is protectionism on the rise assessing national trade policies during the crisis of 2008 to understand the role of trade policies in the crisis of 2008 this paper constructs the overall trade restrictiveness indices for a wide range of countries using their tariff schedules in 2008 and 2009 the index summarizes the trade policy stance of a country taking into account the share of each good in trade as well as its corresponding import demand elasticity results show that there is no widespread increase in protectionism via tariff policies since the global financial crisis has unfolded while many countries have adjusted tariffs upward on selected products only a handful of countries such as malawi russia argentina turkey and china focus on products that have significant impacts on trade flows the united states and the european union by contrast rely mainly on anti dumping duties to shield domestic industries overall while the rise in tariffs and anti dumping duties in these countries may have jointly caused global trade to drop by as much as us 43 billion during the crisis period it explains less than 2 percent of the collapse in world trade

evaluating jointly constrained order quantity complexities for incremental discounts abstract in this paper we consider the purchasing decisions facing a buying firm which receives incrementally discounted price schedules for a group of items in the presence of constraints such as budgets and space limitations the constraints take the form of upper bounds on positively weighted linear combinations of order size dollar volume unit price and order frequency we adapt the solution procedures from an earlier paper naval res logis 40 2 1993 255 to treat this case the results show that simultaneous order quantities for multiple items offered with separate incremental discounts and subject to joint resource constraints can be calculated efficiently using a combination of lagrangean relaxation and as needed partial enumeration this problem proved to be no more and no less tractable than its counterpart with all units discounts

an improved model for supplier selection under capacity constraint and multiple criteria abstract ghodsypour and o brien 2001 the total cost of logistics in supplier selection under conditions of multiple sourcing multiple criteria and capacity constraint international journal of production economics 73 1 15 27 study multiple sourcing problem with multiple criteria and capacitated suppliers considering the buyer s quality requirements as a constraint they develop a mixed integer non linear programming model to find the least cost cyclic ordering policy for the buyer they propose to solve the model by enumerating over all possible supplier combinations although the problem is interesting and their analysis is correct we point out two issues with their assumptions namely capacitated suppliers and cyclic ordering policy we discuss two different capacitated supplier settings i long run average annual capacity and ii exact annual capacity first under long run average annual capacity assumption we propose a model which provides the same or a better solution and is much easier to solve than their model then we discuss how to modify our and their models to handle exact annual capacity assumption

modeling a multi attribute utility newsvendor with partial backlogging abstract traditional newsvendor models usually focus on single profit maximization or cost minimization approaches however making a monetary estimate of the consequences of lost sales as a result of shortages is often a difficult task for many practitioners besides there is still a lack of an explicit account of decision making judgments on the multiple consequences of making decisions with regard to order quantities in order to deal with this problem this paper presents a multi attribute utility model for the newsvendor problem with regard to profit the impacts of service level on corporate image and on customers goodwill and the impact on the environment arising from the disposal of unsold products demand is partially backlogged according to a decreasing exponential function of the waiting time the fundamental principles and limitations related to the application of the model built are also discussed

an economic order quantity model with partial backordering and all units discount abstract the classic economic order quantity model assumes that the unit purchasing cost is not based on the order quantity in practice a supplier may offer purchasers an all units discount we develop a model and solution procedure for the eoq with all unit discounts and partial backordering at a constant rate we show and illustrate with a numerical example how that model can be used to find the solution for the eoq with discount and full backordering a multi factor experiment is used to gain insights into the improvement in performance of the proposed procedure relative to using the basic eoq or the eoq with full backordering and to identify the model parameters that have the greatest impact on the model s performance

replenishment decisions under an all units discount schedule and stepwise freight costs in this study we analyze the replenishment decisions under a general replenishment cost structure that includes stepwise freight costs and all units quantity discounts we first formulate a general model that accounts for a larger class of problems and prove several useful properties of the expected profit function we later utilize these properties to develop a computational solution approach to find the optimal order quantity as an application of the general results we study the replenishment decisions in the single period i e the newsboy problem considering several scenarios that model the cost considerations either for the buyer or for both the buyer and the vendor

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

note comment on a generalized quantity discount pricing model to increase supplier s profits lee and rosenblatt lee h l m j rosenblatt 1986 a generalized quantity discount pricing model to increase supplier s profits management sci 32 9 1177 1185 considered the joint problem of ordering and offering discount by a supplier to his sole buyer the objective of the supplier being to induce the buyer to alter his order quantities in order to increase the supplier s yearly profit they determined the optimal ordering and pricing policy for the supplier under the constraint on the amount of discount offered to the purchaser this restriction on the amount of price discount seems unreasonable when the objective of the supplier in all likelihood is to increase his own profits it is possible that higher discounts in purchase price may lead to greater economies for the supplier in this note a much simpler approach is being offered for determining the optimal ordering and pricing policy for the supplier

a heuristic for single warehouse multiretailer supply chains with all unit transportation cost discounts abstract in supply chain management research transportation costs if explicitly considered at all are frequently assumed to be linear these costs often have a more complex form such as an all unit discount structure this piecewise cost function adds significant complexity when included in supply chain management problems and is therefore often ignored due to solution time or tractability concerns we present and evaluate a new heuristic procedure which provides good solutions to problems involving all unit discount cost functions while significantly reducing solution times the general nature of this procedure does not require assumptions about the supply chain structure or policies and is therefore applicable in a wide range of settings

planning and approximation models for delivery route based services with price sensitive demands abstract classical vehicle routing problems typically do not consider the impact of delivery price on the demand for delivery services existing models seek the minimum sum of tour lengths in order to serve the demands of a given set of customers this paper proposes approximation models to estimate the impacts of price on delivery services when demand for delivery service is price dependent such models can serve as useful tools in the planning phase for delivery service providers and can assist in understanding the economics of delivery services these models seek to maximize profit from delivery service where price determines demand for deliveries as well as the total revenue generated by satisfying demand we consider a variant of the model in which each customer s delivery volume is price sensitive as well as the case in which customer delivery volumes are fixed but the total number of customers who select the delivery service provider is price sensitive a third model variant allows the delivery service provider to select a subset of delivery requests at the offered price in order to maximize profit

incorporating transport cost in the lot size and pricing decisions with downward sloping demand abstract there is an increased emphasis in supply chain management on making all costs transparent this has led to greater scrutiny of freight costs by the resellers who want to control their inbound logistics costs an astute reseller may opt for paying freight when he sees an opportunity for savings in some cases a supplier may only sell on conditions of fob origin in this paper we consider a reselling situation wherein the final demand is sensitive to the selling price and the reseller is responsible for paying for the freight given that transportation costs can be almost 50 of the logistics cost s r swenseth m r godfrey int j prod econ 77 2002 113 there is a need for coordination between the reseller s purchasing function and his pricing policy in this study we formulate a model for determining the optimal lot size and the selling price for the reseller existing models for the problem have treated freight breakpoints in the same way as price breakpoints in a quantity discount schedule in doing so they have ignored the option of over declaring the weight of the shipment which is routinely available to the buyer shipper in practice in this paper we assume that the reseller has such an option we also assume that in setting the size of the order shipment the reseller can choose between less than full truckload or full truckload shipment

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

a classification of literature on determining the lot size under quantity discounts abstract determining a lot size in the presence of either all units or incremental discounts has represented one of major interests of materials managers it is a common practice that the suppliers offer quantity discount to entice the buyers to purchase more and to achieve economies of scale for transportation and processing costs this paper will classify the literature on lot sizing determination under several types of discount schemes and discuss some of the significant literature in this area over two decades also some future research areas have been identified

the impact of regulations on agricultural trade evidence from the sps and tbt agreements according to world trade organization rules countries may adopt regulations under the agreements on sanitary and phyto sanitary sps and technical barriers to trade tbt we analyze the structure of these measures in agricultural trade the inventory approach suggests that european countries have among the lowest coverage ratios of all oecd countries using a gravity equation we also estimate their stringency our results suggest that they significantly reduce developing countries exports to oecd countries but do not affect trade between oecd members furthermore european imports are more negatively influenced by sps and tbts than imports of other oecd countries

analysis and applications of replenishment problems under stepwise transportation costs and generalized wholesale prices abstract in this study we analyze the replenishment decision of a buyer with the objective of maximizing total expected profits the buyer faces stepwise freight costs in inbound transportation and a hybrid wholesale price schedule given by a combination of all units discounts with economies and diseconomies of scale this general cost structure enables the model and the proposed solution to be also used for the supplier selection of a buyer under the single sourcing assumption we show that the buyer s replenishment problem reduces to finding and comparing the solutions of the following two subproblems i a replenishment problem involving wholesale prices given by an all units discount schedule with economies of scale and a lower bound on the replenishment quantity and ii a replenishment problem involving wholesale prices given by an all units discount schedule with diseconomies of scale and an upper bound on the replenishment quantity we propose solution methods for these two subproblems each of which stands alone as practical problems and utilize these methods to optimally solve the buyer s replenishment problem

quantity discounts under demand uncertainty to motivate buyers to increase their order quantity suppliers often rely on a well established and widely used approach they offer quantity discounts this practice is in large part driven to obtain improved economies in transportation through higher truckload utilization recently transportation rates which are increasing faster than other costs have become a larger portion of total net landed cost placing the traditional quantity discount practices under scrutiny many suppliers are left perplexed as to why their approach is not effective anymore and some are even concerned that their overall profits may have actually decreased due to their discount parameters in this paper we study a multiperiod model with a buyer facing stochastic end item demand and a supplier offering an all units quantity discount to him to understand better the dynamics of such systems we provide guidelines and insights on how to set effective discount parameters and when not to expect much from them we derive the opt

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

the concave cost supply problem abstract this paper is divided in two parts in the first part we consider the case where several providers feed a single manufacturing unit periodically in order to satisfy a given demand the cost incurred when a provider feeds the manufacturing unit is a concave function of the quantity delivered furthermore each provider either delivers a quantity that lies between a minimum and maximum value or do not deliver anything we are introducing some properties of an optimal solution and derive a heuristic algorithm from these properties a numerical example illustrates this approach in the second part of the paper we consider the case where several providers feed periodically several manufacturing units in order to satisfy given demands a heuristic algorithm is proposed the results provided by this algorithm are compared with the optimal solution in the case when the costs are linear for a strictly positive quantity and equal to zero otherwise

heuristics for sourcing from multiple suppliers with alternative quantity discounts in this paper we analyze the impact of supplier pricing schemes and supplier capacity limitations on the optimal sourcing policy for a single firm we consider the situation where the total quantity to be procured for a single period is known by the firm and communicated to the supplier set in response to this communication each supplier quotes a price and a capacity limit in terms of a maximum quantity that can be supplied to the buyer based on this information the buyer makes a quantity allocation decision among the suppliers and corresponding to this decision is the choice of a subset of suppliers who will receive an order based on industry observations a variety of supplier pricing schemes from the constituent group of suppliers are analyzed including linear discounts incremental units discounts and all units discounts given the complexity of the optimization problem for certain types of pricing schemes heuristic solution methodologies are developed to identify a quantity allocation decision for the firm through an extensive computational comparison we find that these heuristics generate near optimal solutions very quickly data from a major office products retailer is used to illustrate the resulting sourcing strategies given different pricing schemes and capacity limitations of suppliers in this industry we find for the case of capacity constrained suppliers the optimal quantity allocations for two complex pricing schemes linear discount and incremental units discount are such that at most one selected supplier will receive an order quantity that is less than its capacity

protectionism during the crisis tit for tat or chicken games abstract we explore the extent to which the adoption of protectionist measures during the recent financial crisis led to retaliation by trading partners we find no evidence of retaliation on the contrary there is strong evidence of chicken games being played

gender quotas and the quality of politicians we analyze the effects of the introduction of gender quotas in candidate lists on the quality of elected politicians as measured by the average number of years of education we consider an italian law which introduced gender quotas in local elections in 1993 and was abolished in 1995 as not all municipalities went through elections during this period we identify two groups of municipalities and use a difference in differences estimation we find that gender quotas are associated with an increase in the quality of elected politicians with the effect ranging from 0 12 to 0 24 years of education this effect is due not only to the higher number of elected women who are on average more educated than men but also to the lower number of low educated elected men the positive effect on quality is confirmed when we measure the latter with alternative indicators it persists in the long run and it is robust to controlling for political ideology and political competition

note comments on a quantity discount pricing model to increase vendor profits monahan monahan j p 1984 a quantity discount pricing model to increase vendor profits management sci june 720 726 adapted the quantity discount model of inventory theory to the problem of determining an optimal quantity discount schedule from a vendor s point of view and opened up an important direction of research however his one item one customer one vendor model is based on several implicit assumptions that must be judged unreasonable monahan must account for the vendor s inventory carrying charges and redefine his variable s2 it is shown that a rational vendor s manufacturing frequency would not be identical to the buyer s ordering frequency if the vendor s manufacturing setup costs are substantially larger than the buyer s ordering costs a numerical example presented in this note also questions the practical usefulness of monahan s model even after its theoretical inaccuracies axe corrected monahan s model may explain discounts that are a fraction of 1 of the price of an item but it fails to explain commonly observed magnitudes of quantity discounts such as 10 of the unit price

import protection business cycles and exchange rates evidence from the great recession this research estimates the impact of macroeconomic fluctuations on import protection policies over 1988 q1 2010 q4 for five industrialized economies the united states european union australia canada and south korea there is evidence of a strong countercyclical trade policy response in the pre great recession period of 1988 q1 2008 q3 during which increases in domestic unemployment rates real appreciations in bilateral exchange rates and declines in the gdp growth rates of bilateral trading partners led to substantial increases in new temporary trade barriers it then applies this pre great recession empirical model to realized macroeconomic data from 2008 q4 2010 q4 and find it predicts a surge of new import protection during the great recession e g for the us and eu the model predicts new trade barriers would cover an additional 15 percentage points of nonoil imports well above the baseline level of 2 3 percent of import coverage immediately preceding the crisis finally the research examines why the realized trade policy response differed from model predictions while exchange rate movements played an important role in limiting new import protection during the great recession there is also evidence of one particularly important change in trade policy responsiveness i e in this period governments refrained from imposing new temporary trade barriers against foreign trading partners experiencing their own weak or negative economic growth

economic lot size model for price dependent demand under quantity and freight discounts abstract previous studies have developed procedures which determine optimal lot size and selling price when demand depends on price and all unit quantity discounts are offered further recent studies have addressed the concepts of quantity and freight discounts for constant demand in this paper we incorporate quantity and freight discounts in inventory decision making when demand rather than being constant is considered to be dependent upon price an algorithm is developed to determine the optimal lot size and selling price for a class of demand functions including constant price elasticity and linear demand a numerical example is provided to illustrate the model and a computer program is developed to implement the model derived in the paper

multi product lot sizing with a transportation capacity reservation contract abstract although transportation costs can form more than 50 of the total logistics costs of a product they are often neglected in lot sizing research and modelling nonetheless the body of research that does take transportation costs into account is gradually growing the bulk of this type of research however assumes that freight rates decrease as shipping weights and or volumes increase inspired by the situation with a large european manufacturing company we study a multi product lot sizing model where in any period any portion of a reserved transportation capacity can be used in exchange for a guaranteed price if the capacity is insufficient then the shipper needs to contract additional transportation capacity on the spot market where the prevailing price is higher accordingly the freight rates are piece wise linearly increasing in our model we prove that the problem of determining transportation lot sizes so as to meet warehouse demand with no backlogging allowed and to minimize total costs that is the sum of inventory carrying ordering and transportation costs is np hard in the strong sense furthermore we present a lagrangean relaxation algorithm to compute lower and upper bounds of which comprehensive computational experiments show the compelling performance in terms of quality and speed

a note on an economic lot size model for price dependent demand under quantity and freight discounts abstract in this study we revisit research contributed by burwell et al 1997 international journal of production economics 48 141 155 where an economic lot size model for price dependent demand under quantity and freight discounts was proposed specifically for the cases of mixed discounts in which the quantity discounts are either of the incremental or all units variety and the freight discounts are of the opposite type we first provide counterexamples to show that adopting the existing algorithm to determine overall optimal lot size and selling price may not achieve the goal of maximizing profit we then propose an easy to understand computational algorithm to obtain an exact solution

joint inventory replenishments with group discounts based on invoice value the study focuses attention on a grouping procedure for the purpose of joint inventory replenishments from a single supplier the grouping procedure exploits the group discounts available on the total purchase value of a group of index and the economies of scale of order placing costs in particular it is shown that the optimal groups are formed such that the annual dollar usage values of the items do not decrease may increase or stay the same from the first to the last group this is similar in concept to the well known abc classification of inventory items the grouping problem is modeled as a shortest path using the above property

a generalized discount structure and some dominance rules for selecting the price break eoq abstract this paper introduces a generalized discount structure that combines the features of incremental and all units quantity discount policies general properties of the eoq model under this discount structure are studied and dominance rules for comparing order quantity intervals under either type of discount policy are established in addition procedures for developing an iso cost function and the minimal feasible set for optimal order quantity are proposed

the march of an economic idea protectionism isn t counter cyclic anymore conventional wisdom holds that protectionism is counter cyclic tariffs quotas and the like grow during recessions while that may have been a valid description of the data before the first world war it is now inaccurate since the second world war protectionism has not been counter cyclic tariffs and non tariff barriers simply do not rise systematically during downturns i document this new stylised fact with a panel of data covering over 180 countries and 40 years using over a dozen measures of protectionism and six of business cycles i test and reject a number of potential reasons why protectionism is no longer counter cyclic a diagnosis of exclusion leads me to believe that modern economics may well be responsible for the decline in protectionism s cyclic behaviour economists are more united in their disdain for protectionism than virtually any other concept this in turn leaves one optimistic that the level of protectionism will continue to decline along with its cyclicality andrew k rose

shared resource capacity expansion decisions for multiple products with quantity discounts abstract when multiple products compete for the same storage space their optimal individual lot sizes may need to be reduced to accommodate the storage needs of other products this challenge is exacerbated with the presence of quantity discounts which tend to entice larger lot sizes under such circumstances firms may wish to consider storage capacity expansion as an option to take full advantage of quantity discounts this paper aims to simultaneously determine the optimal storage capacity level along with individual lot sizes for multiple products being offered quantity discounts either all units discounts incremental discounts or a mixture of both by utilizing lagrangian techniques along with a piecewise linear approximation for capacity cost our algorithms can generate precise solutions regardless of the functional form of capacity cost i e concave or convex the algorithms can incorporate simultaneous lot sizing decisions for thousands of products in a reasonable solution time we utilize numerical examples and sensitivity analysis to understand the key factors that influence the capacity expansion decision and the performance of the algorithms the primary characteristic that influences the capacity expansion decision is the size of the quantity discount offered but variability in demand and capacity per unit influence the expansion decision as well furthermore we discover that all units quantity discounts are more likely to lead to capacity expansion compared to incremental quantity discounts our analysis illuminates the potential for significant savings available to companies willing to explore the option of increasing storage capacity to take advantage of quantity discount offerings for their purchased products

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

quantity discounts managerial issues and research opportunities marketing managers frequently administer pricing policies involving substantial quantity discounts however our understanding of the precise role of these discounts and their design is quite limited this paper reviews and integrates the economics and marketing literature and presents a detailed analysis of the policies of four firms in order to i specify the variety of motivations for quantity discounts ii provide guidelines to managers in designing quantity discount schedules and iii set out the most fruitful directions for future research

multi buyer discount pricing abstract this article gives an exact optimal solution to the problem of finding the optimal discount price and price break quantity for a seller dealing with one buyer it also gives a method for solving the problem when one seller offers a single quantity discount schedule to many buyers the discount is of the all quantity type and the model of the cost structure was originally proposed by crowther

trade standards and poverty evidence from senegal summary in the debate on trade and poverty it is argued that standards act as trade barriers and cause marginalization of the poor this paper quantifies income and poverty effects of high standards trade and integrates labor market effects by using company and household survey data from the vegetable export chain in senegal we find that exports grew sharply despite increasing standards contributing importantly to rural incomes and poverty reduction tightening standards induced a shift from smallholder contract farming to integrated estate production altering the mechanism through which poor households benefit through labor markets instead of product markets

the impact of sanitary and phytosanitary measures on market entry and trade flows in an attempt to disentangle the impact of sanitary and phytosanitary sps measures on trade patterns we estimate a heckman selection model on the hs4 disaggregated level of trade we find that aggregated sps measures constitute barriers to agricultural and food trade consistently to all exporters but conditional on market entry trade flows are positively affected by sps measures additionally we find that sps measures related to conformity assessment hamper market entry and trade flows while sps measures related to product characteristics pose an entry barrier but increase bilateral trade flows conditional on meeting the standard

an incremental discount pricing schedule with multiple customers and single price break abstract this paper analyzes how a supplier can formulate the terms of a quantity discount pricing schedule assuming a single incremental discount system a model is developed from which an algorithm is derived for an optimal discount schedule the cases are investigated in which both the discount rate and the break point are unknown and either one is prescribed a numerical example is presented to illustrate the algorithm developed

hidden protectionism evidence from non tariff barriers to trade in the united states abstract can the enforcement of product standards be protectionism in disguise this paper estimates the costs of non compliance with u s product standards using a new database on u s import refusals from 2002 to 2014 we find that import refusals decrease exports to the united states this trade reducing effect is driven by developing countries and by refusals without any product sample analysis in particular during the subprime crisis and its aftermath we also provide evidence that given product standards were enforced more strictly during the crisis while the quality of imported products did not deteriorate these results are consistent with the existence of counter cyclical hidden protectionism due to non tariff barriers to trade in the united states

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

improving the efficiency of the purchasing process using total cost of ownership information the case of heating electrodes at cockerill sambre s a improving the efficiency of the purchasing process provides important opportunities to increase a firm s profitability in this paper we introduce a mathematical programming model that uses total cost of ownership information to simultaneously select suppliers and determine order quantities over a multi period time horizon the total cost of ownership quantifies all costs associated with the purchasing process and is based on the activities and cost drivers determined by an activity based costing system our approach is motivated by the purchasing problem of heating electrodes at cockerill sambre a belgian multinational steel producer in this case quality issues account for more than 70 of the total cost of ownership making the quality of a supplier a critical success factor in the supplier selection process

note on a quantity discount pricing model to increase vendor profits monahan monahan james p 1984 a quantity discount pricing model to increase vendor profits management sci 30 june 720 726 develops a model for establishing an optimal quantity discount schedule from a vendor s viewpoint in this note we show that this model is limited to the case where the vendor buys from another supplier incorporating vendor s inventory carrying costs we develop a generalized version of monahan s model and demonstrate its equivalence with the joint economic lot size approach suggested by banerjee banerjee avijit 1986 a joint economic lot size model for purchaser and vendor decision sci 17 summer 292 311

the value of the revolving door political appointees and the stock market abstract we analyze stock market reactions to announcements of political appointments from the private sector and corporate appointments of former government officials using unique data on corporate affiliations and announcements of all senate confirmed u s defense department appointees of six administrations we find positive abnormal returns for political appointments these estimates are not driven by important observations volatile stocks industry wide developments or the omission of further commonly used return predictors placebo events for close competitors and alternative dates yield no effects effects are larger for top government positions and less anticipated announcements we also find positive abnormal returns for corporate appointments and positive effects of political connections on procurement volume our results suggest that concerns over conflicts of interest created by the revolving door seem justified even in a country with strong institutions

multi item single source ordering problem with transportation cost a lagrangian decomposition approach as a part of supply chain management literature and practice it has been recognized that there can be significant gains in integrating inventory and transportation decisions the problem we tackle here is a common one both in retail and production sectors where several items have to be ordered from a single supplier we assume that there is a finite planning horizon to make the ordering decisions for the items and in this finite horizon the retailer or the producer knows the demand of each item in each period in addition to the inventory holding cost an item base fixed cost associated with each item included in the order and a piecewise linear transportation cost are incurred we suggest a lagrangean decomposition based solution procedure for the problem and carry out numerical experiments to analyze the value of integrating inventory and transportation decisions under different scenarios

optimal policy for an inventory system with backlogging and all units discounts application to the composite lot size model this paper examines an inventory model with full backlogging and all units quantity discounts the practical scenario of a salesperson offering compensation to a client so as not to lose the sale is considered the cost of a backorder thus includes both a fixed cost and a further cost which is proportional to the length of time the said backorder exists a first algorithm is developed to determine the optimal policy while some extensions to this algorithm are obtained that include additional conditions on the model in particular the well known composite lot size model developed by tersine is solved incorporating a new stockout cost and a new all units discount numerical examples are provided to illustrate the application of the algorithms

making do with less working harder during recessions why did productivity rise during recent recessions one possibility is that average worker quality increased a second is that each incumbent worker produced more the second effect is termed making do with less using data from 2006 to 2010 on individual worker productivity from a large firm these effects can be measured and separated for this firm most of the gain in productivity during the recession was a result of increased effort additionally the increase in effort is correlated with the increase in the local unemployment rate presumably reflecting the costs of losing a job

technical regulations and specialization in international trade abstract it is widely acknowledged that while technical regulations can improve welfare and facilitate markets they can also impede trade the trade impeding effects of technical regulations are especially worrisome for developing countries they frequently lack the human and capital resources necessary to satisfy technical measures and thus are more likely to be excluded from markets by technical measures this paper uses highly disaggregated us data on agricultural mining and manufacturing imports to examine the impact of technical regulations on trade patterns using instrumental variables estimation to correct for the potential endogeneity of technical regulations the analysis suggests that technical regulations substantially impinge on poor countries exports their weaker capacities to satisfy technical regulations lead them to specialize away from industries with heavier regulatory burdens

incorporating quantity discounts to the eoq model with transportation costs abstract this article extends a previous economic order quantity eoq model with two modes of transportation namely truckload tl and less than truckload ltl carriers by introducing all units and incremental quantity discount structures into the analysis exact algorithms are developed for each quantity discount structure to compute optimal policies for single stage models over an infinite planning horizon

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

production and shipment lot sizing in a vendor buyer supply chain with transportation cost abstract previous research on the joint vendor buyer problem focused on the production shipment schedule in terms of the number and size of batches transferred between the two parties it is a fact that transportation cost is a major part of the total operational cost however in most joint vendor buyer models the transportation cost is only considered implicitly as a part of fixed setup or ordering cost and thus is assumed to be independent of the size of the shipment as such the effect of the transportation cost is not adequately reflected in final planning decisions there is a need for models involving transportation cost explicitly for better decision making in this study we analyze the vendor buyer lot sizing problem under equal size shipment policy we introduce the complete solution of the problem in an explicit and extended manner that has not existed in the literature we incorporate transportation cost explicitly into the model and develop optimal solution procedures for solving the integrated models all unit discount transportation cost structures with and without over declaration have been considered numerical examples are presented for illustrative purpose

the constitutional economics of autocratic succession the paper extends and empirically tests gordontullock s public choice theory of the nature of autocracy a simple model of the relationship between constitutional rules governing succession in autocratic regimes and the occurrence of coups against autocrats is sketched the model is applied to a case study of coups against monarchs in denmark in the period ca 935 1849 a clear connection is found between the specific constitutional rules governing succession and the frequency of coups specifically the introduction of automatic hereditary succession inan autocracy provides stability and limits the number of coups conducted by contenders

strategic gerontocracy why nondemocratic systems produce older leaders one characteristic of nondemocratic regimes is that leaders cannot be removed from office by legal means in most authoritarian regimes no institutional way of dismissing incompetent rulers is available and overthrowing them is costly anticipating this people who have a say in the selection of the leader are likely to resort to alternative strategies to limit his tenure in this paper we examine empirically the strategic gerontocracy hypothesis because selecting aging leaders is a convenient way of reducing their expected time in office gerontocracy will become a likely outcome whenever leaders are expected to rule for life we test this hypothesis using data on political leaders for the period from 1960 to 2008 and find that dictators have shorter life expectancies than democrats at the time they take office we also observe variations in the life expectancies of dictators those who are selected by consent are on average closer to death than those who seize power in an irregular manner this finding suggests that gerontocracy is a consequence of the choice process since it disappears when dictators self select into leadership positions

electoral rules and political selection theory and evidence from a field experiment in afghanistan voters commonly face a choice between competent candidates and those with policy preferences similar to their own this article explores how electoral rules such as district magnitude mediate this trade off and affect the composition of representative bodies and the quality of policy outcomes we show formally that anticipation of bargaining over policy causes voters in elections with multiple single member districts to prefer candidates with polarized policy positions over more competent candidates results from a unique field experiment in afghanistan are consistent with these predictions specifically representatives selected by elections with a single multi member district are better educated and exhibit less extreme policy preferences

incorporating quantity discounts and their inventory impacts into the centralized purchasing decision multi site organizations must balance conflicting forces to determine the appropriate degree of purchasing centralization for their respective supplies the ability to garner quantity discounts represents one of the primary reasons that organizations centralize procurement this paper provides methodologies to calculate optimal order quantities and compute total purchasing and inventory costs when products have quantity discount pricing procedures for both all units and incremental quantity discount schedules are provided for four different strategic purchasing configurations scenarios complete decentralization centralized pricing with decentralized purchasing centralized purchasing with local distribution and centralized purchasing and warehousing for ordering decisions under local distribution procedures to determine optimal order quantities and costs are presented in a precise form that could be easily implemented into spreadsheets by practicing managers for the more complicated multi echelon scenarios we introduce a single cycle policy with a tailored aggregation refinement step that performs very well under experimentation when compared to a conservative bound