price dumping in intermediate good markets abstract we analyze price dumping and anti dumping duties in the context of a model with a vertical industry structure dumping in the intermediate good market arises from differences in country specific final good production costs the price differential or dumping margin is shown to increase as the productivity difference increases an anti dumping duty designed to reduce the equilibrium price differential has two effects on welfare a welfare loss from reduced final good production and a contrasting gain achieved by producing the lower output level more efficiently

competition and unilateral dumping this paper presents an analysis of the effects of market structure on the propensity of firms to dump goods the analysis of brander and krugman is extended to show that in the presence of transportation costs bilateral intra industry trade is not possible without dumping contrary to the conventional wisdom this paper finds that firms in markets with a large number of domestic competitors are more prone to dump unilaterally than firms in less competitive markets this dumping is not predatory but may result in export prices being below average cost

computing the non stationary replenishment cycle inventory policy under stochastic supplier lead times in this paper we address the general multi period production inventory problem with non stationary stochastic demand and supplier lead time under service level constraints a replenishment cycle policy r n s n is modeled where r n is the n th replenishment cycle length and s n is the respective order up to level we propose a stochastic constraint programming approach for computing the optimal policy parameters in order to do so a dedicated global chance constraint and the respective filtering algorithm that enforce the required service level are presented our numerical examples show that a stochastic supplier lead time significantly affects the structure of the optimal policy with respect to the case in which the lead time is assumed to be deterministic or absent

an milp approximation for ordering perishable products with non stationary demand and service level constraints abstract we study the practical production planning problem of a food producer facing a non stationary erratic demand for a perishable product with a fixed life time in meeting the uncertain demand the food producer uses a fifo issuing policy the food producer aims at meeting a certain service level at lowest cost every production run a setup cost is incurred moreover the producer has to deal with unit production cost unit holding cost and unit cost of waste the production plan for a finite time horizon specifies in which periods to produce and how much we formulate this single item single echelon production planning problem as a stochastic programming model with a chance constraint we show that an approximate solution can be provided by an milp model the generated plan simultaneously specifies the periods to produce and the corresponding order up to levels the order up to level for each period is corrected for the expected waste by explicitly considering for every period the expected age distribution of the products in stock the model assumes zero lead time and backlogging of shortages the viability of the approach is illustrated by numerical experiments simulation shows that in 96 4 of the periods the service level requirements are met with an error tolerance of 1

a simple approach for assessing the cost of system nervousness abstract a well known problem in coordinating supply chain inventories is that replenishment decisions are revised due to stochastic demands this issue is often referred to as system nervousness the literature distinguishes between two types of nervousness setup oriented and quantity oriented it is widely accepted that cost of nervousness is difficult to measure we argue that this cost can be evaluated by means of three well established inventory control strategies static uncertainty dynamic uncertainty and static dynamic uncertainty these strategies reflect extreme cases with regard to the setup and the quantity oriented nervousness and provide a simple yet an objective measure to assess the cost of system nervousness our results are of practical importance we highlight that the setup oriented nervousness which is considered to be the most critical in practice can be eliminated with a minor cost penalty this is however not the case for the quantity oriented nervousness

dynamic uncapacitated lot sizing with random demand under a fillrate constraint abstract this paper deals with the single item dynamic uncapacitated lot sizing problem with random demand we propose a model based on the static uncertainty strategy of bookbinder and tan 1988 in contrast to these authors we use exact expressions for the inventory costs and we apply a fillrate constraint we present an exact solution method and modify several well known dynamic lot sizing heuristics such that they can be applied for the case of dynamic stochastic demands a numerical experiment shows that there are significant differences in the performance of the heuristics whereat the ranking of the heuristics is different from that reported for the case of deterministic demand

augmenting the lot sizing order quantity when demand is probabilistic abstract in this paper we consider a single item discrete time lot sizing situation where demand is random and its parameters e g mean and standard deviation can change with time for the appealing criterion of minimizing expected total relevant costs per unit time until the moment of the next replenishment we develop two heuristic ways of selecting an appropriate augmentation quantity beyond the expected total demand through to the planned deterministic time of the next replenishment the results of a set of numerical experiments show that augmentation is important particularly when orders occur frequently i e the fixed cost of a replenishment is low relative to the costs of carrying one period of demand in stock and the coefficient of variability of demand is relatively low but also under other specified circumstances the heuristic procedures are also shown to perform very favourably against a hindsight baseline s s policy especially for larger levels of non stationarity

non stationary stochastic inventory lot sizing with emission and service level constraints in a carbon cap and trade system firms worldwide are taking major initiatives to reduce the carbon footprint of their supply chains in response to the growing governmental and consumer pressures in real life these supply chains face stochastic and non stationary demand but most of the studies on inventory lot sizing problem with emission concerns consider deterministic demand in this paper we study the inventory lot sizing problem under non stationary stochastic demand condition with emission and cycle service level constraints considering carbon cap and trade regulatory mechanism using a mixed integer linear programming model this paper aims to investigate the effects of emission parameters product and system related features on the supply chain performance through extensive computational experiments to cover general type business settings and not a specific scenario results show that cycle service level and demand coefficient of variation have significant impacts on total cost and emission irrespective of level of demand variability while the impact of product s demand pattern is significant only at lower level of demand variability finally results also show that increasing value of carbon price reduces total cost total emission and total inventory and the scope of emission reduction by increasing carbon price is greater at higher levels of cycle service level and demand coefficient of variation the analysis of results helps supply chain managers to take right decision in different demand and service level situations

intra industry trade in financial services abstract intra industry trade iit has been central to increasing the variety of products available to consumers unlike traditional trade theories the recent trade theories have placed an emphasis on the role of foreign direct investment fdi in generating trade and increasing the volume of iit this study is the first study of intra industry trade in banking services in which the key elements of the new trade theories of iit have been taken into account in measuring the determinants of iit in banking services the empirical results of the determinants of iit in banking services indicate that factor endowments average per capita income fdi in banking economies of scale in the banking sector trade intensity between the us and its partners and market openness make a positive contribution to the volume of iit in banking services furthermore the empirical results indicate that intra trade activities amongst the us multinational corporations reduce the level of iit in banking services for the us

economic impacts of the construction of a transport corridor a multi level and multi approach case study for the construction of the a1 highway in the netherlands bruinsma f r rienstra s a and rietveld p 1997 economic impacts of the construction of a transport corridor a multi level and multi approach case study for the construction of the a1 highway in the netherlands reg studies 31 391 402 in this paper the relation between the construction of highway infrastructure and regional economic development is analysed at two spatial levels the level of regions and individual entrepreneurs three different approaches are used a regional labour market model a reference region approach and a survey among entrepreneurs both the regional models gave no clear indication of an impact of highway construction on regional economic development at the level of individual entrepreneurs the impact of the highway construction was clearly positive for the level of corporate investments the number of employees the perceived accessibility travel time and the accuracy in delivery times perceptions deserve attention in studies of this type because behaviour is not on

the urban rural manufacturing shift in the european community the paper documents for the first time at the european community scale a relative shift of manufacturing industry from highly urbanised to rural regions during the 1970s this shift is evident in

multiple items procurement under stochastic nonstationary demands abstract in the consumer goods wholesaling and retailing industry a large number of stock keeping units must be managed on a regular basis the items are typically purchased in families each family being associated with a specific external vendor and usually there are some constraints on family order quantities and there are frequent opportunities to buy at a temporary low price the demand for an item is often stochastic and not stationary in this paper by computing procurement plans over rolling planning horizons we transform this difficult sequential decision problem into a multi period static decision problem under risk the problem is initially formulated as a stochastic program with simple recourse and a branch and bound algorithm is designed to solve an equivalent deterministic program a piecewise concave approximation is proposed to reduce this program to a linear program with one 0 1 variable per planning period the performances of the algorithms are studied in two simulation experiments the simulations show that when planning over a rolling horizon the approach proposed yields excellent results

order quantities for perishable inventory control with non stationary demand and a fill rate constraint abstract we study the practical decision problem of fresh food production with a long production lead time to decide every period e g week how many items to produce when a batch is ready for use its items have a fixed shelf life after which the items become waste in the sense that they cannot be sold anymore the demand for fresh food products is uncertain and highly fluctuating mainly caused by price promotions of retail organisations we focus on cases where a so called cycle fill rate service level requirement applies we investigate the generation of a production plan that fixes the timing and quantity of the production for a finite time horizon to minimise waste one issues the oldest items first i e a fifo issuing policy in case of out of stock sales are lost we model this decision problem as a stochastic programming sp model the objective of our study is to find order quantities for the sp model that approximately meet cycle fill rate service level requirements while keeping outdating low to find approximate solutions for the sp model an milp model is developed the milp model is a deterministic approximation that generates feasible replenishment quantities in less than a second with a scenario based minlp approach optimal solutions are generated for a large sample of demand paths as a benchmark for the milp solutions we show that the milp model is suitable for practical use if the setup cost is such that the replenishment cycles in the production plan are close to or of the same length as the maximum shelf life in those cases the expected total costs are close to the costs of the optimal solution and the average fill rate is close to the required one

market integration and competition in environmental and trade policies recent empirics suggest the relevance of transport cost reductions for world trade growth along with eliminations in protectionist trade barriers to address the welfare effects of trade cost reductions in a context of trade and the environment we develop a two stage game model where governments choose environmental and trade policies and firms play a cournot nash game we show that reductions in transport costs lead to lower emission taxes and higher tariffs and we find that the degree of pollution damage plays a central role in whether market integration is welfare improving relative to autarky

the stochastic dynamic production inventory lot sizing problem with service level constraints abstract this paper addresses the multi period single item inventory lot sizing problem with stochastic demands under the static dynamic uncertainty strategy of bookbinder and tan manage sci 34 1988 1096 in the static dynamic uncertainty strategy the replenishment periods are fixed at the beginning of the planning horizon but the actual orders are determined only at those replenishment periods and will depend upon the demand that is realised their solution heuristic was a two stage process of firstly fixing the replenishment periods and then secondly determining what adjustments should be made to the planned orders as demand was realised we present a mixed integer programming formulation that determines both in a single step giving the optimal solution for the static dynamic uncertainty strategy the total expected inventory holding ordering and direct item costs during the planning horizon are minimised under the constraint that the probability that the closing inventory in each time period will not be negative is set to at least a certain value this formulation includes the effect of a unit variable purchase production cost which was excluded by the two stage bookbinder tan heuristic an evaluation of the accuracy of the heuristic against the optimal solution for the case of a zero unit purchase production cost is made for a wide variety of demand patterns coefficients of demand variability and relative holding cost to ordering cost ratios the practical constraint of non negative orders and the existence of the unit variable cost mean that the replenishment cycles cannot be treated independently and so the problem cannot be solved as a stochastic form of the wagner whitin problem applying the shortest route algorithm

monopolistic competition and international trade reconsidering the evidence we test some propositions about international trade flows that are derived from models of monopolistic competition developed by elhanan helpman and paul krugman we investigate whether the volume of trade between oecd countries is consistent with the predictions of a model in which all trade is intraindustry trade in differentiated products we then repeat the test with non oecd countries we also investigate whether the share of intraindustry trade is consistent with a more general theoretical model in which some but not all trade is intraindustry trade our results lead us to question the apparent empirical success of these models

optimal dynamic procurement policies for a storable commodity with levy prices and convex holding costs abstract in this paper we study a continuous time stochastic inventory model for a commodity traded in the spot market and whose supply purchase is affected by price and demand uncertainty a firm aims at meeting a random demand of the commodity at a random time by maximizing total expected profits we model the firm s optimal procurement problem as a singular stochastic control problem in which controls are nondecreasing processes and represent the cumulative investment made by the firm in the spot market a so called stochastic monotone follower problem we assume a general exponential levy process for the commodity s spot price rather than the commonly used geometric brownian motion and general convex holding costs we obtain necessary and sufficient first order conditions for optimality and we provide the optimal procurement policy in terms of a base inventory process that is a minimal time dependent desirable inventory level that the firm s manager must reach at any time in particular in the case of linear holding costs and exponentially distributed demand we are also able to obtain the explicit analytic form of the optimal policy and a probabilistic representation of the optimal revenue the paper is completed by some computer drawings of the optimal inventory when spot prices are given by a geometric brownian motion and by an exponential jump diffusion process in the first case we also make a numerical comparison between the value function and the revenue associated to the classical static newsvendor strategy

intra industry trade and strategic interaction theory and evidence abstract we conduct a theory based empirical study of intraindustry trade in homogeneous products we derive an oligopolistic model of intra industry trade which is an extension of the segmented market model of trade initially proposed by brander j a 1981 intra industry trade in identical commodities journal of international economics 11 1 14 the empirical implementations of the model are investigated in the context of the petrochemical industry our analysis employs a unique data set containing detailed product and location specific data on the petrochemical industries in germany and the united states allowing for different empirical specifications we find that cross product variations in bilateral intra industry trade of petrochemicals are well explained by the variables suggested by the theoretical model

intra industry trade and industry distribution of productivity a cournot ricardo approach this paper constructs a cournot ricardo model of trade by incorporating cournot competition in a ricardian trade model in this model the share of intra industry trade in bilateral trade volume decreases as trading partners become more different in terms of the industry distribution of labor productivity we show that this relationship is a special case of a more general relationship the share of intraindustry is decreasing in a specialization index this specialization index turns out to be equal to the difference in the industry distribution of productivity in the case of our cournot ricardo model while it is given by the difference in capital labor in the well known case of monopolistic competition as both technologies and factor endowments would be important in shaping specialization patterns in the real world we conjecture that the share of intra industry trade is decreasing in two measures of specialization the difference in the industry distribution of productivity and the difference in capital ratio our ols estimations strongly support this conjecture in fixed effects regressions both measures lose significance in the entire sample but the industry distribution of productivity is significant in explaining trade between high income countries

is public expenditure productive abstract this paper considers the relationship between aggregate productivity and stock and flow government spending variables the empirical results indicate that i the nonmilitary public capital stock is dramatically more important in determining productivity than is either the flow of nonmilitary or military spending ii military capital bears little relation to productivity and iii a core infrastructure of streets highways airports mass transit sewers water systems etc has most explanatory power for productivity the paper also suggests an important role for the net public capital stock in the productivity slowdown of the last fifteen years

how bad is antidumping evidence from panel data abstract current research on antidumping suggests a number of channels through which antidumping affects the volume of world trade this paper uses a structural approach to the gravity model framework to evaluate these hypotheses using data on trade volume over the period 1948 to 2001 we conclude that the volume and welfare effects have been negative but quite modest

goods prices and exchange rates what have we learned import prices typically change by a smaller proportion than the exchange rate between the exporting and importing country recent research indicates that common currency relative prices for similar goods exported to different markets are highly correlated with exchange rates between those markets this evidence suggests that incomplete pass through is a consequence of third degree price discrimination while distance matters for market segmentation borders have independent effects the source of the border effect has not been clearly identified furthermore there is little evidence yet to suggest substantial market power is implied by the observed price discrimination

inventory models with minimal service level constraints abstract this paper investigates inventory models in which the stockout cost is replaced by a minimal service level constraint slc that requires a certain level of service to be met in every period the minimal service level approach has the virtue of simplifying the computation of an optimal ordering policy because the optimal reorder level is solely determined by the minimal slc and demand distributions it is found that above a certain critical service level the optimal s s policy collapses to a simple base stock or order up to level policy which is independent on the cost parameters this shows the minimal slc models to be qualitatively different from their shortage cost counterparts we also demonstrate that the imputed shortage cost transforming a minimal slc model to a shortage cost model does not generally exist the minimal slc approach is extended to models with negligible set up costs the optimality of myopic base stock policies is established under mild conditions

inventory policies for systems with stochastic and deterministic demand we consider a periodic review inventory system with demand arriving simultaneously from a deterministic source and a random source the deterministic demand has to be satisfied immediately and the stochastic demand can be backordered assuming that the stochastic demand is never backlogged if there is stock in the system we prove that a modified s s policy is optimal under general conditions if there is a setup cost if there is a smoothing cost instead of the setup cost we observe that the problem corresponds to a standard model with one source of demand

intra industry trade in intermediate products pollution and internationally increasing returns this paper examines the relationship between intra industry trade in intermediate products pollution and increasing returns we develop a two country model in which production occurs in two stages final and intermediate good production intermediate goods are produced under monopolistic competition and final good production exhibits increasing returns with respect to the number of varieties of intermediates pollution occurs in the production of the final good when polluting intermediates are used we analyze the effects of international trade in intermediate products on pollution output and welfare under an endogenous tax scenario and with two types of pollution functions the results show that because of increasing returns international trade either leads to lower total pollution in each country or lower pollution per unit of output in at least one country in addition intra industry trade causes countries to import the environmental quality of their trading partners

product differentiation competition and international trade in this paper the two workhorse theories of international trade under imper fect competition krugman s taste for variety model and brander s strategic intra industry trade model are integrated into a single analytical framework a quadratic utility function allows for a nesting of these two theories by postulating a consumer taste for variety over differentiated products where the extent of product differentiation is linked to the intensity of strategic interaction among firms the model yields intuitive predictions on the effects of the degree of product differentiation on the volume of trade and on the composition of the gains from trade under imperfect competition jel classifi cation f12

an approach to evaluate the impact of interaction between demand forecasting method and stock control policy on the inventory system performances abstract usually in stock control studies demand data are considered as an input to the model without explicitly considering that they are the results of a demand forecasting system stock control system is examined independently of the demand forecasting system and it is assumed that demand data or forecast errors have been properly modelled however the interactions that may exist between demand forecasting methods and stock control systems in terms of their effects on global system performances are not considered in the paper an approach for evaluating these interactions based on a comparative simulation test of global system costs using historical data is presented the approach is explained through a real case the replenishment from different suppliers of a central depot of tinned food which supplies more than 700 items to warehouses at the lower echelon results of the simulation study show that traditional measures of forecast errors cannot be taken as sole indicators for the choice among different demand forecasting methods these methods on the contrary have to be evaluated on the basis of total costs and service level of the global inventory control system

dynamic version of the economic lot size model this article originally appeared in management science october 1958 volume 5 number 1 pp 89 96 published by the institute of management sciences a forward algorithm for a solution to the following dynamic version of the economic lot size model is given allowing the possibility of demands for a single item inventory holding charges and setup costs to vary over n periods we desire a minimum total cost inventory management scheme which satisfies known demand in every period disjoint planning horizons are shown to be possible which eliminate the necessity of having data for the full n periods

is trade in permits good for the environment we analyze the impact of trade in emission permits on environmental policy when countries trade a differentiated good pollution is always higher with tradable permits as compared to the case where permits are not internationally tradable if pollution is a pure global public bad i e the marginal damage from transboundary pollution is the same as that from local pollution the permit price under trade equals the domestic marginal damage from own emissions if pollution is not a pure global public bad i e the marginal damage from transboundary pollution is less than that from local pollution trade results in a permit price lower than the domestic marginal damage from own emissions pollution is higher under trade relative to autarky regardless of the nature of transboundary pollution the permit price equivalent pollution tax is lower and pollution is higher with internationally tradable permits than with nontradable permits