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

trade liberalization and wage inequality abstract this paper studies empirically the link between trade liberalization and wage inequality in chile within the context of the heckscher ohlin samuelson hos model we use cointegration techniques to estimate the long run relationship between the skill premium in chile and product prices openness and factor endowments we find that the fall in the relative price of labor intensive goods helps explaining the increase in wage inequality in chile during the last two decades the increase in proportion of the labor force with college degree on the other hand tends to reduce wage inequality in chile openness measured as the volume of trade over gdp widens the wage gap between skilled and unskilled labor we offer some hypothesis on the elements that are behind this positive relationship between wage openness and inequality but no empirical work is done this area may be an interesting subject of research

optimal ordering and pricing policies in a single period environment with multivariate demand and markdowns this paper investigates a single period inventory model in which the demand of the product is a deterministic multivariate function of price time and level of inventory models are formulated for the basic pricing case and the case with a price markdown during the season solution methodologies are presented for each case when the pricing decisions are predetermined and when they are decision variables comments on the practical use of this model are presented and sensitivity analysis is conducted on the decision variables and demand parameters

optimal ordering for a probabilistic one time discount abstract we develop a model for a one time special purchasing opportunity where there is uncertainty with respect to the materialization of the discounted purchasing offer our model captures the phenomenon of an anticipated future event that may or may not lead to a discounted offer we analyze the model and show that the optimal solution results from a tradeoff between preparing for the special offer and staying with the regular ordering policy we quantify the tradeoff and find that the optimal solution is one of four intuitive policies we present numerical illustrations that provide additional insights on the relationship between the different ordering policies

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

trade liberalization and rising wage inequality in latin america reconciliation with hos theory abstract the paper puts forward the hypothesis that the transitory effects of trade liberalization on wage inequality can differ from the long run outcome in cases where the hos theory predicts a decline in wage inequality in the long run a temporary rise can nevertheless occur due to i the asymmetries in the speed of contraction in the import sector and expansion in other sectors and ii the capital skill complementarity in production the asymmetric contraction and expansion causes a transitory capital accumulation that boosts the relative and the real wage of skilled labor due to capital skill complementarity although the long run hos fundamentals are therefore dominated in the short run by the transient effects arising due to capital skill complementarity the observed rise in wage inequality is nonetheless consistent with the hos theory appropriately extended to a dynamic setting

openness and wage inequality in developing countries the latin american challenge to east asian conventional wisdom the experience of east asia in the 1960s and 1970s supports the theory that greater openness to trade tends to narrow the wage gap between skilled and unskilled workers in developing countries in latin america since the mid 1980s however increased openness has widened wage differentials this conflict of evidence is probably not the result of differences between east asia and latin america instead the conflict is probably the result of differences between the 1960s and the 1980s specifically the entry of china into the world market and perhaps the advent of new technology biased against unskilled workers

optimal lot size for a production inventory system with partial backlogging and mixture of dispatching policies abstract in this paper we study a production inventory model for a single product where shortages are partially backlogged both the backorder cost and the lost sale cost depend on a fixed cost and a cost proportional to the shortage time we assume a mixture between the dispatching policies known as lifo last in first out and fifo first in first out in the discipline of service to fill the backlogged demand by using a sequential optimization procedure we determine in a closed form the optimal production policies and the optimal profit for all the possible cases obtained from the developed model we show how this new model generalizes several inventory models proposed in the literature finally numerical results are presented to analyze the sensitivity of the optimal policies with respect to changes in some parameters of the system

criteria for evaluating purchase quantity decisions in response to future price increases abstract previous research for determining ordering strategies in response to known future price increases has not incorporated the actual cost functions it is shown that when these functions are utilized the optimal strategy depends on the time horizon studied an alternative criterion is offered which incorporates the actual cost comparisons and which provides recommendations consistent with previous research the formulation given provides a general framework for studying ordering strategies based on price changes

dynamic pricing of inventory capacity with infrequent price changes we consider a problem of dynamically pricing a single product sold by a monopolist over a short time period if demand characteristics change throughout the period it becomes attractive for the company to adjust price continuously to respond to such changes i e price discriminate intertemporally however in practice there is typically a limit on the number of times the price can be adjusted due to the high costs associated with frequent price changes if that is the case instead of a continuous pricing rule the company might want to establish a piece wise constant pricing policy in order to limit the number of price adjustments such a pricing policy which involves optimal choice of prices and timing of price changes is the focus of this paper we analyze the pricing problem with a limited number of price changes in a dynamic deterministic environment in which demand depends on the current price and time and there is a capacity inventory constraint that may be set optimally ahead of the selling season the arrival rate can evolve in time arbitrarily allowing us to model situations in which prices decrease increase or neither we consider several plausible scenarios where pricing and or timing of price changes are endogenized various notions of complementarity single crossing property supermodularity and total positivity are explored to derive structural results conditions sufficient for the uniqueness of the solution and the monotonicity of prices throughout the sales period furthermore we characterize the impact of the capacity constraint on the optimal prices and the timing of price changes and provide several other comparative statics results additional insights are obtained directly from the solutions of various special cases

optimizing inventory s contribution to profitability in a regulated utility the averch johnson effect the averch johnson effect is a well known economic phenomenon through which regulated utility companies prefer a capital resource input combination that differs from an efficient level through dynamic network data envelopment analysis ndea this paper first investigates the existence of this effect on a dynamic input that is inventory the analysis was performed for a group of public electric utilities from 2005 to 2014 the result implies that these firms procure a significant extra amount in inventory materials and supplies beyond their efficient levels in order to explore the connection of this effect to profit motives we construct an analytical model of the inventory policy controlling the extra buying of material and supplies that will be inventoried and added to the firm s rate base the model is based on maximizing the net present value of total profits in the deterministic case two results are observed i the firm could achieve a finite optimum by adding a finite amount of inventory above the normal base level which assumes no impact of inventory on the rate hearing and ii the firm could theoretically achieve infinite optimum under the unconstrained model the primary contribution of this paper is the special case of extending typical inventory replenishment models to including the impact on prices and in turn profits in a regulated supply chain

competition under capacitated dynamic lot sizing with capacity acquisition lot sizing and capacity planning are important supply chain decisions and competition and cooperation affect the performance of these decisions in this paper we look into the dynamic lot sizing and resource competition problem of an industry consisting of multiple firms a capacity competition model combining the complexity of time varying demand with cost functions and economies os scale arising from dynamic lot sizing costs is developed each firm can replenish inventory at the beginning of each period in a finite planning horizon fixed as well as variable production costs incur for each production setup along with inventory carrying costs the individual production lots of each firm are limited by a constant capacity restriction which is purchased up front for the planning horizon the capacity can be purchased from a spot market and the capacity acquisition cost fluctuates with the total capacity demand of all the competing firms we solve the competition model and establish the existence of a capacity equilibrium over the firms and the associated optimal dynamic lot sizing plan for each firm under mild conditions

empowering change the effects of energy provision on individual aspirations in slum communities this paper discusses the role of energy provision in influencing the social aspirations of people living in slums we examine factors that influence the shift in aspirations in five slum settlements using data from 500 interviews conducted in serviced and non serviced slums from the state of gujarat in india the non serviced slums did not have access to basic services namely water sanitation energy roads solid waste and rainwater management we find empirical evidence which suggests that when basic infrastructure provisions are met slum dwellers shift their focus from lower order aspirations to the higher order aspirations like health education housing and land ownership we argue that energy provision enhances productivity and enables slum dwellers to shift their aspirations upwards furthermore we test the effect of work days lost due to illness on the relationship between higher order aspirations and aspirations for energy provision when provision of energy is low higher work day loss dampens higher order aspirations for policy makers this study highlights the critical link between the infrastructure services preferred by slum dwellers and their social aspirations for growth

dynamic lotsizing with a finite production rate the dynamic lotsizing problem concerns the determination of optimally produced delivered batch quantities when demand which is to be satisfied is distributed over time in different amounts at di

replenishment and stocking policies for inventory systems with random deal offerings this paper considers the replenishment and stocking decision for inventory systems in which price discounts referred to as deals are offered by the supplier or the market place at random points in time assuming that the demand is constant over time the times between deal offerings are exponentially distributed and that the order leadtimes are negligible we derive expressions for evaluating the operating characteristics of the model moreover we derive expressions for determining the optimal policy parameters for such systems and present results on the behavior of the optimal policy parameters our results are easy to implement intuitive and provide managerial insights and a better understanding on the effect of random deal offerings on replenishment and stocking decisions in addition we suggest a back of envelope heuristic solution for deriving the policy parameters

optimal price markup policy for an inventory model with random price fluctuations and option for additional purchase abstract in this paper based on the analysis of empirical data of dealer and retailer prices and sales of cement as a prototype of functional products we develop a probabilistic inventory model for the situation when dealer s selling price fluctuates and affects the retailer s selling price demand is a function of price markup and retailer s purchase price dynamic price markup policy is proposed and optimal length of replenishment cycle and order quantity is obtained concavity of the profit function with respect to price markup is discussed a procurement policy which considers opportunity of purchase at a low price before the end of the optimal replenishment cycle is proposed and compared with other policies algorithm numerical examples sensitivity analysis and managerial insights are presented

a co ordination model combining incentive scheme and co ordination policy for a single vendor multi buyer supply chain abstract incentive scheme and co ordination policy are substantial components for the co ordination of a decentralized supply chain system but there is little work combining the two components as a single decision model li and wang 2007 this paper proposes a model which incorporates both incentive and co ordination issues into a single co ordination model for a single vendor multi buyer supply chain in the proposed model the co ordination is achieved by synchronizing ordering and production cycles while price discount which is based on the buyers order intervals is used as the incentive to motivate buyers to participate in the co ordination while the vendor is benefited from the co ordination by synchronized cycles the proposed price discount scheme can guarantee that a buyer s total relevant cost of co ordination will be reduced when compared with independent optimization more importantly the proposed price discount scheme does not require any cost information from the buyers

marginal welfare measures for discrete choice models abstract this letter deals with the use of discrete choice models for applied welfare analysis an approximate formula is presented for the marginal willingness to pay for a change in the attributes of any of the discrete alternatives which is simple to calculate and has an intuitive interpretation

linkages between industrialization strategies and industrial relations human resource policies singapore malaysia the philippines and india the case studies of singapore malaysia the philippines and india presented in this paper support the author s contention that a country s industrialization strategy for economic development profoundly influences its industrial relations ir and human resources hr policy goals the author finds that import substitution industrialization was associated with ir hr policy goals of pluralism and stability while a low cost export oriented industrialization strategy was associated with ir hr policy goals of cost containment and union suppression in countries that moved from a low cost export oriented strategy to a higher value added export oriented strategy the focus of ir hr policy goals shifted from cost containment to work force flexibility and skills development the four countries diverged however in the specific institutions and arrangements they adopted to meet national ir hr policy goals due to different political choices made by dominant actors and different institutional industrial relations histories

optimal ordering policies in response to a discount offer abstract sometimes supplier offers a temporary price discount to increase cash flow or decrease the inventory level of certain items thus the manufacturer may be able to improve the effectiveness of his inventory system by ordering a special quantity at this sale period in this paper economic order quantity eoq models with a discounted price are developed to obtain the optimal ordering policy during the sale period for five different cases a coincidence of sale period with replenishment time b non coincidence of sale period with replenishment time c sale period is longer than a cycle d discounted price as a function of the special ordering quantity and e incremental discount each case has its own characteristics of the sale period and the discounted price the objective is to take the maximum possible advantage from the discounted price by ordering a special quantity during the sale period the optimal ordering policy is obtained by maximizing the difference between the two costs regular eoq cost and special quantity cost during the sale period moreover a comparison of different discount scenarios is developed to sense the effect of different parameters on the ordering policies the annual gain obtained is linearly related to the discount and the on hand remnant inventory numerical analyses are provided to illustrate and testify the values of the optimal special quantity the analysis showed an impressive improvement in the effectiveness of the inventory system when a special order is placed during the sale period the optimal special quantity is driven for each case to visualize real life problems sensitivity analysis is also initiated to study the change in the total savings with respect to the variation of the special optimal quantity

a note on optimal ordering policies in response to a discount offer abstract in this short note we are suggesting a marginal analysis approach over the approach used by sarker and al kindi 2006 optimal ordering policies in response to a discount offer international journal of production economics 100 2 195 211 for developing models for determining the optimal ordering policy for an item for which the supplies offer a price discount during a sale period

discount pricing decisions in distribution channels with price sensitive demand abstract in this paper we evaluate the effectiveness of quantity discounts and volume discounts as coordination mechanisms in distribution channels with demand that is price sensitive we consider a single vendor single retailer distribution channel demand for the product arises only at the retailer the demand faced by the retailer is assumed to be deterministic but price elastic the retailer in turn buys the product from the vendor the vendor and the retailer act independently and rationally each maximizing their own respective profit the equilibrium point that specifies the vendor s and buyer s inventory and pricing policy is determined by the solution to a stackelberg game we consider the cases when quantity discount and volume discount respectively are offered we develop methods to determine the optimal discount policy for these cases we then consider the case where both volume and quantity discounts are offered simultaneously and develop a method to determine the optimal simultaneous discount offer the relative performance of the alternative discount schemes is then evaluated through a numerical study the results of the study demonstrate that the effectiveness of volume discount as a coordination mechanism is higher when the sensitivity of demand to price changes is higher the effectiveness of quantity discount on the other hand is higher with lower price sensitivity of demand finally the results also demonstrate that perfect coordination is achieved when volume and quantity discounts are offered simultaneously

raw material procurement with fluctuating prices abstract increasing global competition and cost pressure force enterprises and supply chains to discover undetected cost saving potentials in particular interfaces to the raw materials market are a promising field for improvement this paper presents a deterministic optimal control approach optimizing the procurement and inventory policy of an enterprise that is processing a raw material when the purchasing price holding cost and the demand rate fluctuate over time applying pontryagin s maximum principle the optimal policy turns out to be of a bang bang type involving impulse and just in time procurement numerical examples illustrate the solutions obtained and compare the optimal policy with simple replenishment strategies

advance booking discount programs under retail competition we model a situation in which two retailers consider launching an advance booking discount abd program in this program customers are enticed to precommit their orders at a discount price prior to the regular selling season however these precommitted orders are filled during the selling season while the abd program enables the retailers to lock in a portion of the customer demand and use this demand information to develop more accurate forecasts and supply plans the abd price reduces profit margin we analyze the four possible scenarios wherein each of the two firms offer an abd program or not and establish conditions under which the unique equilibrium calls for launching the abd program at both retailers

models of joint economic lot sizing problem with time based temporary price discounts abstract in this research we develop mathematical models of joint economic lot sizing problem jelp in a situation when a supplier offers time based temporary price discounts to a buyer during a sale period to respond this the buyer places a special order with higher quantity in literature it has been assumed that the buyer tends to place the special order at the end of the sale period we relax this assumption by considering the time when the buyer places the special order during the sale period i e the sooner the special order took place the higher discount received in our proposed models called joint economic lot sizing problem with time based temporary price discounts jelptpd we devide the sale period into k phases the buyer must place the special order in one of these phases the highest discount will be given when the special order is placed at the first phase while the lowest one will be given when it is placed at the k th phase there are two cases discussed the first case is when the sale period is uniformly divided while the second case is when the sale period is proportionally divided following some rules our numerical experiments showed the behavior of the buyer to respond the temporary price discount offers in major experiments the buyer shifted the decision on placing the special order in the earlier phases instead of the end of the sale period

trade openness and wage inequality evidence for malaysia this article examines the impact of trade openness on wage inequality in malaysia during the period 1984 1997 malaysia has operated a very open trade regime since the 1960s and has pursued aggressive import substitution and export supporting policies this development strategy is very different to that adopted in many other emerging economies where trade liberalisation has been associated with greater wage inequality the aim of the present study is to examine whether malaysia s more open approach to international trade has had a similar effect on wage inequality the results suggest in fact that this is not the case

measuring the welfare effects of slum improvement programs the case of mumbai this paper evaluates the welfare effects of in situ slum upgrading and relocation programs using data for 5000 households in mumbai india we estimate a model of residential location choice in which households value the ethnic composition of neighborhoods and employment accessibility in addition to housing characteristics the importance of neighborhood composition and employment access implies that relocation programs must be designed carefully if they are to be welfare enhancing the value of our model is that it allows us to determine the magnitude of these effects it also allows us to determine the value households place on in situ improvements which policymakers need to know if they are to design housing programs that permit cost recovery

optimal ordering strategies for announced price increases the familiar model for determining the optimal ordering strategy given an announced price increase assumes that the buyer has an opportunity to place an order at the end of the next economic order quantity cycle before the price increase takes effect this paper extends the price increase model by relaxing the requirement on the timing of the price increase specifically we develop optimal ordering strategies for situations where the price increase becomes effective at any future specified time we also calculate savings for alternate ordering strategies

an inventory control model with stochastic review interval and special sale offer abstract periodic review inventory models are widely used in practice especially for inventory systems in which many different items are purchased from the same supplier however most of periodic review models have assumed a fixed length of the review periods in practice it is possible that the review periods are of a random stochastic length this paper presents an inventory control model in the case of random review intervals and special sale offer from the supplier the replenishment interval is assumed to obey from two different distributions namely exponential and uniform distributions also shortages are allowed in the term of partial backordering for this model its convexity condition is discussed and closed form solutions are proposed

note on an eoq model with a temporary sale price a flaw is revealed in the formulation of a fundamental temporary sale price model however its impact is only relatively significant when the amount of the discount is small

capital accumulation trade liberalization and rising wage inequality the case of argentina abstract capital accumulation can modify the relative productivity between skilled and unskilled workers leading to changes in the wage structure in particular if capital goods are relatively more complementary to skilled workers a positive correlation between investment in physical capital and the wage premium would be expected in this article we present evidence for this hypothesis by taking advantage of the variability in wage premia and capital investment across industries in argentina s manufacturing sector we conclude that the wage premium for skilled workers increased more in those industries with higher investment in machinery and equipment the overall evidence seems to indicate that industry affiliation is an important determinant of earnings differentials by skill group

implications of alternate policies on welfare of slum dwellers evidence from pune india abstract in this paper we examine how slum dwellers value location based amenities in most developing country cities residents living in slums have poor quality dwellings and limited access to basic public services and amenities using data from pune india we estimate the residential location choices of slum dwellers which are conditional on housing quality neighborhood amenities and community structure we use these estimates to simulate the impact of alternate interventions on household welfare we find that households derive benefits from housing quality and neighborhood amenities while relocating households to the periphery has adverse consequences for household welfare we show that households could be adequately compensated out of the increased tax revenue accruing from alternative uses of the vacated central land

trade technology and uk wage inequality this paper examines the impact of international trade and technical change on changes in the uk skill premium we first measure trade as changes in product prices and technical change as tfp growth then we relate price and tfp changes to a set of underlying forces among our results are a changes in prices not tfp were the major force behind the rise in inequality in the 1980s b changes in oecd prices and uk tariffs significantly raised 1980s skill premia through their effects on prices and that industry concentration significantly raised 1980s skill premia through its effect on tfp

evaluation of capital costs in a multi level inventory system by means of the annuity stream principle abstract in this paper some results obtained from applying the annuity stream principle for evaluating capital tied up in inventory and work in progress and presented this principle departs from the cashflows associated with the production inventory processes considered in contrast to traditional procedures by which the inventory value is determined from physical stock evaluated at costs incurred to date in many situations it appears that the traditional procedure will underestimate the amount of capital tied up in production in this paper the two principles are applied to a multi level inventory system and the capital cost expressions and optimal order quantities are compared

infrastructure provision gender and poverty in indian slums we examine the relationship between infrastructure provision and poverty alleviation by analyzing 500 interviews conducted in serviced and non serviced slums in india using a mixed method approach of qualitative analysis and regression modeling we find that infrastructure was associated with a 66 increase in education among females service provision increased literacy by 62 enhanced income by 36 and reduced health costs by 26 evidence suggests that a gender sensitive consideration of infrastructure is necessary and that a one size fits all approach will not suffice we provide evidence that infrastructure investment is critical for well being of slum dwellers and women in particular

evaluating lot sizing strategies under limited time price incentives an efficient lower bound abstract determination of the optimal lot sizing strategy when the vendor offers limited time price incentives such as pre announcement of a price increase that will take effect after a finite time or a price discount that is valid for a limited time is a common problem that has been extensively researched a review of the literature indicates that the mathematical analysis and solution of this problem are quite complex this complexity may deter managers from using the optimal strategy although an optimal lot sizing strategy results in the lowest cost managers generally prefer simple heuristic or rule of thumb strategies that are easy to understand and to implement provided the total relevant cost associated with such strategies compares well with that of the optimal strategy therefore it would be of significant value to managers if the cost associated with the optimal strategy can be deduced easily without recourse to complex mathematical analysis so that the simpler strategies can be quickly and easily evaluated in this paper we present an intuitively appealing and easy to compute method to determine a tight lower bound whose value is very close to the total cost of the optimal strategy we demonstrate through extensive computational analysis the adequacy of our lower bound by comparing it with the total cost associated with an optimal strategy over a wide range of operating parameters thus managers can use it as a surrogate for the cost of the optimal strategy while evaluating heuristic strategies we illustrate the application of our lower bound with numerical examples

procurement planning to maintain both short term adaptiveness and long term perspective we study the fuel procurement problem for electrical utilities under uncertain demand and market price long term contractual supply commitments are made at a set price with fuel suppliers at the beginning of each year each month the procurement planner can use fuel from these contracts or purchase fuel at the current market price motivated by practical insights from this market we propose a two phase dynamic procedure to determine a procurement plan in the first phase the minimum contract purchases for each month are determined at the beginning of the year in the second phase given the minimum contract purchases the more detailed procurement decisions are determined at the beginning of each month with the most up to date information we perform intensive computational experiments that show that this procedure produces high quality solutions comparable to a rolling horizon stochastic programming heuristic is easier to maintain and generalize is computationally faster and is robust to random fluctuations in demand requirements spot market prices and other sources of uncertainty

optimal order quantity and pricing decisions in single period inventory systems abstract in this paper we consider simultaneous pricing and procurement decisions associated with a one period pure inventory model under deterministic or probabilistic demand we investigate the necessary and sufficient conditions for an type policy to be optimal for the determination of the procurement quantity we also show how the corresponding optimal price can be obtained

one time only incentives and inventory policies abstract this paper presents a review of the literature available on inventory policies under incentives on a one time only basis it is quite a common industrial practice to offer special incentives to motivate the buyer to order in larger than regular order quantities such special deals are available for a limited time only the literature on inventory policies under conditions of incentives has been classified by the nature of incentives such as price discount and credit period a situation of announced price increase which is very similar to price discount is also reviewed the policy implications of various scenarios are highlighted and areas of future research are identified

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

dual sourcing using capacity reservation and spot market optimal procurement policy and heuristic parameter determination abstract this contribution focuses on the cost effective management of the combined use of two procurement options the short term option is given by a spot market with random price whereas the long term alternative is characterized by a multi period capacity reservation contract with fixed purchase price and reservation level a reservation cost proportional with the reservation level has to be paid for the option of receiving any amount per period up to the reservation level a long term decision has to be made regarding the reserved capacity level and then it has to be decided period by period which quantities to procure from the two sources considering the multi period problem with stochastic demand and spot price the structure of the optimal combined purchasing policy is derived using stochastic dynamic programming exploiting these structural properties an advanced heuristic is developed to determine the respective policy parameters this heuristic is compared with two rolling horizon approaches which use the one period and two period optimal solution a comprehensive numerical study reveals that the approaches based on one period and two period solutions have considerable drawbacks while the advanced heuristic performs very well compared to the optimal solution finally by exploiting our numerical results we give some insights into the system s behavior under problem parameter variations

there is no free house abstract this paper estimates the effect of a housing relocation program on the labor supply and living conditions of low income households across major cities in south africa using panel microdata collected between 2008 and 2014 it exploits the arbitrary eligibility rules of the policy with a fuzzy regression discontinuity design to obtain reduced form estimates there are three main findings first in the short term of 2 to 4 years following relocation the labor supply of recipient households decreases driven mostly by a reduction of female hours second the large increase in distance km to economic opportunities seems to be an important factor behind the decline directly or indirectly through family shifts in earning strategies finally evidence is limited regarding improvements in housing and neighborhood quality overall there is no clear indication that the net welfare effect of relocation is positive

an eoq model for perishable product with special sale and shortage abstract in this paper for the first time an inventory control model to determine the optimal order and shortage quantities of a perishable item when the supplier offers a special sale is developed four possible cases based on decision that the purchaser might make about the first replenishment policy using regular economic order quantity model at reduced price or regular price if he did not take the special order and coincidence of special period length with positive or negative inventory level of the last regular period length during the special period are investigated moreover several useful theorems are suggested through which one can find closed form solution directly when there are integer operators involved in an objective function at the end in order to illustrate the proposed theorems and the solution method some numerical examples are solved and a sensitivity analysis is reported too

skill biased technology transfer around the world in this paper we consider the extent to which skill biased technological changes are transferring across international borders thereby altering the skill structure of labour markets evidence of increased relative demand for skilled workers is uncovered in the manufacturing sectors of 37 high middle and low income countries skill biased technology transfer is central to the increased demand for skilled workers in middle income countries in low income countries there is less evidence of such a mechanism operating

ordering and inventory policies for step changes in the unit item cost a discounted cash flow approach this paper considers the problem of determining the optimal ordering quantities of a purchased item where there are step changes in price either up or down other costs incurred include ordering costs associated with each replenishment and holding costs related to capital tied up in inventory and physical stock holding the net present value npv principle is applied explicit expressions for the development of the optimal order quantities over time are presented it is shown that three cases may be distinguished i when the price change is very small ii when an essential price increase occurs and iii when there is an essential price decrease although the optimal last order quantity before a price increase is similar in magnitude to what has been presented in other articles applying average cost approaches in certain respects this paper offers novel results contradictory to those suggested by other authors analysis shows that the average cost model solutions are first order approximations in the discount rate numerical evaluations of a range of price increases and times to the price increase suggest that with certain important caveats the average cost formulae are likely to be acceptable for most practical situations for the infinite horizon situation

periodic pricing of seasonal products in retailing this paper studies intertemporal pricing policies when selling seasonal products in retail stores we first present a continuous time model where a seller faces a stochastic arrival of customers with different valuations of the product for this model we characterize the optimal pricing policies as functions of time and inventory we use this model as a benchmark against which we compare more realistic models that consider periodic pricing reviews we show that the structure of the optimal pricing policies in this case is consistent with the procedures observed in practice retail stores successively discount the product during the season and promote a liquidation sale at the end of the planning horizon we also show that the loss experienced when implementing periodic pricing reviews instead of continuous policies is small when the appropriate number of reviews is chosen several interesting economic insights emerge from our analysis for example uncertainty in the demand for new products leads to higher prices larger discounts and more unsold inventory finally we study the effect of announced discount policies on prices and profits we show that stores that have adopted this type of strategy usually set prices such that with high probability the merchandise is sold during the first periods and the largest discounts rarely take place

an optimal control of inventory under probablistic replenishment intervals and known price increase abstract the unit purchase price of products may increase or decrease for various reasons which influences the seller s and buyer s inventory control policies this paper develops an inventory control model when replenishment intervals are probabilistic and partial backordering in which an announced price increase happens and the buyer can make a special order before the price increase initiates inventory at the beginning of the period is not equal to zero and can be positive or negative amounts the main aim of this paper is to determine the optimum amount of replenish up to level in special sale offer this model is analyzed in two cases according to the inventory level in which the price increase happens and both cases are formulated to maximize the total saving function for placing a special order or not a closed form solution is obtained for the optimum amount of a special order two special cases with the replenishment intervals following uniform or exponential distributions are studied with sensitivity analysis the results indicate that a buyer can determine the optimal values of the maximum level of inventory and order quantity when the time between two consecutive replenishments is a probabilistic variable and the buyer experiences known price increase for which the total profit is maximized

effects of a demand curve s shape on the optimal solutions of a multi echelon inventory pricing model abstract when a price demand relationship is needed in inventory pricing models very often a convenient typically linear function is arbitrarily chosen the common wisdom implication is that any downward sloping demand curve would lead to similar conclusions this paper applies different demand curve functions to a simple inventory pricing model and shows that while the common wisdom implication is valid for a single echelon system assuming different demand curve functions can lead to very different results in a multi echelon system in some situations a very small change in the demand curve appearance leads to very large changes in the model s optimal solutions other significant but counter intuitive effects of the demand curve form are also revealed this paper does not completely resolve the difficulties revealed by the counter intuitive effects reported here but establishing the existence of these effects represents a first step towards developing procedures to handle such effects these procedures will be necessary to ensure the reliability of many multi echelon models for products having price sensitive demands

resilient supply chain network design under competition a case study abstract this research motivated by a real life case study in a highly competitive automobile supply chain experimentally studies the impact of disruption on the competitiveness of supply chains the studied supply chain faces two major risks disruption of suppliers and tough competition from competitors any disruption in upstream level of the supply chain leads to an inability to meet demand downstream and causes market share to be lost to the competitors for such a setting a resilient topology is redesigned that can recover from and react quickly to any disruptive incidents to this aim we speculate there are three policies that can be used to mitigate the disruption risk namely keeping emergency stock at the retailers reserving back up capacity at the suppliers and multiple sourcing the problem is addressed using a mixed integer non linear model to find the most profitable network and mitigation policies we design a piecewise linear method to solve the model based on the data extracted from an automotive supply chain practical insights of the research are extracted in a controlled experiment our analysis suggests that implementing risk mitigation policies not only work to the advantage of the supply chain by sustaining and improving its market share but also benefit customers by stabilizing retail prices in the market using the case study we analyze the contribution of each risk strategy in stabilizing the supply chain s profit market share and retail price our analysis reveals that downstream emergency stock is the most preferable risk mitigation strategy if suppliers are unreliable

retail price markup commitment in decentralized supply chains abstract we investigate the operational decisions and resulting profits for a supply chain facing price dependent demand under a policy where there is an ex ante commitment made on the retail price markup we obtain closed form solutions for this policy under the assumption of a multiplicative demand function and we analytically compare its performance with that of a traditional price only policy we compare these results to results obtained when demand follows a linear additive form these formulations are shown to be qualitatively different as the manufacturer s wholesale pricing decision is independent of the retail price markup commitment in the multiplicative case but not when demand is linear additive we demonstrate that the ex ante commitment can lead to pareto improving solutions under linear additive demand but not under the multiplicative demand function we also consider the effect of pricing power in the supply chain by varying who determines the retail price markup

holding costs under push or pull conditions the impact of the anchor point holding costs are traditionally determined from the investment in physical stock during a cycle an alternative approach instead derives holding costs from net present value npv functions it is known that applying both frameworks to the same system can lead to different holding cost valuations but little explanation has been offered by introducing the anchor point in a model this paper shows for four different systems that traditional holding cost models implicitly assume pull conditions while current npv approaches model push conditions this explains in part the differences between the methods it is shown that the anchor point concept allows the construction of npv models under pull conditions giving results in better correspondence with traditional models the traditional framework is restricted to pull conditions and important considerations could be easily overlooked leading to wrong valuations of holding costs npv seems superior as such considerations are automatically incorporated the application to multi echelon inventory systems provides interesting insights on the roles of echelon stocks and lead times and offers potential for future research

optimal ordering policies in response to a discount offer corrections abstract recently sarker and kindi 2006a optimal ordering policies in response to a discount offer international journal of production economics 100 2 195 211 presented an inventory model from the purchaser s perspective to determine the optimal ordering policies in response to a discount offer established by the supplier for five possible cases this study presents some practical extensions to the optimal ordering policies developed by sarker and kindi 2006a optimal ordering policies in response to a discount offer international journal of production economics 100 2 195 211

market government and malaysia s new economic policy leading economic institutions such as the world bank have argued that liberalisation holds the key to growth poverty alleviation and redistribution even recent efforts to model increasing returns within the framework of new growth theories have not resulted in prescriptions for stronger roles for governments the fast growing southeast asian economies are still being used to demonstrate causation between liberalisation and growth poverty alleviation and redistribution using malaysia as an example this paper argues that growth poverty alleviation and redistribution in the country was achieved under circumstances of both interventionist policies as well as market coordination throughout the new economic policy nep period 1970 90 strong incentives were offered to both the import substitution and exportoriented manufacturing sectors and the state made strong forays into the market to redress poverty and inequality the paper also argues that poorly coordinated government intervention generated substantial unproductive rent seeking

orders and inventory commodities with price and demand uncertainty in complete markets abstract the purpose of this paper is to price an order inventory control policy when both the demand and the price are uncertain and markets are complete inventory management is assumed to be equivalent to an investment for future and risky prospects for which a risk premium is required optimization of this risk premium defines the optimal order policy a number of examples are solved and we show how a zero inventory policy can be replicated by a portfolio of options and of course an optimal order quantity the approach developed in this paper underlies as well a common practice by certain firms who use materials that are traded in speculative financial markets in these situations managers combine their production based activities with speculations regarding their potential demand and the associated price of materials for demonstration purposes and to highlight the practicality of this approach an extensive application and numerical results are used in particular we consider a two period problem with an exponential utility function and a mean exponential demand which is a function of price

optimal inventory policy for a perishable item with demand function sensitive to price and time abstract we formulate a model for determining the optimal pricing order quantity and replenishment period for perishable items with price dependent and time dependent demand the items have a fixed shelf life and the demand rate decreases linearly in the selling price and polynomially over the time after replenishment until it vanishes either at the reservation price or at expiration time we prove that the three variable profit maximization problem can be reduced into a single variable problem in which the variable is the duration of the replenishment period we show that the profit function is strictly pseudo concave and provide means of obtaining the optimal policy three numerical examples are presented to demonstrate the model accompanied by a sensitivity analysis

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

dynamic pricing in the presence of inventory considerations research overview current practices and future directions the benefits of dynamic pricing methods have long been known in industries such as airlines hotels and electric utilities where the capacity is fixed in the short term and perishable in recent years there has been an increasing adoption of dynamic pricing policies in retail and other industries where the sellers have the ability to store inventory three factors contributed to this phenomenon 1 the increased availability of demand data 2 the ease of changing prices due to new technologies and 3 the availability of decision support tools for analyzing demand data and for dynamic pricing this paper constitutes a review of the literature and current practices in dynamic pricing given its applicability in most markets and its increasing adoption in practice our focus is on dynamic intertemporal pricing in the presence of inventory considerations

a deteriorating inventory model with a temporary price discount abstract inventory models considering a temporary price discount have recently become an active area of research in this study an extension is made to consider the fact that some commodities may deteriorate during storage the models also incorporate three additional assumptions that have been neglected by researchers two models for the exponentially deteriorating items with a temporary price discount are developed for a regular and non regular inventory replenishment time our goal in this research is to maximize the total cost saving during the temporary price discount order cycle a numerical example is provided to illustrate the theory

closed form solutions for wee s and martin s eoq models with a temporary price discount abstract in this article we use closed form solutions to solve wee and yu 1997 deteriorating inventory model with a temporary price discount and martin s 1994 eoq model with a temporary sale price in wee and yu 1997 and martin s 1994 the benefits during the temporary price discount purchase cycle are represented by their objective functions wee and yu 1997 and martin 1994 only used search methods to find approximate solutions following the theorems we suggested you can find closed form solution directly when there are integer operators involve in an objective function using the data of wee and yu 1997 and martin 1994 we can find the results are more quick and more accurate

an economic order quantity model with partial backordering and a special sale price abstract a constant unit purchase cost is one of the main assumptions in the classic economic order quantity model in practice suppliers sometimes offer special sale prices to stimulate sales or decrease inventories of certain items in this paper we develop an eoq model with a special sale price and partial backordering we prove the convexity of the cost reduction function if a special order is placed at the special sale price a solution method is proposed and numerical examples are presented

tenure security and urban squatting while recent studies have shown that up to 35 of the total urban population of the third world live in squatter settlements there is a dearth of economic analysis on the phenomenon of squatting this paper attempts to fill this gap the equilibrium model argues that the difference in unit housing prices between the non squatting formal sector of a city and its squatting informal sector reflects the premium associated with a secure tenure status the empirical portion of this paper uses hedonic price techniques to derive the average premium on tenure security in a medium sized philippine city davao results show that formal sector unit dwelling prices are about 18 renters to 58 owners more than in the informal sector these equilibrium price differentials were found to be greater for lower income groups larger household sizes and households with older heads for renters and younger heads for

estimating stated preferences with rated pair data environmental health and employment effects of energy programs abstract respondents stated preferences for attributes related to various electricity generation scenarios are analyzed using a series of pairwise ratings multiple observations for each respondent facilitate estimating individual scale parameters scale estimates can identify uninformative rating patterns and make it possible to delete such observations or adjust wtp calculations cross section time series analysis of the data indicates that nonprice attributes increase in salience during the course of the experiment thus later responses may be better indicators of preferences than earlier responses comparisons of polychotomous with dichotomous models indicate that most respondents relative preference ratings are not simply dichotomous but discriminate systematically along the rating scale