the carbon footprint of uk households 1990 2004 a socio economically disaggregated quasi multi regional input output model this paper presents a socio economically disaggregated framework for attributing co2 emissions to people s high level functional needs based around a quasi multi regional input output qmrio model the study in theory takes into account all co2 emissions that arise from energy used in production of goods and services to satisfy uk household demand whether the emissions occur in the uk or abroad results show that co2 emissions attributable to households were 15 above 1990 levels in 2004 and that although absolute decoupling occurred between household expenditure and co2 during the uk s switch from coal to gas in the early 1990s since then only slight relative decoupling is evident the proportion of co2 that arises outside uk borders in support of uk consumption is rising and reducing these emissions is particularly problematic in a global trading system investigation into the carbon footprint of different segments of the uk population shows wide variation the segment with the highest carbon footprint emits 64 more co2 than the segment with the lowest results show that recreation and leisure are responsible for over one quarter of co2 emissions in a typical uk household in 2004 we conclude that expanding lifestyle aspirations are significant factors in driving household co2 emissions but the study also emphasizes that attention must be paid to the infrastructures and institutions that result in considerable amounts of co2 being locked up in basic household activities through which people meet their everyday needs for subsistence protection and communication with family and friends the findings highlight the sheer scale of the challenge facing uk policy makers and suggest that policies should be targeted towards segments of society responsible for the highest carbon footprints

perishable inventory theory a review this paper reviews the relevant literature on the problem of determining suitable ordering policies for both fixed life perishable inventory and inventory subject to continuous exponential decay we consider both deterministic and stochastic demand for single and multiple products both optimal and sub optimal order policies are discussed in addition a brief review of the application of these models to blood bank management is included the review concludes with a discussion of some of the interesting open research questions in the area

a deterministic inventory model for deteriorating items with stock dependent demand rate abstract a deterministic inventory model is developed by assuming that the demand rate is stock dependent and the items deteriorate at a constant rate the expression for the average net profit over one production run is derived and its optimization with respect to the decision variables q initial stock and t duration of a production cycle is carried out this leads to two highly nonlinear equations which are solved by using a subroutine neqnf in imsl math library in cyber 180 480a computer system the optimal solution so derived is compared with that for the no deterioration 0 case sensitivity of the optimal solution to changes in parameter values is examined several aspects of the functional form for the demand rate are considered in a separate section finally the salient features of the problem and its solution are discussed in brief

relating the environmental impact of consumption to household expenditures an input output analysis in this paper we evaluate the relationships between household expenditures and the environmental impact categories climate change acidification eutrophication and smog formation by combining household expenditures with environmentally extended input output analysis expenditure elasticities are examined with regression analysis and are compared and interpreted on the basis of insight at the product level with data from the netherlands in the year 2000 we find that environmental impact increases with increasing household expenditures although the degree to which the environmental impact increases differs per impact category climate change and eutrophication increase less than proportionally with increasing expenditures acidification increases nearly proportionally with increasing expenditures whereas smog formation increases more than proportionally it appears that the mix of necessities and luxuries to which an environmental impact is related is essential in explaining the relationship

an economic lot size model with non linear holding cost hinging on time and quantity abstract this paper develops an economic lot size inventory model where the demand rate depends on the stock level and the cumulative holding cost is non linear on both the quantity and the time they are stored more concretely it is supposed that the demand rate is a concave potential function of the inventory level and the holding cost is potential on both time and quantity moreover shortages are not allowed a general procedure to determine the optimal lot size and the maximum inventory profit is developed also some results about the profitability of the inventory system are presented this work extends several inventory models previously considered in the literature finally numerical examples which help us to understand the theoretical results are also given

a multiproduct single machine economic production quantity model for an imperfect production system under warehouse construction cost abstract this paper develops an economic production quantity epq inventory model for a multiproduct single machine lot sizing problem with nonconforming items including scrap and rework where reworks are classified into several groups based on failure severity in this inventory model shortage is allowed and is backordered the aim is to determine the optimal period length the lot size and the allowable shortage of each product so as the total cost including setup production warehouse construction holding shortage reworking and disposal is minimized besides the available total budget is scarce and that there is a lower bound on the service level of each product while the convexity is proved an exact method is proposed to solve the nonlinear programming problem a numerical example is provided at the end to demonstrate the applicability of the proposed solution procedure as well as to perform a sensitivity analysis

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

a note on eoq models for deteriorating items under stock dependent selling rate abstract in 1995 padmanabhan and vrat presented inventory models for deteriorating items with stock dependent selling rate and derived the profit functions without backlogging and with complete backlogging first this paper develops the necessary and sufficient conditions of the existence and uniqueness of the optimal solutions of the profit per unit time functions without backlogging and with complete backlogging second this paper explains that it is appropriate to use the newton raphson method to find the optimal solutions of the profit functions per unit time in both situations modelled

commentary work first workfare and the regulation of contingent labour markets the paper presents a critical review of uk and us welfare to work strategies stressing their implications for changing forms of labour regulation the favoured policy orientation work first forcefully redistributes the risks and burdens of job market instability from the state to unemployed individuals the solution to whose welfare dependency is presented in terms of a one way transition into low waged work at a systemic level the analysis suggests that a regressive regulatory accommodation may be emerging between mandatory welfare to work programming on the one hand and the lowest reaches of deregulated flexible labour markets on the other as the destabilisation of welfare via work activation measures creates a forced labour supply for contingent jobs copyright 2000 by oxford university press

inventory model with stock level dependent demand rate and variable holding cost inventory models in which the demand rate depends on the inventory level are based on the common real life observation that greater product availability tends to stimulate more sales previous models incorporating inventory level dependent demand rate assume that the holding cost is constant for the entire inventory cycle this paper considers the inventory policy for an item with a stock level dependent demand rate and a storage time dependent holding cost the holding cost per unit of the item per unit time is assumed to be an increasing function of the time spent in storage two time dependent holding cost step functions are considered retroactive holding cost increase and incremental holding cost increase procedures are developed for determining the optimal order quantity and the optimal cycle time for both cost structures

optimal ordering and transfer policy for an inventory with stock dependent demand abstract this paper deals with an ordering transfer inventory model to determine the retailer s optimal order quantity and the number of transfers per order from the warehouse to the display area it is assumed that the amount of display space is limited and the demand rate depends on the display stock level the objective is to maximize the average profit per unit time yielded by the retailer the proposed models and algorithms are developed to find the optimal strategy by retailer numerical examples are presented to illustrate the models developed and the sensitivity analysis is also reported

an inventory model for deteriorating items with stock dependent consumption rate and shortages under inflation and time discounting this paper derives an inventory model for deteriorating items with stock dependent consumption rate and shortages under inflation and time discounting over a finite planning horizon we show that the total cost function is convex with the convexity a simple solution algorithm is presented to determine the optimal order quantity and the optimal interval of the total cost function the results are discussed with a numerical example and particular cases of the model are discussed in brief a sensitivity analysis of the optimal solution with respect to the parameters of the system is carried out

an eoq model with stock dependent demand shortage inflation and time discounting abstract this paper develops a finite time horizon deterministic economic order quantity eoq inventory model with shortages where the demand rate at any instant depends on the on hand inventory stock level at that instant the effects of inflation and the time value of money are taken into account considering two separate inflation rates namely the internal company inflation rate and the external general economy inflation rate the results are discussed with a numerical example and particular case of the model is discussed in brief a sensitivity analysis of the optimal solution with respect to the parameters of the system is carried out

an order level lot size inventory model with inventory level dependent demand and deterioration abstract many inventory models have been developed for various deteriorating items with constant demand rate it is a common experience that for perishable consumer goods the age of inventory has a negative impact on the demand due to the loss of consumer confidence on such product consumers tend to keep off perishable items which have reached closer to their expiry dates this paper describes an inventory model in which the demand is considered as a composite function consisting of a constant component and a variable component which is proportional to the inventory level in the periods when there is a positive inventory buildup the rate of production is considered finite and the decay rate as exponential the total cost function is composed of four cost components of all phases of the cycle backorder replenishment inventory buildup inventory depletion and shortage this cost function is later reduced to a two variable function using boundary relations to determine iteratively the set of values of the variables that resulted in minimum cost per cycle the optimum lot size and order level were then obtained with relations established previously results are demonstrated for an instance of the model

a biophysical analysis of the energy real gdp ratio implications for substitution and technical change abstract this paper quantifies the factors that caused the energy real gdp ratio to change during the post war period in france the federal republic of germany japan and the united kingdom econometric results indicate that changes in the types of fuel used changes in the energy consumed by the household sector changes in the types of goods and services produced and changes in energy prices account for most of the variation in this ratio price elasticities estimated from these results are lower than those estimated by neoclassical economists and indicate that the system boundaries used by neoclassical economists overestimate the amount of energy saved by substitution analysis of the error term from the regression results indicates that energy saving technical change has had little effect on the amount of energy used to support economic activity

from production based to consumption based national emission inventories abstract under the united national framework convention of climate change unfccc countries are required to submit national emission inventories nei to benchmark reductions in greenhouse gas ghg emissions depending on the definition and system boundary of the nei the mitigation options and priorities may vary the territorial system boundary used by the unfccc has been critiqued for not including international transportation and potentially causing carbon leakage to address these issues past literature has argued in favour of using consumption based nei in climate policy this article discusses several issues in moving from the standard production based nei to consumption based nei first two distinct accounting approaches for constructing consumption based nei are presented the approaches differ in the allocation of intermediate consumption of imported products second a consistent method of weighting production based and consumption based nei is discussed this is an extension of the previous literature on shared responsibility to nei third due to increased uncertainty and a wide system boundary it may be difficult to implement consumption based nei directly into climate policy several alternative options for incorporating consumption based inventories into climate policy are discussed

environmental kuznets curves real progress or passing the buck abstract recent research has examined the hypothesis of an environmental kuznets curve ekc the notion that environmental impact increases in the early stages of development followed by declines in the later stages these studies have focused on the relationship between per capita income and a variety of environmental indicators results imply that ekcs may exist for a number of cases however the measures of environmental impact used generally focus on production processes and reflect environmental impacts that are local in nature and for which abatement is relatively inexpensive in terms of monetary costs and or lifestyle changes significantly more consumption based measures such co2 emissions and municipal waste for which impacts are relatively easy to externalize or costly to control show no tendency to decline with increasing per capita income by considering consumption and trade patterns the author re examines the concept of the ekc and proposes the use of alternative consumption based measures of environmental impact the author speculates that what appear to be improvements in environmental quality may in reality be indicators of increased ability of consumers in wealthy nations to distance themselves from the environmental degradation associated with their consumption

optimal ordering policy for stock dependent demand under progressive payment scheme abstract in this article a mathematical model is developed to formulate optimal ordering policies for retailer when demand is partially constant and partially dependent on the stock and the supplier offers progressive credit periods to settle the account the notion of progressive credit period is as follows if the retailer settles the outstanding amount by m the supplier does not charge any interest if the retailer pays after m but before second period n offered by the supplier then the supplier charges the retailer on the un paid balance at the rate ic 1 if the retailer settles the account after n then he will have to pay at interest rate ic 2 on the un paid balance ic 2 ic 1 the cost minimization is considered to be an objective function an algorithm is given to find the flow of optimal ordering policy a numerical illustration is given to study the effect of various parameters on ordering policy and total cost of an inventory system

some results for inventory models having inventory level dependent demand rate abstract this paper considers the inventory level dependent demand rate situation in generalized eoq models an interesting result linking the total inventory cost and the optimal policy for such a frame work is obtained and is shown to be consistent for all the models discussed in the paper

proposal of a simple indicator for sustainable consumption classifying goods and services into three types focusing on their optimal consumption levels abstract we calculated optimal consumption patterns of japanese households using a linear programming model taking into account the different environmental burdens to be minimized ninety four industrial sectors and 94 commodities were defined in the model in terms of environmental burdens to be minimized this study considered energy consumption co 2 emission waste and no x emission according to the direction increase or decrease of adjusted final demand for a commodity in the household commodities were classified into three types 1 a commodity for which optimal demand should be decreased in all cases of reducing various environmental burdens 2 a commodity whose optimal demand should be increased in all cases and 3 a commodity whose optimal demand depends on the type of environmental burden among 63 commodities whose final demand was assumed to be adjustable 47 were categorized as commodity type 1 nine were categorized as commodity type 2 and seven belonged to commodity type 3 this work also characterized each type of commodity from the viewpoint of economic and environmental properties

inventory models with inventory level dependent demand a comprehensive review and unifying theory marketing researchers and practitioners have long recognized the demand of many retail items is proportional to the amount of inventory displayed recently two distinct types of inventory control models reflecting this relationship have appeared in the literature models in which the demand rate of an item is a function of the initial inventory level and those in which it is dependent on the instantaneous inventory level we present a comprehensive overview of this literature and demonstrate the equivalence of the two types of models through the use of a simple periodic review model an alternative approach to sensitivity analysis for inventory models with inventory level dependent demand is also presented

note the newsvendor model with endogenous demand this paper considers a firm s price and inventory policy when it faces uncertain demand that depends on both price and inventory level the authors extend the classic newsvendor model by assuming that expected utility maximizing consumers choose between visiting the firm and consuming an exogenous outside option the outside option represents the utility the consumer forgoes when she chooses to visit the firm before knowing whether or not the product will be available the authors investigate both the case in which the firm s price is exogenous and the case in which price is chosen optimally the paper makes two contributions first the authors show that the firm holds more inventories provides a higher fill rate attracts more customers and earns higher profits when it internalizes the effect of its inventory on demand second the authors show that in the endogenous price case the firm s two dimensional decision problem can be reduced to two sequential single variable optimizations as a result the endogenous price case is as easy to solve as the exogenous price case

on the life cycle metaphor where ecology and economics diverge abstract there is an attractive analogy between nature and industry based on the similarity of natural functions and certain industrial activities for instance animals ingest eat and digest food finally there are metabolic wastes firms are analogous to organisms in several respects insofar as they consume material resources process digest them and produce output products and excrete wastes firms like organisms also compete with each other for resources curiously enough one of the apparent differences between natural and man made systems is actually not one like the industrial system the natural system does not recycle everything however there are at least four real and important differences between the biosphere ecology and the technosphere economy first there is no primary producer in the economic system analogous to what photosynthesizers play in the biosphere inputs to the economy are mostly natural resources capital services and labor second in the economic system output is a heterogeneous mix of manufactured products and services labor in economics is an input but not an output the economic system recycles much less than the ecological system but utilizes a far greater suite of elements in the biosphere there are no products as such growth is tantamount to accumulation of embodied solar exergy in the form of cellulose sugars lipids and proteins the biosphere produces only wastes and more of itself plus dead matter third in the biosphere there are no markets there is no medium of exchange like money and there is nothing analogous to paid labor exchanges are involuntary i e by predation parasitism or theft fourth evolution in nature is driven by differentiation by random mutations of the genome and darwinian selection based on reproductive success in economics differentiation is based on discovery invention and innovation by intelligent economic agents and selection is based on competition at the individual or firm level either way the economic system is not closely analogous to an ecosystem attempts to use ecological concepts in an economic context are often misleading and unjustified the paper discusses the implications of the eco eco mismatch for resource accounting and life cycle analysis

an inventory model for deteriorating items with stock dependent demand rate abstract this paper discusses an inventory model with an inventory level dependent demand rate followed by a constant demand rate for items deteriorating at a constant rate where the terminal condition of zero inventory at the end of the scheduling period has been relaxed sensitivity of the decision variables to changes in the parameter values is examined and the effects of these changes on the optimal policy are discussed in brief

the dynamics of willingness to consume abstract it is increasingly acknowledged that the growing consumption in the north constitutes an important part of global environmental problems to improve the possibilities of dealing with this aspect of the problems this paper explores some of the driving forces behind the growth in consumption the first section introduces the environmental debate on consumption including the relationship between final consumption and the consumption of resources the recent political acceptance of dealing with consumption and the fundamental conditions for consumption growth in the north in the following sections a cross disciplinary approach is applied in a broad search for the driving forces behind the willingness to consume throughout the exposition two questions are explored 1 why are productivity increases largely transformed into income increases instead of more leisure 2 why is such a large part of these income increases used for the consumption of goods and services with a relatively high materials intensity instead of less material intensive alternatives the explanations are divided into three groups first the economic explanations including socio economic aspects related to the institutional set up of the economy second socio psychological explanations focusing on consumption from the perspective of the human being embedded in specific social relations third historical and socio technological explanations focusing on different aspects of everyday life the paper concludes with some reflections on the political implications of the analysis

an inventory model with both stock dependent demand rate and stock dependent holding cost rate abstract in this paper we develop an inventory model under a stock dependent demand rate and stock dependent holding cost rate with relaxed terminal conditions shortages are allowed and partially backlogged in the model the purpose of this study is to determine the optimal order quantity and the ending inventory level such that the total profit per unit time is maximized for the retailer we first establish a proper model for a mathematical formulation then we develop several theoretical results and provide the decision maker with an algorithm to determine the optimal solution finally numerical examples are provided to illustrate the solution procedure and a sensitivity analysis of the optimal solution with respect to major parameters is carried out

an extension of inventory models with discretely variable holding costs abstract in a recent paper alfares 2007 inventory model with stock level dependent demand rate and variable holding cost international journal of production economics 108 1 2 259 265 presented an inventory model with a stock dependent demand rate and variable holding costs the analysis imposed a terminal condition that the inventory level at the end of the order cycle drop to zero and utilized a cost minimization objective however with a stock dependent demand rate this approach does not provide an optimal profit allowing ending inventory to be nonzero a profit maximization model and solution methodology are developed computational results indicate a substantial improvement in the solution realized by the proposed approach

increased ecoefficiency and gross rebound effect evidence from usa and six european countries 1960 2002 despite increased efficiency in the use of natural resources the use of these resources continues to increase in most societies this paper examines the discrepancy between the potential decrease of use of natural resources as an effect of increased efficiency and actual use during the period 1960 2002 this difference was found to grow faster in the usa than the mean for six west european countries possible reasons for this difference between the two regions are analysed to reduce the anthropogenic flows of energy and material and the consequent deleterious effects on the biosphere it will become necessary to adapt consumption to degree of efficiency in the use of natural resources based on the comparison between the two regions some economic aspects of this issue are discussed

long term trends in direct and indirect household energy intensities a factor in dematerialisation abstract dematerialisation is assumed to contribute significantly to the alleviation of environmental problems one of the possible causes of dematerialisation is a change in the consumption patterns of households the aim of this article is to analyse changes consumption patterns of dutch households in the period between 1948 to 1996 in order to discover whether these changes haven influenced the energy intensity of society due to the rise in consumption the total household energy requirement per capita grew on average by 2 4 per year over a period of 48 years this figure ignores efficiency changes in the supplying sectors in the same period the total energy intensity of households fluctuated but on average changed from 5 6 to 6 3 mj nlg an increase of 0 25 per year if we exclude the direct energy consumption we find a slight decline in the indirect energy intensity namely from 3 8 to 3 6 mj nlg 0 14 per year no significant trends to a lower energy intensity are found and there is no indication of dematerialisation of the consumption patterns if governments pursue a policy of sustainable development they have to take into account the fact that dematerialisation of the consumption pattern does not seem to be an autonomous process

consumption sustainable welfare and human needs with reference to uk expenditure patterns between 1954 and 1994 abstract this paper explores the complex relationship between economic consumption and human welfare or well being conventional economics suggests that increasing levels of economic consumption lead to increasing levels of well being however this view has been criticised on both environmental and social grounds on the one hand the material impacts of increasing consumption are environmentally unsustainable on the other hand material consumption can conflict with crucial social and psychological components of human welfare this paper develops a perspective on human welfare which is based on max neef s characterisation of human needs it discusses the implications of this alternative perspective for the conventional viewpoint and illustrates the importance of it with reference to patterns of consumer expenditure in the uk over the last 40 years the authors suggest that from this perspective modern societies may be seriously adrift in their pursuit of human well being however they also point out that addressing this situation provides far more opportunity for ecologically sustainable development than is generally recognised

from mass production to flexible specialization the sectoral and geographical extent of contract work in us manufacturing 1963 1997 e ssletzbichler j 2003 from mass production to flexible specialization the sectoral and geographical extent of contract work in us manufacturing 1963 1997 reg studies 37 753 771 over the last two decades much work in economic geography focused on a fundamental reorganization of capitalist production summarized as shift from fordist mass production to flexible specialization complementing this shift to flexible forms of production is the revival of interest in marshallian industrial districts characterized by geographically localized and tightly linked networks of small firms many a claim was based on anecdotal evidence in selected industries and regions in order to strengthen the importance of these results it is necessary to provide comprehensive empirical evidence across a broad range of sectors and regions this paper traces the key developments in economic geography and examines empirically the extent of flexible specialization in us manufacturing more specifically the paper focuses on

an inventory model with deteriorating items under inflation when a delay in payment is permissible abstract this study develops an inventory model for initial stock dependent consumption rate when a delay in payment is permissible in the inventory model shortages are not allowed the effect of the inflation rate deterioration rate initial stock dependent consumption rate and delay in payment are discussed in the study mathematical models are also derived under two different circumstances i e case i the credit period is less than or equal to the cycle time for settling the account and case ii the credit period is greater than the cycle time for settling the account besides expressions for an inventory system s total cost are derived for these two cases moreover a computational procedure and gino lasdon et al acm transactions mathematical software 4 1978 34 50 are proposed to obtain the optimal order size and cycle time the results can help managers determine the optimal total cost finally a numerical example demonstrates the applicability of the proposed model

note an application of the eoq model with nonlinear holding cost to inventory management of perishables abstract in this note we consider a variation of the economic order quantity eoq model where cumulative holding cost is a nonlinear function of time this problem has been studied by weiss weiss h 1982 economic order quantity models with nonlinear holding costs european journal of operational research 9 56 60 and we here show how it is an approximation of the optimal order quantity for perishable goods such as milk and produce sold in small to medium size grocery stores where there are delivery surcharges due to infrequent ordering and managers frequently utilize markdowns to stabilize demand as the product s expiration date nears we show how the holding cost curve parameters can be estimated via a regression approach from the product s usual holding cost storage plus capital costs lifetime and markdown policy we show in a numerical study that the model provides significant improvement in cost vis a vis the classic eoq model with a median improvement of 40 this improvement is more significant for higher daily demand rate lower holding cost shorter lifetime and a markdown policy with steeper discounts

mill s scissors structural change and the natural resource inputs to labour the environmental structural change strategy claims that by shifting our expenditures to economic sectors with lower environmental intensity absolute resource consumption and environmental impact can be lowered environmental input output methodologies for computing these intensities attribute no resource consumption to labour or households because these are not classified as sectors the suggestion that service sectors entail less environmental impact however loses force if a unit of labour contains embodied energy and attributing these inputs to labour drastically reduces intensity variation between sectors relative growth of service sectors has furthermore not been accompanied by decreased resource consumption thus models whose intensity computations cover not only inter firm payments but also labour earnings and household expenditures may have superior predictive power if moreover natural resource and labour inputs to product are incommensurable intensity ratios themselves have perhaps only monetary rather than real significance

looking through the dataquadrate characterizing the human environment relationship through economic hedonic ecological and demographic measures abstract this paper introduces the concept of plotting four dimensional data in two dimensions without loss of information namely the dataquadrate concept here objects are represented as quadrates instead of points in a practical 4 axis cartesian coordinate system this procedure helps us imagine and analyze complex relations where four different non negative variables influence processes this tool is of high utility for analyzing specific human environment issues here we analyze a monetary measure gross domestic product gdp a hedonic measure subjective wellbeing a limiting measure ecological footprint and a demographic measure human population our system adds new insights to the de growth debate discussed in a journal of cleaner production special issue vol 18 2010 and systematically illuminates lots of confusing paradoxes such as the downward sloping part of the environmental kuznets curve the jevons paradox and the easterlin paradox in this paper all these phenomena are analyzed for the usa and for china in 1990 and in 2007 by utilizing such methodology when mitigating environmental problems we are not limited to negative restrictive messages but are enabled to create new strategic ways of problem solving about how to optimize the human celestial footprint the ratio of human wellbeing to human environmental load

technological progress and sustainable development what about the rebound effect abstract sustainability concepts that rest on the idea of resource or energy efficiency improvements due to technological progress tend to overestimate the potential saving effects because they frequently ignore the behavioral responses evoked by technological improvements efficiency improvements also affect the demand for resources and energy and often an increase in efficiency by 1 will cause a reduction in resource use that is far below 1 or sometimes it can even cause an increase in resource use this phenomenon is commonly labeled the rebound effect which is well known among energy economists but never attracted much attention in ecological economics the paper starts with the traditional neoclassical analysis of the rebound effect in a partial equilibrium framework that concentrates on the demand of one particular energy service such as mobility or room temperature it also provides an overview of some of the main empirical studies based on this model that mostly confirm the existence of the rebound effect but are controversial about its actual importance however we have to go beyond the neoclassical single service model in order to take care of the variety of possible feedback affecting energy use the paper presents two important expansions of the single service model in order to show the potential relevance of the rebound effect to ecological economics first it is shown that in a multi services model it proves to be difficult to make general statements about the relevance of the rebound effect in this case the overall effect of an increase in energy efficiency on total energy use depends on the on the assumptions about the substitutability between the services considered and the direction of the income effect second the paper also tries to take care of the fact that changes in resource use or energy use are frequently just side effects of other forms of technological progress especially technological change of a time saving nature can have a large influence on energy use as many time saving devices for example faster modes of transport require an increase in energy consumption that is frequently reinforced by a rebound effect with respect to time this effect will be especially strong when wages are high and at the same time energy prices are low as is currently the case in most industrialized countries consequently the paper also provides a strong argument for the introduction of energy taxes

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

environmentally sustainable household consumption from aggregate environmental pressures to priority fields of action unsustainable consumption patterns of the north or rather of the global affluent consumers class have been identified by agenda 21 as one of the key driving forces behind the unsustainable development however neither accounting based on the system of national accounts sna nor household economics provide the proper instruments to assess the environmental impact of household decision making eco efficiency assessments as familiar in the business sector provide no appropriate tool for households as an alternative an environmental space based assessment scheme is suggested covering the major pressures on the environment caused by household decisions the methodology is used twice once to analyse the environmental relevance of the main activity clusters of household consumption and once to identify the dominant acts of consumption within each cluster the latter provide the basis for deriving environmental performance indicators a rough analysis of household influence potentials permits to identify housing eating and mobility as the three priority fields for action for minimising the environmental impact of households extending the influence analysis actor matrixes are derived allocating influence and thus responsibility for environmental pressures to different groups of economic agents

production inventory models for a damageable item with variable demands and inventory costs in an imperfect production process in this paper economic production quantity epq models for breakable or deteriorating item are developed with variable demands being dependent on time or on hand stock here rate of production and holding cost are time dependent unit production cost is a function of both production reliability indicator and production rate set up cost is also partially production rate dependent the production process produces some imperfect quantities which are instantly reworked at a cost to bring back those units to the perfect ones the production process ultimately depends on both time and reliability indicator the models are formulated as optimal control problems and the total profit functions with effect of inflation and time value of money are expressed as finite integrals over the finite planning horizon the problems are solved using euler lagrange function based on variational calculus and newton raphson method to determine the optimal production reliability indicator r and then corresponding production rates and total profits in some cases results of the models for deteriorating item are obtained as particular cases from those of breakable item models similarly results of simple epq models without damageability are deduced as particular cases numerical experiments are performed to illustrate the models both numerically and graphically

deterministic models of perishable inventory with stock dependent demand rate and nonlinear holding cost this paper deals with an extended eoq type inventory model for a perishable product where the demand rate is a function of the on hand inventory the traditional parameters of unit item cost and ordering cost are kept constant but the holding cost is treated as i a nonlinear function of the length of time for which the item is held in stock and ii a functional form of the amount of the on hand inventory the approximate optimal solution in both the cases are derived computational results are presented indicating the effects of nonlinearity in holding costs

energy requirements of households in brazil abstract in this study we determine the total direct plus indirect energy requirements of a given set of brazilian households we use a generalized input output model in order to calculate the energy embodied in goods and services purchased by households of different income level in 11 capital cities of brazil our results show that on average the total energy intensity of household expenditure increases with income level although there is a considerable spread in energy intensities within income classes as well as disparities between regions of the country the total yearly average energy requirement per household in brazil in 1995 96 was 173 6 gj 61 of which was indirect with 32 8 gj for the lower income level 66 of which was indirect and 602 2 gj for the higher income level 62 of which was indirect of this total average energy requirement 76 was required for only three consumption categories utilities 31 mobility 28 and shelter 17 this analysis calls for the attention that has to be given not only to the direct energy consumption as motor fuels and electricity for example but also to the consumption categories that encompass an important part of the indirect energy requirement of households in capital cities in brazil

an optimal production inventory model for deteriorating items with multiple market demand the global markets of today offer more selling opportunities to the deteriorating items manufacturers but also pose new challenges in production and inventory planning from a production management standpoint opportunities to exploit the difference in the timing of the selling season between geographically dispersed markets for deteriorating items are important to improving a firm s profitability in this paper we examined the above issue with an insightful production inventory model of a deteriorating items manufacturer selling goods to multiple markets with different selling seasons we also provided a solution procedure to find the optimal replenishment schedule for raw materials and the optimal production plan for finished products a numerical example was then used to illustrate the model and the solution procedure finally sensitivity analysis of the optimal solution with respect to major parameters was carried out

economic order quantity models with nonlinear holding costs abstract we consider a generalization of the classical economic order quantity model the traditional parameters of unit cost selling price demand rate and set up cost are constant but the holding cost per unit is a non linear function of the length of time the item is held in stock the application is to any inventory system where the value of the item decreases non linearily the longer it is held in stock for the case of deterministic demands we present the cost formula and the optimal order quantity for both finite and infinite horizons for the case of stochastic demands the cost function is examined and the optimal order amount is presented computational results are presented indicating the effect of the non linearity in holding costs

demand promotion by upgradation under stock dependent demand situation a model the idea of demand promotion by upgrading the existing system of the selling centre has been modelled in this article the consumption rate is assumed to be dependent on the stock level the problem has been reduced to a maximizing problem the algorithmic approach for solving this maximizing problem is also provided objective is to maximize the net profit over a prescribed time an increasing convex upgradation cost is considered exponential upgradation cost has been considered for the numerical examples

an optimal procurement policy for items with an inventory level dependent demand rate and fixed lifetime abstract this paper investigates an optimal procurement policy for items with an inventory level dependent demand rate and fixed lifetime the demand rate is assumed to be a function of current inventory level and each unit has its fixed expiry date so any units which remain unused by their expiry date are considered outdated and must be disposed of for the system presented a mathematical model and solution methodology were developed sensitivity of the decision variables to changes in the parameter values is examined and future research needs are discussed in brief

a two echelon inventory distribution system with power demand pattern and backorders abstract this paper addresses the implications of considering power demand pattern and backorders in the one warehouse n retailer problem specifically we assume that items at the retailers are withdrawn from the inventory following a power pattern the objective function consists of the sum of ordering holding and backordering costs at all installations this objective function depends on the class of inventory policies that we choose for the formulation of the problem in general obtaining the cost function is an arduous task since the average inventory at the warehouse could be difficult to determine however if we apply single cycle policies the computation of the total average cost becomes possible under these assumptions we show that the one warehouse n retailer system with power demand pattern and backorders can be formulated as a mixed non linear programming problem

is energy cost an accurate indicator of natural resource quality abstract the use of energy cost as an indicator of natural resource quality is examined energy cost is the direct and indirect energy used to produce a unit of a resource commodity different approaches to the role of energy in the economy are discussed and it is demonstrated theoretically that energy cost can give false indications of changes in resource quality this is because energy cost is only an accurate indicator of resource quality if either energy is the single primary factor of production and the economy can be represented by an input output model or if there is substitutability between the factors of production then marginal products must be proportional to the factors embodied energy these conditions are tested empirically using data from the us agricultural sector the results show that there is substitutability and marginal products are not proportional to embodied energy however the strong neoclassical assumption of price taking profit maximization can be rejected at a 5 level of significance though not at the 3 5 level the generality of the empirical results may be restricted due to data limitations but the theoretical framework can be applied to other data sets other resources and even other indicators

eoq models with general demand and holding cost functions abstract we consider the continuous deterministic infinite horizon single item inventory system within the setting of a retail sector in which the demand rate for an item is dependent on the existing inventory level the traditional parameter of the replenishment cost is kept constant but the carrying cost per unit is allowed to vary two possibilities of variation are considered a a non linear function of the length of time the item is held in inventory and b a non linear function of the amount of on hand inventory we find the optimal policies and decision rules and show that the classical eoq model is obtained as a limiting case

ecological sufficiency individual liberties and distributive justice implications for policy making we investigate the prospects of voluntary ecological sufficiency for environmental and climate policy under the constraints implied by political liberalism we find that freedom of choice restricts sufficiency to rather wealthy societies and that a sufficiency threshold cannot be derived by referring to the poor sufficiency can be in conflict with the demands of social justice i e if the sufficiency threshold is below the social minimum implied by social justice benefits from sufficiency are highly related to individual perceptions such benefits cannot be expressed in a standard preference framework consequently alternative measures of welfare and inequality are required if sufficiency is a significant phenomenon in society standard environmental policies can have a pronounced interaction with voluntary sufficiency i e if quantity regulation is present overall the voluntary notion of sufficiency causes a dilemma as sufficiency is largely a matter of civil society however voluntary sufficiency is expected to make important contributions to the preservation of ecological resources if properly balanced with social and environmental policies and framed by public discursive control

the transition to flexible specialisation in the us film industry external economice the division of labour and the crossing of industrial divides there is increasing evidence that mass production methods are losing their dominance in the advanced industrial economies and that various forms of flexible production organization are on the rise the transition from mass production organization to flexible specialization is analyzed in detail through a case study of the film industry where it is shown that a system of production once based on product standardization high levels of vertical integration and stable oligopolistic market structures has after a period of vertical disintegration given way to a production system based on a deep division of labor between firms and high levels of flexibility in both product design and output levels the transition may be the result of increasing external economies of scale stemming from the development of the industry s social division of labor copyright 1989 by oxford university press