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

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

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

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

investments in the dutch onshore wind energy industry a review of investor profiles and the impact of renewable energy subsidies the 2020 renewable energy targets have stimulated the debate on the efficacy of policy schemes discussion on the efficacy of these schemes has largely been on the growth in the share of renewable energy and less on the alignment of policies to the needs of investors however research in this field has emphasized that who is investing is as relevant as how much is invested this study aims to identify and better understand who is investing by researching more than 1000 investments by 646 firms that produce electricity with dutch onshore wind energy these firms received renewable energy subsidies under dutch policy schemes between 1996 and 2013 the regression results highlight the type of investors that invest more in wind energy the results show that firms with a higher wind energy capacity are firms that have more investment experience are latecomers to the wind industry have an industrial background in the electricity or wind industry are medium or large sized and are limited liability companies data on investments combined with a document analysis show that changes in policy schemes affect the perceived risks and expected returns of investors and that these changes influence the amounts invested and the type of investors in wind energy

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

the costs of electricity interruptions in spain are we sending the right signals one of the objectives of energy security is the uninterrupted physical availability of energy however there is limited information about how much is the cost of energy supply interruptions this information is essential to optimize investment and operating decisions to prevent energy shortages or alternatively to determine the strength of the signals to be sent to the agents so that they may invest accordingly in this paper we estimate the economic impact of an electricity interruption in different sectors and regions of spain although there are several caveats in our analysis we find that in 2008 the cost for the spanish economy of one kwh of electricity not supplied was above 4 even in a conservative scenario which is higher than the signals currently being sent as incentives to avoid these interruptions this might result in an underinvestment in short term energy security particularly when we add the usual risk aversion of most consumers

back to the future rethinking auctions for renewable electricity support abstract the effectiveness and cost effectiveness of two main types of instruments feed in tariffs and quotas with tradable green certificates have usually been compared in the literature on renewable electricity promotion due to negative past experiences with a third instrument auctions this instrument has been broadly dismissed in academics and until recently also in policy practice however and based on an in depth review of experiences with auction schemes for renewable electricity around the world this paper argues that some of the problems with auctions in the past can be mitigated with the appropriate design elements and that indeed auctions can play an important role in the future implementation of renewable electricity support instruments around the world the paper provides a proposal for the coherent integration of several design elements

regulatory design for res e support mechanisms learning curves market structure and burden sharing drawing from relevant experiences in power systems around the world this paper offers a review of existing policy support mechanisms for res e with a detailed analysis of their regulatory implications while recent studies provide an account of current res e support systems in this paper we focus on some of the impacts these mechanisms have on the overall energy market structure and its performance given the rising importance of res e in systems everywhere these impacts should no longer be overlooked

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

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

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

combinations of support instruments for renewable electricity in europe a review abstract the aim of this paper is to review the combinations of res e support instruments in the european union eu using different sources of data it is shown that combinations are indeed a widespread phenomenon in the eu member states not much attention has been paid to the combinations of primary instruments with other secondary instruments for the same renewable energy technology it is found that the most frequent mixes of instruments are between feed in laws feed in tariffs and increasingly feed in premiums on the one hand and investment subsidies soft loans and tax incentives on the other in a broad sense the policy mix between primary and secondary instruments has experienced some changes over the last decade mostly related to changes in the primary instruments themselves exclusion i e ineligibility to apply for an instrument when the res e generator is already being financially supported by another instrument and explicit coordination of support under primary and secondary instruments do not seem to be common elements in these policy combinations

imperfections in the economics of public policy imperfections in markets and climate change the economics of public policy has suffered from collective amnesia we have forgotten or ignored much of the tradition of public policy in imperfect economies whose foundations were laid by james meade and paul samuelson this has been associated with a period of around two decades from the early 1980s to the early 2000s where the economics of public policy has bent to political winds and has fed arguments for government to get out of the way and leave everything to the markets to self interest and to self regulation this has manifested itself via the choice of models those which imply often directly from assumptions passive government patterns of teaching the marginalisation of public economies in imperfect economics and compartmentalisation examples in climate change where this amnesia has misled include approaches to discounting and the failure to make non marginal change central to analysis on the other hand creative application of modern public economics gives interesting results such as the possibility of making both current and future generations better off and of informed discussion complementing economic instruments there are strong formal analogies between policy on climate change and on behavioural economics indeed there seems to be great potential in the combination of these two fields jel a10 a12 d61 d62 d63

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

the cost of reducing co2 emissions integrating abatement technologies into economic modeling we explore two methods of incorporating bottom up abatement cost estimates into top down modeling an economy wide method and a sector specific method carbon emissions generally depend on technology and scale given the technology options abatement is possible without a substantial reduction in scale otherwise the change must come purely through a reduction in demand our analysis shows that the cost of environmental policy is considerably overestimated by top down models if a bottom up abatement cost curve is not included using the data for the swiss economy we demonstrate two techniques of representing an abatement function explicitly in a computable general equilibrium model a traditional and a hybrid discrete technology modeling approach the results suggest that the current climate policy in switzerland will not be able to move the economy towards the required 10 co2 reduction both approaches provide virtually the same results when the calibration process is precisely executed which contradicts the results of previous studies

a historical review of promotion strategies for electricity from renewable energy sources in eu countries abstract the core objective of this paper is to elaborate on historically implemented promotion strategies of renewable energy sources and the associated deployment within the european electricity market hence at a first glance the historic development of renewable energy sources in the electricity res e sector is addressed on member state and on sectoral level as well as consequently discussed according to available res e potentials and costs the specific focus of this paper are promotion strategies for res e options as they are the key driver of an efficient and effective res e deployment therefore the paper depicts the main types of different promotion schemes and their properties additionally several cases studies of different european member states show an in depth analysis of the different res e promotion schemes in this context special emphasises are put on the question of effective and efficient promotion scheme designs of different res e technologies generally conducted research led to the conclusion that technology specific financial support measures of res e performed much more effective and efficient than others did hence it is not all about the common question of feed in tariffs vs quota systems based on tradable green certificates but more about the design criteria of implemented res e support schemes

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

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

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

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

will export rebate policy be effective for co2 emissions reduction in china a ceepa based analysis china has adopted cancellation of export tax rebate policies on many occasions to push ahead energy conservation and emission reduction since 2007 by applying a ceepa china energy environmental policy analysis system model this paper simulates the impacts of the cancellation of export rebates on co2 emissions and socio economic consequences in different scenarios so as to figure out whether it works this paper covers three export rebate scenarios and makes comparisons between the impacts of export rebates on emission reduction effects and that of carbon tax policies the conclusions are 1 the current policy which cancels export rebates for key sectors can cut emissions at huge economic cost yet it is unsustainable 2 the policy which cancels export rebates for key sectors and meanwhile subsidizes sectoral outputs yields double dividends in the short term thus can facilitate emission reduction yet the boost is limited 3 the policy which cancels export rebates and boosts domestic demand helps improving residents welfare in the short term while it may inflict pronounced social and economic impacts in the long run so policy of this kind should be adopted with great caution 4 export rebates generate far more economic costs than carbon tax policies in the long term and don t contribute to optimizing the energy mix as well as the latter in summary canceling export rebates should not be regarded as a priority to encourage emission reduction

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

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

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

the choice between emission taxes and output taxes under imperfect monitoring we consider a regulator s choice between environmentally motivated emissions taxes and output taxes we investigate how the optimal instrument depends on the monitoring cost function the firm s technology and on social preferences regarding output and environmental quality pure emissions taxes are usually not optimal with monitoring costs pure output taxes are optimal under sufficiently high monitoring costs sufficiently limited options for emission reduction by means other than output reduction and sufficiently high substitutability of the output finally conditions for the optimality of mixed taxes are given

urban energy transition in china insights from trends socioeconomic drivers and environmental impacts of beijing abstract the coal dominated energy structure has not only fueled china s rapid economic development but also brought great pressure on china promoting energy transition is among the great challenges for china as one of the most developed megacities in china beijing promotes energy transition intensively in this study we explored the trends socioeconomic drivers and environmental impacts of the energy transition process in beijing during the decades we found that beijing s energy transition has gone through four typical stages after a parallel growth between the economy and coal dominated energy consumption at beginning the growth rate of energy consumption has gradually slowed down since 1996 between 2000 and 2007 the energy structure became relatively balanced and diversified driven by the changes of energy intensity energy structure and final demand composition along with the economic structure s shift from heavy manufacturing to service thereafter economic development was seriously decoupled from direct energy consumption and the de coal trend had made remarkable achievements so2 and nox emissions have declined significantly since 2007 diversified energy structure based on the de coal trend cleaner energy and economic restructuring promotes energy transition meanwhile the feasibility of implementation also should be considered in other cities energy transition process in china

age analysis of the impact of a carbon energy tax on the irish economy a computable general equilibrium model with specific detail in taxation and energy use is developed in this paper to quantify the impact of the implementation of energy taxation to reduce carbon dioxide emissions in ireland benchmark data combining physical energy and emissions data and economic data in the form of a social accounting matrix sam had to be compiled from various data sources because energy and pollution accounts from the seea are not available for ireland we find that the reduction target for energy related co2 emissions in ireland of 25 8 compared to 1998 levels can be achieved with a carbon energy tax of 10 15 euros per tonne of co2 though fuel switching is important in meeting the target this result is more sensitive to the possibilities for producers to substitute away from energy use welfare would fall but only by small percentages production and consumption patterns would change more significantly with a shift in demand from fuels with a high emission factor to energy sources with a lower carbon intensity and from energy to other commodities this paper confirms that a carbon energy tax leads to greater emission reductions than an equivalent uniform energy tax the latter has a stronger negative impact on the less polluting energy sectors whereas the carbon tax greatly stimulates the use of renewable energy and reduces the use of peat and coal the new sam the model and the application to energy taxes contribute to a better informed debate on environmental policy in ireland

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

towards a comprehensive policy for electricity from renewable energy an approach for policy design abstract energy policy design in europe is a complex issue involving multiple levels of governance and heavily influenced by institutional contexts however policy design in europe and model based analysis even more so is arguably shaped by the neo classical school of thought there is a need to provide a structured approach that would facilitate the incorporating of institutional contexts into renewable energy sources for electricity res e policy design and analysis this paper presents a formal approach to res e policy design based on design theory the institutional analysis and development iad framework and agent based modelling and simulation given a certain frame of analysis we propose that it is theoretically possible to identify the complete policy design space a set of design elements crucially this aspect potentially opens up to the policy analyst new avenues for intervention and allows her systematically explore given a range of uncertainties which element s of intervention is are the most vital to achieve the goals of the community its empirical applicability is demonstrated by representing and differentiating between six res e schemes from western europe in terms of the design elements a model based illustration demonstrates the value of this approach to quantitatively analyse the impact of design elements

combining bottom up and top down abstract we motivate the formulation of market equilibrium as a mixed complementarity problem which explicitly represents weak inequalities and complementarity between decision variables and equilibrium conditions the complementarity format permits an energy economy model to combine technological detail of a bottom up energy system with a second best characterization of the over all economy our primary objective is pedagogic we first lay out the complementarity features of economic equilibrium and demonstrate how we can integrate bottom up activity analysis into a top down representation of the broader economy we then provide a stylized numerical example of an integrated model within both static and dynamic settings finally we present illustrative applications to three themes figuring prominently on the energy policy agenda of many industrialized countries nuclear phase out green quotas and environmental tax reforms

general equilibrium effects of environmental policy a cge modeling approach estimation of emission control cost functions is often carried out in a partial equilibrium framework i e under the assumption that emission control measures have negligible effects on input and output prices in this paper a computable general equilibrium model is used for simulation of the impact on factor prices and resource allocation of reductions of so infx sup no infx su and co2 emissions thus the model includes markets for tradable emission permits and the equilibrium prices of permits reflect the marginal costs of emission control the results suggest that major emission reductions are likely to have general equilibrium effects and thus that emission control cost functions that fail to take these effects into account may give a distorted picture of the economic impact of emission control

technology and technical change in the mit eppa model potential technology change has a strong influence on projections of greenhouse gas emissions and costs of control and computable general equilibrium cge models are a common device for studying these phenomena using the mit emissions prediction and policy analysis eppa model as an example two ways of representing technology in these models are discussed the sector level description of production possibilities founded on social accounting matrices and elasticity estimates and sub models of specific supply or end use devices based on engineering process data a distinction is made between exogenous and endogenous technical change and it is shown how because of model structure and the origin of key parameters such models naturally include shifts in production process that reflect some degree of endogenous technical change as a result the introduction of explicit endogenous relations should be approached with caution to avoid double counting

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

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

costs of alternative environmental policy instruments in the presence of industry compensation requirements abstract this paper explores how the costs of meeting given aggregate targets for pollution emissions change with the imposition of the requirement that key pollution related industries be compensated for potential losses of profit from the pollution regulation we apply a numerically solved general equilibrium model to compare the incidence and costs of emissions taxes fuel intermediate input taxes performance standards and mandated technologies in the absence and presence of this compensation requirement compensation is provided either through industry tax credits or industry specific cuts in capital tax rates we analyze the added costs from the compensation requirement in terms of 1 an increase in intrinsic abatement cost reflecting a lowered efficiency of pollution abatement and 2 a lump sum compensation cost that captures the efficiency costs of financing the compensation the compensation requirement affects these components differently depending on the policy instrument involved and the required extent of pollution abatement as a result it can change the cost rankings of the different instruments in particular when compensation is provided through lump sum tax credits the lump sum compensation cost is higher under the emissions tax than under the command and control policies performance standards and mandated technologies a reflection of the higher compensation requirements under the emissions tax when the required pollution reduction is modest imposing the compensation requirement causes the emissions tax to lose its status as the least costly instrument and to become more costly than command and control policies in contrast when required abatement is extensive the emissions tax again becomes the most cost effective instrument because of its advantages in terms of lower intrinsic abatement cost

renewable energy policies in europe converging or diverging abstract nations today are urgently challenged with achieving a significant increase in the deployment of renewable energies in europe that need has given rise to a debate about the most effective and efficient support strategy whilst the different interests debate whether full european harmonisation or strengthening of national support policies for electricity from renewable energy sources res e is the best way forward individual national support schemes are rapidly evolving this study investigates how the eu member states have applied support policy types over the last decade by identifying predominant developments in the application of feed in tariffs premiums tradeable green certificates tax incentives investment grants and financing support for specific technologies wind biomass pv this study shows that europe is currently experiencing certain tendencies towards a bottom up convergence of how national policy makers design res e policy supports while some outliers remain the policy supports of most countries become more similar in the policy types applied dominance of feed in tariffs and in their scope of implementation differentiation for installation sizes and stacking of multiple instruments these trends in national decision making which show tendencies of convergence could make an eu driven top down harmonisation of support either dispensable or at least depending on the agreement less controversial

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

dynamic formulation of a top down and bottom up merging energy policy model abstract the impact of energy policy measures is not restricted to the energy system and should therefore be analysed within an economy wide framework while keeping the essential details of the energy sector the aim of this paper is to present new developments in the field of the consistent evaluation of indicators for the sustainability assessment of energy policy measures starting from the static concept of bohringer energy econ 20 1998 233 this paper shows how the complementarity format can be used in computable general equilibrium cge modelling for a dynamic formulation of bottom up and top down approach merging models while a hybrid approach increases the credibility of cge models in energy policy analysis by replacing the energy sector generic functional forms with a bottom up activity analysis based on specific technologies the endogenous formulation of investment decisions makes an explicit description of evolving specific capital stocks and technology mixes possible both features are essential when assessing effects of policy measures that may be affected by structural change which is typically the case in the long term assessment of energy policy measures

when can carbon abatement policies increase welfare the fundamental role of distorted factor markets abstract this paper employs analytical and numerical models to assess the welfare effects of a revenue neutral carbon tax and nonauctioned carbon emissions permits taking into account preexisting tax distortions in factor markets the presence of preexisting taxes significantly raises the general equilibrium costs of both policies this cost increase is much greater under emissions permits since this policy does not generate revenues to reduce distortionary taxes under our central estimates emissions permits cannot increase welfare unless environmental damages exceed about 18 per ton of carbon in contrast an appropriately scaled carbon tax is welfare improving so long as environmental damages are positive

the synthesis of bottom up and top down approaches to climate policy modeling electric power technologies and the cost of limiting us co2 emissions abstract in the us the bulk of co 2 abatement induced by carbon taxes comes from electric power this paper incorporates technology detail into the electricity sector of a computable general equilibrium model of the us economy to characterize electric power s technological margins of adjustment to carbon taxes and to elucidate their general equilibrium effects compared to the top down production function representation of the electricity sector the technology rich hybrid specification produces less abatement at a higher welfare cost suggesting that bottom up models do not necessarily generate lower costs of abatement than top down models this result is shown to be sensitive to the elasticity with which technologies generating capacities adjust to relative prices

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

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

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

decarbonisation perspectives for the polish economy abstract in the coming decades the energy sector in poland will undergo a substantial transition towards low carbon usage which will have a predominant impact on the economy several modernization scenarios for energy policy are currently being discussed by the government and not yet concluded the main objective of this paper is to provide a tool that allows to simulate such scenarios and to show the impact of decarbonisation on the whole economy we propose an intertemporal hybrid general equilibrium modeling that incorporates energy technologies bottom up approach directly into a macroeconomic structure top down approach by accounting for wide adjustments in the economy while controlling for all major constraints the model gives a unique and detailed insight into the future shape of the energy sector and prospects of low carbon economy in poland our simulation results suggest that there are no free lunches no realistic energy mix allows to achieve sustainable positive economic growth when considerable emission reduction is to be achieved the price on co2 will exceed eur 100 for 30 emission reduction with respect to business as usual scenario gradual phase out of coal requires focusing on biomass technology the first best nuclear and wind power the second best

alternative specifications for environmental control costs in a general equilibrium framework abstract we use a computational general equilibrium model to demonstrate that commonly used simplified specifications for environmental control costs do not yield results that are comparable to those obtained when environmental control costs are correctly specified the results indicate that simplified specifications may perform well when the objective is to qualitatively identify sectors disproportionately affected by environmental regulation but not when the goal is to estimate the magnitude of the effects

the role of regulatory learning in energy transition the case of solar pv in brazil abstract an important problem that has attracted significant amount of attention within the context of energy transitions is the carbon lock in a situation in which energy systems are locked in to high carbon technologies through a path dependent process several measures to avoid the carbon lock in involve technology specific measures which in turn implies that those measures may result in an energy system locked in to certain low carbon technologies we consider that the brazilian system needs policies to escape the carbon lock in which are based on providing incentives to low carbon technologies we develop an analytical framework to analyze the role of regulatory institutions in the possible lock in to utility scale photovoltaic in the sense that they create barriers to the adoption of distributed generation photovoltaic we show that the definition of a process to adapt the institutional framework in a context of stress in the innovation system is crucial for the adoption of new technologies applying our framework to the brazilian power sector we observe that only when regulators consider the possibility that the system is locked in to centralized production technologies and not when they just consider the carbon lock in they manage to eliminate barriers to distributed generation based on solar pv

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

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

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

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

expected effects of the ecological tax reform for the polish economy abstract this study presents an assessment of possible consequences of ecological tax reform for the polish economy computable general equilibrium model has been used the model calibrated for the base year 1995 provides results for the year 2005 six different scenarios have been considered final results confirm both theoretical and practical implications of the ecological tax reforms experiences in western european countries the reform is the most favorable when it is based on the concept of shifting tax burden from labor force or households income to environmental pollution long run effects of the proposed tax reform in poland would not slow down the economic growth the reform however has to be implemented as a package of changes in the entire tax system such comprehensive reform could even contribute to economic growth of the polish economy

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

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

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

the applicability of marginal abatement cost approach a comprehensive review abstract the marginal abatement cost mac methodology is widely used in climate change policies policy makers rely on mac to assess feasible strategies and related costs to achieve emission reduction goals this paper introduces a variety of mac methodologies aiming at solving diverse problems which utilizes various calculable logic thus producing different results and implications this study applies a mind mapping method to capture differentiation of mac methods and systematically classify mac methodologies the applicability path analysis was proposed based on principles such as stakeholder type decision making objectives cost concept strategy mode and information scope our goal is to assess the applicability of different methodologies to reduce misuse by policy makers and to serve as a guide for subsequent research which might prompt and lead to the derivation of more consequential results in future studies the results of this study suggest that the complex method is not always better than the simplified method because policy makers are required to select the appropriate method according to the type of information needed it may even be suggested that mac could be reliable by ranking relative value of options compared with baseline rather than focusing on the absolute value of individual measures

north south negotiations on emission reductions a bargaining approach this article models north south negotiations on emission reductions where the north provides side payments in exchange for the south s adoption of a more stringent emission standard we find that depending on where firms compete strong asymmetry among regions the two regions different valuations of side payments and climate change damage can produce self enforcing cooperative agreements moreover the south s optimal standard choice can be one of two polar cases i e either the cleanest or the dirtiest irrespective of the continuum of standards available the results above can also hold true when both parties bargain over the south s emission tax

the costs of the kyoto protocol in the european union we estimate reference co2 emission projections in the european union and quantify the economic impacts of the kyoto commitment on member states we consider the case where each eumember individually meets a co 2 emissions target applying a country wide cap and trade system to meet the target but without trade among countries we use a version of the mit emissions prediction and policy analysis eppa model here disaggregated to separately include 9 european community countries and commercial and household transportation sectors we compare our results with that of four energy economic models that have provided detailed analyses of european climate change policy in the absence of specific additional climate policy measures the eppa reference projections of carbon emissions increase by 14 from 1990 levels the eu wide target under the kyoto protocol to the framework convention on climate change is a reduction in emissions to 8 below 1990 levels eppa emissions projections are similar to other recent modeling results but there are underlying differences in energy and carbon intensities among the projections if eucountries were to individually meet the euallocation of the community wide carbon cap specified in the kyoto protocol we find using eppa that carbon prices vary from 91 in the united kingdom to 385 in denmark welfare costs range from 0 6 to 5 r 2002 elsevier science ltd all rights reserved

risk based assessment of the cost efficiency and the effectivity of renewable energy support schemes certificate markets versus feed in tariffs the introduction of renewable energy sources in the electricity generation mix has the potential to reduce power sector s emissions and countries dependence on imported oil climate change concerns and highly volatile oil prices have attracted governments interest and support to sustain investments in renewable energy capacity and different support policies have been implemented in many countries around the world this paper analyzes the effects of investors risk aversion on the performance of support schemes the analysis compares two policy options a feed in tariff mechanism with a certificate market system results show that while a tariff mechanism could obtain better results than a certificate market its performance is strictly dependent on regulator choices a certificate market instead permits to obtain the desired level of renewable energy market share with good cost efficiency as long as investors risk aversion is moderate moreover discounting future cash flows with higher social discount rates further benefits a certificate system making it preferable to feed in tariffs

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

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

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

a whiter shade of pale on the political economy of regulatory instruments we consider an intertemporal policy game between changing governments that differ in their attitudes towards a particular feature of market outcomes exemplified with environmental pollution when in power a government will choose policy instruments and set strictness of regulation with a view to influencing the policy of future possibly different governments we demonstrate that a brown government favours emission quotas over effluent taxes as quotas establish property rights that are costly to reverse conversely a green government prefers to regulate by taxes in order to limit the incentives of future brown governments to ease regulations strategic behaviour tends to exaggerate policy differences making green governments greener and brown governments browner compared to when such strategic considerations were not an issue jel d81 d9 h23 l51 q28 q38

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

negative externalities and evolutionary implementation in this paper we model externality abatement as an implementation problem our model incorporates techniques from evolutionary game theory assuming that agents dynamically adjust their choices in response to the incentives they currently face we offer a simple condition on aggregate payoffs under which a planner with limited information about preferences can nevertheless ensure that efficient behaviour is globally stable finally we present a series of applications that show that our sufficient condition holds in a variety of models involving negative externalities