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 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

evaluation of land use based greenhouse gas abatement measures in germany abstract agricultural production contributes 11 to the total german greenhouse gas ghg emissions we compare the efficiency of three different land use based ghg abatement measures in combination and as separately applied measures the production of short rotation coppices of feedstocks for biomethane production and peatland restoration we evaluate these options with respect to the following criteria cost efficiency ghg abatement costs abatement potential and impact on agricultural production we use the regional supply model raumis to investigate the different abatement measures at the sector and regional level up to a reduction of ghg emission of 25 1012 g co2eq peatland restoration is the most cost efficient option short rotation coppice allow some cost efficient mitigation also only at limited scale energy maize is only an option if high abatement targets should be met the joint implementation of several abatement strategies allows meeting specified targets at lower costs the crowding out effect between the options is limited the spatial analysis indicates measure specific regional competitiveness and application e g short rotation coppice in eastern and southern germany peat restoration in northern germany and energy maize production in central germany

the economics of forced migration abstract this article reviews the economics literature on the impacts of forced migration the literature is divided into two parts impacts on forced migrants and impacts on host communities studies exploring the impact of forced migration due to wwii suggest that the long term impact is often positive the literature for developing countries suggests that there are serious consequences of forced migration for those forced to migrate these consequences range from worse labour market outcomes to less consumption smoothing the impact on host communities seems to be mixed and there are winners and losers the article provides suggestions for future research

deteriorating inventory model with quantity discount pricing and partial backordering inventory models with quantity discount pricing and partial backordering although common in practice have received very little attention from researchers the objective of this study is to develop a deterministic inventory model with quantity discount pricing and partial backordering when the product in stock deteriorates with time most retailers make pricing decisions of their products at certain times of the year and these decisions affect demand in this study the demand rate is assumed to decrease as price for the product increases unlike traditional inventory models that seek to minimize cost the objective of this study is to maximize profit the findings of this study are particularly relevant to retailers of deteriorating products in a competitive environment a numerical example is given to illustrate the theory

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 hotspots reference routes and research trends of marginal abatement costs a systematic review abstract as one of the most effective means of evaluating environmental policies marginal abatement costs macs have been adopted in a growing body of research this study characterizes the mac related literature from 1993 to 2018 on web of science based on a systematic review bibliometric analysis and mind mapping the results classify the research hotspots into influential factors methods and empirical applications the three most frequently mentioned influential factors are technical change discount rates and energy prices compared with top down models bottom up models including engineering model and expert based method are the most widely used improvements in the former focus on strengthening market behavior effect while those in the latter aim to overcome the weaknesses of negative costs and lack of interaction across measures mac applications focus on environmental policies with two new research areas recently emerging co benefits and sectoral abatement costs furthermore a reference route is proposed by summarizing the applicability of methods and matching relationships among influential factors methods and empirical problems finally potential research directions are summarized based on the identified research hotspots and a similar co word analysis in marginal cost field such as considering the effects of both multiple influential factors and the interaction among factors on maccs

marginal abatement costs of greenhouse gas emissions from european agriculture cost effectiveness and the eu non ets burden sharing agreement abstract we propose a quantitative assessment of the marginal abatement costs mac of greenhouse gas emissions from european agriculture and analyze the implications of the non ets burden sharing agreement bsa for this sector this assessment is based on mac reduced forms the generic specification of which enables simple parameterization and numerical computations such mac curves are parameterized for each member state using the outputs of a detailed model of the european agricultural supply they are then used to compute total and marginal abatement costs involved by the bsa targets as well as the cost effective effort sharing the corresponding emission price and abatement costs the main findings are i flexibility mechanisms such as a cap and trade system for agricultural emissions could reduce the total costs of meeting the 10 eu abatement target by a factor two to three relative to the strict implementation of each country s target ii the corresponding equilibrium emission price is found to be 32 42 tco2eq depending on the assumption regarding business as usual emissions and iii a cap and trade system with allowances based on the bsa targets would involve substantial transfers from eu 15 countries to new member states an important share of which being made of hot air

the eoq models modified by introducing discount of purchase price or increase of setup cost abstract the eoq model of inventory problem can determine ordering cycle and quantity when the purchase unit price is constant ordering cycle and ordering quantity which minimize the one day s average inventory cost is not dependent on the purchase price but if purchase price may change the eoq model must be modified the purchase unit price is discounted as the ordering becomes larger the discount of purchase price is described with a decreasing function of ordering quantity this function is not always continuous with respect to the ordering quantity under this condition one day s average profit can be defined and we can determine ordering cycle and ordering quantity which maximize one day s average profit moreover we consider the situations under which the setup cost depends on the ordering quantity in this case the setup can be described with the increasing function of ordering quantity we show that the eoq model can be applied if it is modified by introducing the continuous setup cost function this function is not differentiable at some levels of ordering quantity

motivations to remit evidence from botswana in this article a theory of motivations to send remittances is described and tested with data from botswana altruism is one of the motivations tested and found to be an insufficient explanation for remittances among migrants in botswana a refinement of the model stipulates a modified altruism or enlightened self interest in this model the relationship between the migrant and family is tempered by an implicit understanding of mutual benefit the household strategy may be to encourage some members to migrate as a means of spreading risk and sharing gains the household strategy is similar to an insurance policy where migration is to places where market potential is high the risks incurred might be high the example is given of migration during a drought in botswana migrant remittances were greater in households with more cattle or households with more to lose drought alone was not statistically related to remittances increases in remittances were related to increased levels of education it is suggested that repayment was the motive for parents investment in migrants education migrants gains are identified as the potential for an inheritance the security of channeling investments through a trusted family member and security in having a home to return to it is pointed out that the altruism and family remittances from urban migration were strategies that bridged the simple dynamic of either urban development or rural development impacting on family welfare it is suggested that household models of economy adopt some measure to express the relationship of household wealth to remittances from urban migrants

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

remittance behaviour of forced migrants in post apartheid south africa this paper looks at the determinants of south south remittances an original dataset of african migrants living in johannesburg is used as south africa attracts both economic and forced migrants we focus on the impact of the reason of emigration violence versus economic concerns on migrants remittance behaviour on the extensive margin the results show that leaving a home country for reasons of violence decreases the probability of remitting to the home country on the intensive margin transferred amounts do not differ according to whether the migrant was forced to migrate or not when the migrant has decided to remit it is more his her current conditions in the host country and traditional factors income education sex etc that determine the amounts transferred our results are robust when restricting the definition of forced migration

an inventory system with demand dependent on both time and price assuming backlogged shortages abstract in this work we analyze an inventory model for items whose demand is a bivariate function of price and time it is supposed that the demand rate multiplicatively combines the effects of a time power function and a price logit function the aim is to maximize the profit per time unit assuming that the inventory cost per time unit is the sum of the holding shortage ordering and purchasing costs an algorithm is developed to find the optimal price the optimal lot size and the optimal replenishment cycle several numerical examples are introduced to illustrate the solution procedure

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

how costly is mitigation of non co2 greenhouse gas emissions from agriculture a meta analysis this text reviews the assessments of marginal abatement costs of methane and nitrous oxide emissions from agriculture we use agricultural emissions and the corresponding prices collected from 21 studies that have assessed abatement potentials and costs using various modeling approaches and assumptions we first highlight the implications of the modeling approach for marginal abatement costs harmonized abatement rates for three emission prices 10 20 and 50 2005 tco2eq are regressed on variables that reflect various modeling assumptions and study characteristics in a second step the emission price is introduced as an explanatory variable when controlling for a few key characteristics of the studies the models explain an important share of the observed variability in abatement rates the type of modeling approach is found to have a significant effect in particular we find that equilibrium models lead to higher abatement rates for a given price the flexibility in nitrogen use and its effect on crop yields also plays a significant role in lowering marginal abatement costs the results of the second step indicate that the price elasticity of the abatement rate is about 0 6 this estimate is found to be robust to several specifications and consistent with previous assessments covering other economic sectors

the economics of immigration this literature review concerns the impact of immigration on the economy of the host country focusing on the experience of the united states the emphasis is on the period from the 1970s to the 1990s the author shows that research earlier in this period generally concluded that the economic effects of immigration were positive but that more recent research on later migrations have generally concluded that immigration may be having an adverse effect on the earnings of native unskilled workers and be placing an increased burden on welfare programs the importance of such economic analysis for the formulation of appropriate migration policies is stressed

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

nitrogen tax and set aside as greenhouse gas abatement policies under global change scenarios a case study for germany the ambitious climate policy objectives of the cop21 agreement require the design and the implementation of effective and efficient policy instruments the effectiveness and efficiency of agricultural abatement options depend on regional climate and natural conditions changes in the global economy global agricultural markets and regional agricultural production thus the assessment of abatement options requires consideration of the global scale the market scale and the regional producer scale we investigate two abatement options discussed controversially in literature both have been partially applied to reduce environmental pollution from agriculture a tax on nitrogen and the obligatory set aside of agricultural land our study provides an assessment of the ecological effectiveness and the economic efficiency of both abatement options under different global scenarios in our policy analysis we combine three applied policy simulation models to develop an integrated economic model framework this model framework considers the global the national and the regional scale and consists of the global general equilibrium model dart bio the partial equilibrium model capri and the regional supply model raumis in the different global scenarios the results show that both abatement options create relatively high marginal abatement costs and that the maximally reached abated greenhouse gas emissions represent only 15 of the quantity required to fulfill the policy targets compared to the obligatory set aside option the nitrogen tax is in both scenarios the more efficient policy with respect to impacts on production and environment a nitrogen tax is less forecastable than the obligatory set aside option our study illustrates the relevance of considering global economic and market change in the assessment of producer targeting environmental policies

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

remittances and the brain drain revisited the microdata show that more educated migrants remit more two of the most salient trends in migration and development over the last two decades are the large rise in remittances and in the flow of skilled migrants however recent literature based on cross country regressions has claimed that more educated migrants remit less leading to concerns that further increases in skilled migration will impede remittance growth micro data from surveys of immigrants in 11 major destination countries are used to revisit the relationship between education and remitting behavior the data show a mixed pattern between education and the likelihood of remitting and a strong positive relationship between education and amount remitted intensive margin conditional on remitting at all extensive margin combining these intensive and extensive margins yields an overall positive effect of education on the amount remitted for the pooled sample with heterogeneous results across destinations the micro data allow investigation of why the more educated remit more showing that the higher income earned by migrants rather than family characteristics explains much of the higher remittances migration brain drain and education

jit purchasing vs eoq with a price discount an analytical comparison of inventory costs abstract the inventory costs of purchasing under economic order quantity eoq model with a quantity discount is determined and compared to the costs under just in time jit it is shown that at low levels of demand jit is the preferred method whereas eoq has the cost advantage for an item with a high demand the model also predicts that the higher the value of the item the carrying cost or the ordering cost associated with the eoq model and the smaller the quantity discount rate the wider will be the range of demand for which jit remains preferable