a single production run finally we consider aggregating or consolidating the shipments of imperfect items over multiple production runs under both scenarios we derive closed form expressions for both the economic production quantity and the batching policy and show that our desegregation consolidation schemes can lead to significant cost savings over the base model

optimal lot sizing integration policy under learning and rework effects in a manufacturer retailer chain abstract most research in economic manufacturing order quantity management assumes that all products are of perfect quality and are produced at a constant production rate one result of this assumption is that the number of units produced in a given period is constant which is not the case in real life most production systems produce items which are of perfect quality along with some that are of imperfect quality defective items as well as the learning effect affect production and inventory costs thereby shaping the performance of the manufacturer retailer chain the present study uses the nash stackelberg and cooperation games to model an imperfect production system to investigate the combined effects of lot sizing size integration the learning effect imperfect production and the rework process on a manufacturer retailer channel this study also demonstrates the optimal properties of the proposed models develops a search algorithm for obtaining optimal solutions and conducts a numerical study to seek structural and quantitative insights into the structure of the proposed models in addition it analyzes the sensitivity of the solutions in relation to the major parameters

trade and insurance with imperfectly observed outcomes abstractthe following sections are included introductionthe modelunobserved outcomescostly observationconcluding remarksreferences this abstract was borrowed from another version of this item

do more open economies have bigger governments another look abstract we reconsider the evidence of a positive relationship between openness and the size of government recently established by rodrik rodrik d 1998 why do more open economies have bigger governments journal of political economy 106 997 1032 and others while the existing literature focuses on expenditure based measures of government we consider non budgetary measures such as government ownership of enterprises price controls asset expropriation each of these may have little impact on government expenditures yet can make the role of government sizable we demonstrate that the scope of government is much larger in less open economies when considering non budgetary measures additionally we show that higher levels of non budgetary government are positively correlated with trade barriers finally we provide further evidence on the hypothesis that larger governments provide social insurance in open economies subject to terms of trade shocks although we find that greater terms of trade risk is weakly associated with larger government in all forms these interventions include price controls and greater risk of asset expropriation which are hard to reconcile with a pure insurance motive

epq models with varying setup cost abstract in this paper the classical economic production quantity epq model is generalized by considering a relationship between the setup cost and the production run length the dependency between the setup cost and run length can be related to process deterioration and learning and forgetting effects two models are developed the first of which is for the case when shortages are not allowed and the other one permits shortages the cost functions associated with these models are proved to be convex and optimal solutions are determined results show that the relationship between setup cost and production run length has a significant impact on the optimal lot size and average total cost in the epq model numerical examples are presented to demonstrate the utility of the models

celebrating a century of the economic order quantity model in honor of ford whitman harris abstract this writing presents a brief introduction to the papers included in the special issue celebrating a century of the economic order quantity model in honor of ford whitman harris published by the international journal of production economics forty one papers covering an extensive scope of inventory management have been incorporated in this volume from contributing authors from 20 countries located in america asia europe and africa this special issue also provides a basis for new directions in inventory management research

eoq with a correlated binomial supply abstract this paper considers a variant of the economic order quantity eoq model under random supply a binomial supply model is adopted where every item received is of imperfect quality with the same probability we study the realistic case where the qualities of items in an order are correlated and draw useful insights the most interesting of which is that correlation decreases the order size several practical correlation patterns are investigated and discussed we also show that several commonly used models in the literature can be represented by an equivalent correlated binomial supply model

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

international trade foreign investment and the formation of the entrepreneurial class in this paper i examine the argument that free trade may be harmful to less developed countries because such international competition inhibits the formation of a local entrepreneurial class i view the entrepreneur as the manager of the industrial enterprise as well as the agent who bears the risks associated with industrial production a two sector model of a small open economy is developed in which the size of the entrepreneurial class is endogenous it is shown that the entrepreneurial class is smaller under free trade than would be first best optimal in the presence of efficient risk sharing institutions such as stock markets nonetheless there are potential gains from trade and any protectionist policy that increases the number of entrepreneurs will have deleterious welfare consequences this abstract was borrowed from another version of this item

price competition in a capacity constrained duopoly abstract this paper characterizes the set of nash equilibria in a model of price setting duopoly in which each firm has limited capacity and demand is continuous and decreasing in general there is a unique equilibrium so that comparative static exercises are meaningful the properties of the equilibrium conform with a number of stylized facts the equilibrium prices are lower the smaller is demand relative to capacity when demand is in an intermediate range the firms use mixed strategies they randomly hold sales if capacities are chosen simultaneously before prices the set of equilibrium capacities coincides with the set of cournot quantities

trade and insurance with moral hazard abstract previous literature on the use of trade policy for insurance has relied implicitly on moral hazard and adverse selection as the reasons for the failure of private markets for risk bearing this paper begins with the observation that such forces should be incorporated explicitly into the models to ensure a fair comparison between markets and governments for the case of moral hazard it is found that market equilibrium given exclusive insurance is an informationally constrained pareto optimum in one case of non exclusive insurance a systematic role for government insurance is found but the scope of trade policy is ambiguous

economic insecurity and social policy expansion evidence from interwar europe what is the impact of economic insecurity on the development of institutions of social insurance existing studies have examined this question by exploring the impact of various measures of economic volatility on aggregate government expenditures or revenues these aggregate data are however an imperfect proxy of the character of institutions of social protection to overcome the limitations of earlier studies this article explores the conditions under which economic insecurity leads to the extension of the level of social insurance coverage i argue that economic insecurity sharpens a sectoral cleavage between coalitions in high risk and low risk sectors workers and some employers in high risk sectors will favor the introduction of social insurance institutions characterized by broad levels of coverage and a high redistribution of costs across occupations in contrast a cross class alliance in low risk sectors will oppose proposals aiming at the introduction of redistributive social policies fearing that these policies will turn them into subsidizers of high risk industries a redistributive social insurance policy will be introduced only if the high risk coalition is larger the article tests both the micro and macro level implications of this theory by examining the development of unemployment insurance policies in interwar europe i gratefully acknowledge comments from carles boix peter gourevitch and two anonymous referees many thanks to stefano bartolini john fitzgerald and michael tomz for sharing data with me

how many parts to make at once reprinted from factory the magazine of management volume 10 number 2 february 1913 pp 135 136 152 interest on capital tied up in wages material and overhead sets a maximum limit to the quantity of parts which can be profitably manufactured at one time set up costs on the job fix the minimum experience has shown one manager a way to determine the economical size of lots

an optimal policy for a single vendor single buyer integrated production inventory problem with process unreliability consideration abstract this article develops a model to determine an optimal integrated vendor buyer inventory policy for flawed items in a just in time manufacturing environment the objective is to minimize the total joint annual costs incurred by the vendor and the buyer the production process is assumed to deteriorate during processing and produces a certain number of defective items for practical purpose the article is concerned with the policy in which the delivery quantity to the buyer is identical at each replenishment the expected annual integrated total cost function is derived and a solution procedure is established to find out the optimal solution finally the solution technique is illustrated with a numerical example available in the literature

a century of evolution from harris s basic lot size model survey and research agenda abstract determining the economic lot size has always represented one of the most important issues in production planning this problem has long attracted the attention of researchers and several models have been developed to meet requirements at minimum cost in this paper we explore and discuss the evolution of these models during one hundred years of history starting from the basic model developed by harris in 1913 up to today following harris s work a number of researchers have devised extensions that incorporate additional considerations the evolution of eoq theory strongly reflects the development of industrial systems over the past century here we outline all the research areas faced in the past by conducting a holistic analysis of 219 selected journal papers and trying to give a comprehensive view of past work on the eoq problem finally a new research agenda is proposed and discussed

performance in a hostile world economic growth in capitalist democracies 1974 1982 many recent studies argue that labor organization and government partisanship were important determinants of the economic performance of the advanced industrial democracies during stagflation they do not however take into account the potential impact on performance of position in the international economy the relationships reported may therefore be largely spurious even when the strong effects of international position most notably the extent of dependence on imported sources of oil were controlled for domestic political structures remained powerful determinants of economic performance during stagflation corporatist political economies dominated by leftist governments in which labor movements were densely and centrally organized and market political economies in which labor was much weaker and rightist governments were predominant performed significantly better than the less coherent cases in which the power of labor was distributed asymmetrically between politics and the market

lot sizing with a markov production process and imperfect items scrapped abstract this paper considers an inventory system within the economic order quantity eoq model framework under random supply the production process can go out of control with a constant probability and start producing imperfect quality items such a system has been studied in the literature under the assumption that defective items are reworked instantaneously and returned to inventory in some situations imperfect quality items are not necessarily defective and are removed from the inventory to be used elsewhere this paper develops two models where imperfect items are removed from inventory the first model finds the expected cost and optimal lot size assuming that imperfect quality items are removed from inventory at no cost the second model assumes that batches of imperfect quality are consolidated and shipped together due to economies of scale in shipping analytical and numerical results are developed for both models revealing several managerial insights

an imperfect production process in a volume flexible inventory model abstract this paper hypothesizes an imperfect production inventory system where the items produced are a mixture of perfect and imperfect quality some of the imperfect quality items can be sold at a reduced selling price the unit production cost is taken to be a function of the finite production rate which is treated as a decision variable the mathematical expression for the expected profit function is derived and it is maximized subject to different constraints of the system using interior penalty function method for constrained optimization the algorithm of which is given the solution procedure is illustrated with the help of numerical examples the sensitivity of each variable to changes in the values of the parameters of the system is examined lastly various issues conforming the system are discussed

an integrated production inventory model with imperfect production processes and weibull distribution deterioration under inflation abstract this study develops an integrated production and inventory model from the perspectives of both the manufacturer and the retailer the model assumes a varying rate of deterioration partial backordering inflation imperfect production processes and multiple deliveries the elapsed time until the production process shift is assumed to be arbitrarily distributed the discounted cash flow and classical optimization technique are used to derive the optimal solution a numerical example including the sensitivity analysis is given to validate the results of the production inventory model the integrated decision results in lower optimal joint cost compared with an independent decision by the manufacturer and the retailer

coordinating pricing and production decisions in the presence of price competition abstract in this paper we study the effects of coordinating pricing and production decisions on the improvement of a firm s position in a price competitive environment assuming duopolistic market conditions we use game theoretic concepts and models to analyze two scenarios a firm s marketing and production departments may vertically coordinate their pricing and production quantity decisions and the two firms may horizontally compete for price sensitive random demand the two scenarios include i no coordination and ii coordination in both firms we show that by coordinating their pricing and production decisions competing firms can increase their profitability especially when conditions are unfavourable i e with smaller market sizes higher unit costs and lower unit revenues while it may be intuitive to expect that coordination will outperform non coordination our models provide a means for formalizing and quantifying the differences between the two policies

optimal fiscal policy and different degrees of access to international capital markets abstract empirically the cyclical pattern of fiscal policy differs between developed and developing countries with in particular much greater pro cyclicality and volatility of public investment in developing countries in this paper i provide a theoretical explanation for the observed differences by analyzing optimal fiscal policy under different degrees of access to world capital markets if the supply of foreign capital is elastic as in a developed country then it is optimal to adjust to an adverse external shock by borrowing from abroad to finance public expenditure and cutting taxes to smooth private consumption if the supply of foreign capital is inelastic however as in a developing country the optimal adjustment policy is to reduce public investment by much more than public consumption and to raise consumption taxes

the economic order quantity model revisited an extended exergy accounting approach abstract the economic order quantity eoq model has been popular among academicians and practitioners for decades despite the many variants of the eoq that have appeared in the literature to fine tune it to reality it still has limitations a major one is that it does not take into account the hidden costs inherent in inventory systems some of these costs relate to sustainability issues including environmental social labor and economic effects this paper considers some of these costs referred to as the exergetic costs and estimates them using the extended exergy accounting eea approach extended exergy accounting assigns equivalent exergetic values to capital labor and environmental remediation costs of a system the analysis combines the classical exergy analysis with the sustainability factors which are the labor capital and environment the paper uses an exergetic model to determine the eoq inventory policies for three firms operating in the usa germany and china the results show that the eoq is different for the three firms because the equivalent exergy of capital labor and environment remediation costs is different in each country

an eoq model with backorders and rejection of defective supply batches abstract we consider a single echelon inventory installation under the classical eoq with backorders paradigm to study the effects of supply quality on cost performance previous research on imperfect supply quality has focused on variants of the proportional deterministic or random yield problem where supply batches are all accepted and then used after screening any defects in this paper we study an alternative setting where entire supply batches may be defective below quality standards and therefore rejected on arrival note that such supply flow disruptions are analogous to those considered within the economic order quantity with disruptions eoqd area of research we first present an exact model for the system expected cost and show its convexity optimal cost and respective values of the decision variables i e planned order quantity and backorders are then obtained in a closed form interestingly under perfect supply quality all expressions reduce to those of classical eoq analytical and computational results reveal the serious impact of inferior supply quality on system cost as well as the sensitivity of the system parameters

tacit collusion with imperfect monitoring in the canadian manufacturing industry an empirical study this article undertakes a cross sectoral analysis of a salient empirical implication of the model of tacit collusion advanced by abreu pearce and stachetti 1986 specifically we assess the prevalence of a first order markovian process for alternating between price wars and collusive periods through nonparametric tests the analysis focuses on 30 different industries in canada the evidence provides weak support for optimal collusion in one industry which is consistent with the idea that such kind of collusive arrangements is unusual or if collusion is all too common that price wars as deviations from collusion are rare

optimal lot sizing in an imperfect production system with homogeneous reworkable jobs abstract we consider a lot sizing problem in a single stage imperfect production system where the job processing is failure prone the processing may generate two types of defects 1 reworkable defects which must be sent back for rework 2 nonreworkable defects which are discarded immediately the production process will switch between new jobs and rework jobs both new job processing time and rework time are random we discuss the optimal lot sizing control under a class of operating policies to maximize the average profit over an infinite time horizon we establish the existence of an optimal lot size furthermore we characterize the profit function through the discussion we obtain a very efficient algorithm for determining an optimal lot size

optimal vendor investment for reducing defect rate in a vendor buyer integrated system with imperfect production process this paper investigates a single vendor single buyer integrated production inventory model with stochastic demand and imperfect production process it is assumed that there is an inspection activity on the part of the buyer with a fixed screening rate greater than the demand rate the vendor invests money in order to improve the production process quality and reduce the number of defectives the expected annual integrated total cost is derived under the n shipment policy and an iterative procedure is suggested to determine the optimal decisions the benefit of investment in reducing the defect rate is illustrated by way of numerical examples it is observed that the higher the defect rate the more beneficial the investment numerical studies further explore that an increased demand requires an increased investment to optimize the total cost

economic production quantity model for items with imperfect quality abstract the assumptions necessary to justify the use of economic production quantity epq eoq models are rarely met to provide mathematical models that more closely conform to actual inventories and respond to the factors that contribute to inventory costs the models must be extended or altered this paper hypothesizes a production inventory situation where items received or produced are not of perfect quality items of imperfect quality not necessarily defective could be used in another production inventory situation that is less restrictive process and acceptance control the electronics industry gives good examples of such situations this paper extends the traditional epq eoq model by accounting for imperfect quality items when using the epq eoq formulae this paper also considers the issue that poor quality items are sold as a single batch by the end of the 100 screening process a mathematical model is developed and numerical examples are provided to illustrate the solution procedure

risk and trade regimes another exploration an analysis of a small sample of countries shows that the higher the level of termsof trade risk that a nation faces in international markets the more likely it is to increase barriers the analysis also shows that the greater the availability of social insurance programs mounted by a nation s government the less likely it is to block free trade in comparison with the small open economies of western europe therefore developing countries may remain protectionist because they lack the resources to mount internal programs of transfer payments as a means of coping with risk from international markets

economic production quantity model for items with imperfect quality subject to learning effects abstract salameh and jaber 2000 international journal of production economics 64 59 64 developed an inventory situation where items received are not of perfect quality defective and after 100 screening imperfect quality items are withdrawn from inventory and sold at a discounted price this paper extends the work of salameh and jaber by assuming the percentage defective per lot reduces according to a learning curve which was empirically validated by data from the automotive industry mathematical models are developed with numerical examples provided and discussed the developed model was compared with the model of salameh and jaber to emphasize the importance of learning

economic order quantity for items with imperfect quality revisited abstract we rectify a flaw in an economic order quantity eoq model with unreliable supply characterized by a random fraction of imperfect quality items and a screening process developed by salameh and jaber 2000 economic production quantity model for items with imperfect quality international journal of production economics 64 1 3 59 64 this leads to simple expressions of the optimal order quantity and expected profit per unit time we then analyze the effect of screening speed and variability of the supply process on the order quantity and show that the order quantity in our model is larger than that of the classical eoq model when the variability of the yield rate is reasonably low in addition we extend the model by allowing for several batches of imperfect quality items to be consolidated and shipped in one lot this is likely to be useful when there are economies of scale in shipping of imperfect quality items finally we present numerical results to illustrate the application of the model and draw insights

social protection around the world external insecurity state capacity and domestic political cleavages this article develops and tests a political model specifying the conditions under which external risk leads to the introduction of redistributive social policies and argues that external risk sharpens a domestic political cleavage over the design of institutions of social insurance workers in sectors facing high volatility of income will support the introduction of social policies characterized by broad levels of insurance coverage and high redistribution of costs across occupations whereas workers in low risk sectors will oppose redistributive social policies the strength of preexisting state institutions also affects policy preferences of various sectors in the presence of weak ineffective states that are unable to collect social insurance contributions from sectors that are net contributors to the system high risk sectors will find redistributive social policies unattractive the article tests predictions of the model using new measures of the level of social insurance coverage in more than 100 c

three echelon supply chain coordination considering duopolistic retailers with perfect quality products abstract this paper explores channel coordination and profit division issues of a manufacturer distributer duopolistic retailers supply chain for a product where the manufacturer supplies lotsize of the product that contains a random portion of imperfect quality item in manufacturer stackelberg vertical game setting the duopolistic retailers three behaviours cournot collusion and stackelberg are discussed besides analyzing the effect of imperfect quality product on optimal decisions the paper depicts the hybrid contract mechanism so that all units quantity discount with franchise fee resolves channel conflict though unable to provide win win outcome for surplus profit division the paper proposes two sequential bargaining processes backward and forward where outcome of a nash bargaining is dependent on the previous it is found that for channel coordinated win win profit the manufacturer prefers collusion stackelberg and cournot while the retailer prefers the reverse and both prefer backward sequential bargaining but the distributers preference depends on the target profit that it sets during the bargaining process the proposed mechanisms are illustrated by a numerical example

supplier pricing and lot sizing when demand is price sensitive abstract the problem of co ordination between a vendor and a buyer is formulated as a two person fixed threat bargaining game the vendor decides on his lot size and the price schedule he is to offer to the buyer the buyer decides upon his lot size and the selling price in the market we have characterized pareto efficient solutions and the nash bargaining solution for the problem we have also proposed two pricing schedules for the vendor who is supplying to a large population of buyers the first one is based upon profit sharing the second one resembles the classical all unit quantity discount schedule we have thus provided for the supplier a procedure for setting all unit quantity discount schedule

economic ordering quantity models for items with imperfect quality abstract in this paper we first look at the issue of non shortages in models with proportional imperfect quality when the proportion of the imperfects is a random variable more specifically we revisit the papers of salameh and jaber int j prod econom 64 2000 59 and chan et al prod plann control 14 2003 588 and we point out that the sufficient conditions given in these papers to ensure that shortages will not occur may not really prevent their occurrence next considering the timing of withdrawing the imperfect quality items from stock we clarify a point not clearly stated in salameh and jaber int j prod econom 64 2000 59 and we extented this model to the case in which withdrawing takes place at the end of the planning horizon finally we establish that the objective of maximizing the mean average profit which was set in salameh and jaber int j prod econom 64 2000 59 is superfluous and the results given there can be obtained by ignoring the revenue issues assumed in the model and minimizing directly the mean average cost

economic order quantity for growing items abstract economic order production quantity eoq epq models have generally been presented for manufacturing products incorporating some important features of a specific category of products different eoq epq models have been proposed in literature this study proposes a new class of inventory models i e a model for a specific type of inventory items growing items poultry and livestock are good examples of growing inventory items we begin by proposing a general mathematical model which can be used for different types of growing items followed by a particular mathematical model for a specific type of poultry we calculate the optimal order quantity of the growing items at the start of a growing cycle the optimal length of the growing cycle and the optimal total profit numerical examples are provided for a type of poultry to illustrate the model a sensitivity analysis is presented to study the effect of the main parameters of the model in terms of its decision variables and objective function the results of the sensitivity analysis suggest that production costs are the most crucial parameter

optimal penal codes in price setting supergames with capacity constraints this paper constructs optimal pure strategy penal codes for a broad class of symmetric bertrand supergames with capacity constraints the results should simplify the analysis of bertrand supergames because the punishments comprising the penal codes constructed below have a very simple form and the associated payoffs are often easy to calculate it is also shown that for a commonly employed subclass of the games considered the admission of mixed strategies does not allow severer punishments the analysis draws heavily on the pathbreaking work of abreu 1984 he demonstrated that in the search for optimal penal codes attention can be restricted to simple penal codes simple penal codes are characterized by a vector of outcome paths one for each player the ith outcome path is interpreted as the punishment to be imposed on the ith player if he deviates from the equilibrium path or from any punishment path section 2 explains the basic framework of analysis the class of bertrand games studied is very general no particular rationing rule is imposed some mild restrictions are placed on the firms sales functions instead the commonly used models of levitan and shubik 1972 and beckman 1965 are special cases of the games analysed below it is assumed throughout that there is a price firms can be induced to charge if the punishment for charging a different price gives the offending firm a payoff equal to its security level for the supergame thus either there must exist a static nash equilibrium in pure strategies or else the discount factor must not be too close to zero in section 3 optimal penal codes are constructed and it is established that the punishments comprising them always drive punished firms to their security levels the arguments employed make clear that optimal penal codes are not generally unique this issue is addressed in section 4 where it is also shown that the levitan shubik rationing rule exhibits more types of optimal penal codes than do other rules in particular if the levitan shubik rule is employed then punishments that are analogous to abreu s 1986 symmetric two phase punishments for cournot games can be used to construct optimal penal codes in bertrand games this property does not hold generally however

economic order quantity model for items with imperfect quality with learning in inspection abstract the economic order quantity eoq model is the simplest and earliest inventory model in the literature its simple mathematics is attributed to its assumptions which are rarely met salameh and jaber 2000 economic production quantity model for items with imperfect quality int j prod econ 64 59 64 addressed one of these assumptions that items received or produced are not of perfect quality this paper extends salameh and jaber s work for the case where there is learning in inspection the model is realistic in that it considers situations of lost sales and backorders mathematical models are developed with numerical examples provided and results discussed for the cases of i partial transfer of learning ii total transfer of learning and iii no transfer of learning

tariffs as insurance optimal commercial policy when domestic markets are incomplete free trade is not optimal for a small country that faces uncertain terms of trade if some factors are immobile ex post and markets for contingent claims are incomplete the government can improve social welfare by using commercial policy that serves as a partial substitute for missing insurance markets using a combination of analytical and simulation techniques we demonstrate that optimal policy for this purpose will often have an anti trade bias we also show that the usual preference by economists for factor or product taxes and subsidies over tariffs and export subsidies may not be justified in this context this abstract was borrowed from another version of this item