economies of scale in energy use in adult only households the residential sector is responsible for 18 of australia s primary energy use thus improved knowledge about household energy use is vital to future energy management this study examines economies of scale in energy use and expenditure among adult only households and across three adult only household types significant economies of scale are found in all cases small households suffer a double penalty of greater per capita energy use and higher charge per unit of energy with older households the most affected the trend towards smaller average household size means that economies of scale are continually being lost offsetting gains in energy efficiency achieved through other means

optimal pricing shipment and payment policy for an integrated supplier buyer inventory model with two part trade credit abstract in this article we develop an integrated supplier buyer inventory model with the assumption that the market demand is sensitive to the retail price and the supplier adopts a trade credit policy the trade credit policy discussed in this paper is a two part strategy cash discount and delayed payment that is if the buyer pays within m1 the buyer receives a cash discount otherwise the full purchasing price must be paid before m2 where m 2 m 1 0 the objective of this research is to determine the optimal pricing ordering shipping and payment policy to maximize the joint expected total profit per unit time an iterative algorithm is established to obtain the optimal strategy furthermore numerical examples and sensitivity analysis are presented to illustrate the results of the proposed model and to draw managerial insights

integrated inventory models considering the two level trade credit policy and a price negotiation scheme abstract this paper develops the integrated inventory models with permissible delay in payment in which customers demand is sensitive to the buyer s price the models consider the two level trade credit policy in the vendor buyer and buyer customer relationships in supply chain management a simple recursive solution procedure is proposed for the integrated models to determine the buyer s optimal pricing and production order strategy although the total profit from the buyer and vendor increases together the buyer s share lessens to compensate the buyer s loss due to the cooperative relationship a negotiation system is presented in order to allocate the profit increase to the vendor and buyer to determine the pricing and production order strategy a numerical example and sensitivity analysis are provided to illustrate the proposed model the results indicate that the total profit from the buyer and vendor together can increase although a price discount is given to the buyer in the proposed models

optimal economic ordering policy with deteriorating items under different supplier trade credits for finite horizon case abstract this paper develops and solves a general finite horizon trade credit economic ordering policy for an inventory model with deteriorating items under inflation and time value of money when shortages are not allowed the time horizon is divided into different cycles each of which has its own demand rate and its own trade credit period offered from the supplier to his retailer so that the retailer should pay his supplier before or after the end of the permissible trade credit of that cycle up to the end of the trade credit of a cycle the retailer is free of charge but he is charged on an interest for those items not being sold before this end the retailer can also earn the interest of the money from the generated sales revenue in any cycle by depositing such revenue into an interest bearing account the objective of the retailer is then to minimize his net total relevant costs a closed form of this net total cost is derived and the resulting model is solved then rigorous mathematical methods are used to show that under some seemingly possible conditions there exist a unique vector of the relevant decision variables that solve the underlying inventory system a numerical example which shows the applicability of the theoretical results is given

energy consumption and urban sprawl evidence for the spanish case residential electricity consumption constitutes one of the largest sources of spanish final energy demand to improve electricity savings policies oriented towards efficiency in residential consumption such as replacement of appliances or the construction of nearly zero energy buildings have been suggested and implemented however the potential relevance of urban structural characteristics such as the increase in detached houses in sprawling residential areas has not often been considered the aim of this research is to analyse the relevance of living in a detached house located in a dispersed urban area to household electricity consumption thus an electricity consumption model is estimated by using household socioeconomic variables and including urban characteristics as its determinants such us the level of urban agglomeration or whether families live in detached sprawling homes the model is estimated by using 2014 household budget survey hbs microdata and applying ordinary least squares ols as well as quantile regressions qr as econometric procedures endogeneity problems are corrected by means of instrumental variables the results confirm that living in a detached house significantly increases electricity consumption whereas urban agglomerations have the opposite effect sprawl is occurring rapidly in spanish cities and according to our results it could constitute a relevant source of increase in electricity demand in the following years

the optimal ordering policy of the eoq model under trade credit depending on the ordering quantity from the dcf approach abstract this paper discusses the optimum order quantity of the eoq model that is not only dependent on the inventory policy but also on firm credit policy here the conditions of using a discounted cash flows dcf approach and trade credit depending on the quantity ordered are discussed we consider that if the order quantity is less than at which the delay in payments is permitted the payment for the item must be made immediately otherwise the fixed trade credit period is permitted this paper incorporates all concepts of a discounted cash flows dcf approach trade credit and the quantity ordered and develops a new inventory model to generalize chung chung k h 1989 inventory control and trade credit revisited journal of the operational research society 40 495 498

country level analysis of household fuel transitions abstract solid fuel combustion remains a dominant energy source for household heating and cooking in less developed countries as a result almost three billion people are exposed to household air pollution causing four million premature deaths annually primarily among poor women and children we analyze data from demographic and health surveys in 69 countries to identify determinants of transition from solid to cleaner fuel estimates from a population averaged linear model show that population density and size rural population share income inequality and charcoal production are positively associated with countries solid fuel use while gdp per capita electricity and natural gas production have the opposite effect economic development measured as gdp per capita has the strongest link to solid fuel use a standard deviation increase in per capita gdp above its mean reduces solid fuel use from 70 to 57 of households electricity production is another strong predictor solid fuel use drops by 11 when electricity production increases by one standard deviation above the mean in addition in a fixed effects linear model population size has a positive association with solid fuel use while increases in gdp per capita and the number of governments renewable energy incentives are associated with lower dependence on solid fuels

governing the transition to natural gas in mediteranean metropolis the case of cairo istanbul and sfax tunisia recent scholarship on urban energy governance has focused on low carbon energy strategies seen as a response to climate change and energy pressure threats but such approaches tend to overlook the situations of cities from the global south and emerging countries concerned with strong energy demand growth the development of urban natural gas networks is an understudied response to such a challenge focusing on three cities istanbul cairo and sfax tunisia the article analyses the factors and the governance of these energy transitions it uses a geographical approach to such processes that highlight the mutual influence of the territory in its material and political dimensions and of the policy goals and tools in the implementation the development of urban gas networks rests upon the proximity of gas deposits it is determined by metropolitan strategies for economic development as well as by programs aiming to cut energy subsidies though urban gas networks have a strong potential for restructuring the physical and social landscapes in cities the dominant commercial approach taken by energy utilities and morphological constraints in the urban fabric limit their universalization natural gas is part of a mix of energies at the urban level and often competes with other energy forms specifically renewables like solar water heaters lastly the development of urban natural gas networks sparks heated politics in relation to unfulfilled energy demand and affordability

a review of trade credit literature opportunities for research in operations abstract trade credit arises when a buyer delays payment for purchased goods or services its nature has predominantly been an area of inquiry for researchers from the disciplines of finance marketing and economics but it has received relatively little attention in other domains in our article we provide an integrative review of the existing literature and discuss conflicting study outcomes we organize the relevant literature into seven areas of inquiry and analyze four in detail trade credit motives order quantity decisions credit term decisions and settlement period decisions additionally we derive a detailed agenda for future research in these areas

spectrum auctions yesterday s heresy today s orthodoxy tomorrow s anachronism taking the next step to open spectrum access abstract the auction paradigm for spectrum allocation has moved from heresy to orthodoxy but like its predecessors it will not be the end of history a better alternative not driven by the revenue needs of government is license free spectrum users would gain entry to frequency bands on a pay as you go basis instead of controlling a slice of the spectrum they would transmit their content together with access tokens these tokens are electronic money access prices would vary with congestion set by automatic clearinghouses of spectrum users spot and futures markets for spectrum access would emerge once technology and economics can solve the interference problem in ways other than exclusivity the question arises whether the right to use the spectrum for electronic speech is the government s to sell in the first place

optimal strategy for an integrated system with variable production rate when the freight rate and trade credit are both linked to the order quantity abstract this paper presents an integrated inventory model with variable production rate and price sensitive demand rate the buyer s purchases trade credit linked to the order quantity offered by the supplier in addition the buyer pays the freight charge according to a weight schedule this paper attempts to offer a best policy that aims at maximizing the joint total profit while the trade credit and freight rate are simultaneously linked to the order quantity the same policy also incorporates considerations on the optimal retail price order quantity and delivery decision we provide possible solutions for the buyer and the supplier to collaboratively agree on inventory control warehouse management transportation logistics delivery and billing our study demonstrates that significant profit increase for the entire supply chain can be achieved by linking both trade credit policy and freight rate policy to order quantities an algorithm is furnished to determine the optimal solution in addition numerical examples and sensitivity analysis are presented to illustrate the theoretical results

economic and demographic determinants of household energy use in turkey this paper analyzes several economic and socio demographic factors which affect households energy choices in turkey the data is obtained from the household budget surveys hbs conducted by the turkish statistics institute tuik the multinomial logit model is used to identify households energy choices the most important finding of the study is that monthly income of households or household welfare in general has significant effect on energy choices it is also important to note that ages of persons have influence on energy choices indeed health concerns easiness in use was found as criteria referred to particularly by household heads at age 50 and over when making energy choices as far as settlements are concerned the most salient characteristic of urban dwellers vis a vis rural dwellers is their dominant preference for natural gas while rural dwellers have their choice for more conventional fuels

an incentive compatible solution for trade credit term incorporating default risk abstract this paper studies the optimal trade credit term decision in an extended economic ordering quantity eoq framework that incorporates a default risk component a principal agent bilevel programming model with costs minimization objectives is set up to derive the incentive compatible credit term the supplier determines the credit term as the leader in the first level programming by balancing her his financing capacity with the retailer s default risk order behavior and cost shifting at the second level the retailer makes decisions on ordering and payment time by reacting on the term offered by the supplier a first order condition solution procedure is derived for the bilevel programming when credit term is confined within the practically feasible interval two key results are obtained the condition to derive incentive compatible credit term and an equation system to derive threshold default risk criterion filtering retailers suitable for credit granting numerical experiments show that the capital cost of the supplier is the most important factor determining the credit term default risk acts like a filtering criterion for selecting retailers suitable for credit granting empirical evidence supporting our theoretical considerations is obtained by estimating three panel econometric models using a dataset from china s listed companies

cooking fuel choice in rural china results from microdata abstract unclean cooking fuel is widely used in the developing world and it is the main indication of energy poverty in rural china in this paper we investigate the situation transition and determination of fuel choice in china s rural household cooking using the large scale micro survey data of china health and retirement longitudinal study charls we find that there is a big gap in using commercial cooking fuels between rural and urban households 60 of the rural households adopt traditional biomass resource as their main fuel for cooking in 2011 while this figure is less than 5 in the urban we also identify a significant spatial divide in fuel choice in southeastern coastal areas about 40 of the rural households prefer solid fuels while this figure jumps to over 80 in northeastern areas the longitudinal data also reveal a significant transition from traditional to modern fuels from 2008 to 2012 moreover the distance to the most commonly used farmer s market education background coal price and female labor participation are all influential in determining the households choices

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

household fuel use in developing countries review of theory and evidence because of recent concerns about the negative externalities of traditional fuel use on the environment and health the issue of the household fuel transition in developing countries from dirty fuels towards clean fuels has received growing research attention this paper provides an up to date survey of the economic literature on household fuel use in these countries first we present the conceptual and theoretical frameworks then we discuss the empirical results that show how a wide range of factors drive the household fuel transition finally we suggest priorities for policy initiatives and highlight areas of future research

impact of trade credit and inflation on retailer s ordering policies for non instantaneous deteriorating items in a two warehouse environment with the advent of better technologies in manufacturing and retail industry consumer beliefs and needs have been altered supermarkets are expected to sell fresh products in good conditions which have a longer shelf life or do not begin to deteriorate immediately termed known as non instantaneous deteriorating items this characteristic is now usually observed in almost all food stuffs fashionable items electronic products among others in order to sustain in the retail sectors the managers are moving forward to store these items in warehouses moreover due to increasing competition in business world supplier offers a permissible delay in payments to retailer in order to increase demand this encourages the retailer to order a large quantity which in turn entitles the organization to rent out an additional storage space considering the importance of such a scenario the present research work develops a two warehouse inventory model for non instantaneous deteriorating items with permissible delay in payments under inflationary conditions shortages are allowed and partially backlogged since customers willingness to wait decreases over time the objective of this paper is to determine the retailer s optimal replenishment policies that maximize the present worth of total optimal profit per unit time finally the proposed inventory model has been validated with the help of numerical example sensitivity analysis of the optimal solution with respect to key parameters of the inventory system has been also presented which provides important managerial implications

administrative creation of property rights to radio spectrum abstract despite the 1934 communication act s ban on private ownership of radio spectrum the law leaves open to the federal communications commission a range of licensing regimes under which the commission may in its discretion grant spectrum users relatively strong or weak property rights to allotted frequencies this article examines numerous administrative decisions by the fcc to demonstrate how regulatory changes have affected the property interests conferred by spectrum licenses focusing on licensees rights to use divide and broker spectrum flexibly and to prevent unauthorized reception of their signals the article discusses the economic and legal significance of those changes and identifies areas for further reform the authors conclude that although important changes remain to be made the fcc has strengthened property interests on both the transmission and receiving ends of licensed frequencies and through the administrative process has eroded the importance of the statutory distinction

factors determining household use of clean and renewable energy sources for lighting in sub saharan africa abstract the purpose of the current research is to examine the factors that influence household use of determinants of renewable and clean energy sources used for lighting purposes in africa using the data from the living standard measurement study lsms from three african countries ethiopia tanzania and malawi for this purpose the paper uses multinomial logit and ordered probit econometrics models the descriptive analysis reveals that rural households are dependent largely on kerosene and batteries for lighting their houses while electricity and batteries form a major source of energy for lighting urban households a small fraction of households uses solid fuels and solar as their source of energy for lighting econometric results show that female headed households are likely to adopt clean and renewable sources of energy compared to male headed households wealthier and more educated households are found to use electricity and solar energy for lighting while poorer households tend to use kerosene batteries and solid fuels empirical results indicated that the ethiopian households followed by malawian households are more likely to use clean sources of energy compared to tanzanian households

modeling household energy expenditure in the united states abstract energy consumption is one of the main source of air pollution greenhouse gas emission and global warming reducing household energy consumption is a key goal of policymakers we develop statistical models using socio economics and demographics building characteristics location temperature and energy prices to estimate household energy expenditure in the u s we use household energy expenditure for more than 560 000 households in the u s from 2010 to 2012 we first employ multivariate regression models to investigate and identify the impacts of the explanatory variables on household energy expenditure next we use principal component analysis pca to convert correlated co linear explanatory variables into orthogonal components and estimate household energy expenditure by principal component regression we find newer attached buildings to be effective in decreasing household energy expenditure particularly among educated people in metropolitan areas with sufficient data availability our model could be used by state regional or even city level policymakers and planners to optimize their infrastructural investments

spectrum flash dance eli noam s proposal for open access to radio waves abstract as ronald coase posited in his famous article on the nature of the firm there are situations in which decentralized markets are relatively efficient for coordinating economic activity and situations in which they are not with spectrum access assigning property rights to clearly specified private owners is the socially efficient policy because the relevant transaction efficiencies will be internalized by competitive spectrum owners selecting to what degree rights should be subdivided and in what manner marketed where spot markets are optimal an owner will maximize profits by using them where long term contracts are efficient the owner will enter profitably into them hence eli noam s solution imposing open access rules on bands of radio frequencies by government mandate is a mistaken attempt to duplicate the efficiencies of markets by mandating a particular subset of market solutions such a policy predictably will result in underutilization of the spectrum resource

household energy choice and consumption intensity empirical evidence from bhutan abstract this paper uses data from three bhutan living standard surveys blss 2003 blss 2007 and blss 2012 to examine the trends and patterns of household energy consumption and identify and analyze the factors that influence household energy choices consumption intensity and the per capita household expenditure on energy sources in bhutan during the last decade significant numbers of bhutanese households have switched to cleaner energy sources empirical results show that a household s choice of cleaner energy sources is driven by income level and household wealth the age gender and education of the household heads access to electricity and location education and income have a differential role on the choice of clean or dirty fuel wealthier and more educated households use and rely more on clean sources of energy like electricity and liquid petroleum gas while poorer households use and rely on dirty fuel such as fuelwood and kerosene the study shows that female headed households are more likely to choose cleaner fuels and above all the availability of a clean and cost effective source of energy within proximity to the household is an important factor in the adoption of clean energy several models using a variety of alternative independent variables such as proxies for education and wealth were estimated and confirmed the robustness of the results

an eoq model under retailer partial trade credit policy in supply chain abstract the main purpose of this paper is to investigate the retailer s inventory policy under two levels of trade credit to reflect the supply chain management situation in this paper we assume that the retailer has the powerful decision making right so we extend the assumption that the retailer can obtain the full trade credit offered by the supplier and the retailer just offers the partial trade credit to his her customer then we investigate the retailer s inventory system as a cost minimization problem to determine the retailer s optimal inventory policy under the supply chain management two easy to use theorems are developed to efficiently determine the optimal inventory policy for the retailer we deduce some previously published results of other researchers as special cases finally numerical examples are given to illustrate the theorems and obtain a lot of managerial phenomena

the rationality of u s regulation of the broadcast spectrum in his classic 1983 technologies of freedom ithiel de sola pool so elucidated the prevailing wisdom concerning broadcast licensure in the united states while the key legal questions surrounding this institution involve important first amendment questions hence pool s scarcity analogy to paper ink and presses economists and other policy analysts have often remarked on the more general incongruity in federal licensing while spectrum is regulated on the physical scarcity premise it is awarded to private users on a no fee basis thus conferring significant economic rents on private parties at substantial opportunity cost to the fisc moreover federal communications commission fcc 2 policies have openly sought virtually throughout the agency s entire life span to restrict broadcast licenses and competition for broadcasters particularly cable television to far below the quantity technically available 3 the

investment in competitive equilibrium the optimality of myopic behavior there is an extensive literature on the optimal irreversible investment strategy of a solitary firm facing an exogenous price process this paper shows that the investment strategies that this literature derives may be optimal in competitive equilibrium even though the price process is now endogenous this provides a simple means for computing equilibrium investment strategies

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

determinants of household energy consumption in india improving access to affordable modern energy is critical to improving living standards in the developing world rural households in india in particular are almost entirely reliant on traditional biomass for their basic cooking energy needs this has adverse effects on their health and productivity and also causes environmental degradation this study presents a new generic modelling approach with a focus on cooking fuel choices and explores response strategies for energy poverty eradication in india the modelling approach analyzes the determinants of fuel consumption choices for heterogeneous household groups incorporating the effect of income distributions and traditionally more intangible factors such as preferences and private discount rates the methodology is used to develop alternate future scenarios that explore how different policy mechanisms such as fuel subsidies and micro financing can enhance the diffusion of modern more efficient energy sources in india

a ladder within a ladder understanding the factors influencing a household s domestic use of electricity in four african countries abstract according to the energy ladder hypothesis electricity is at the top of the energy ladder of household energy use that depends primarily on wealth status income and education levels of the users however it is often observed that households with higher income wealth and education levels do not use electricity for all domestic activities such as lighting heating and cooking creating a ladder within a ladder using a comprehensive data set from the living standard measurement study from four african countries ethiopia malawi tanzania and uganda covering 17 000 households this paper investigates the factors determining a household s adoption of electricity for lighting only and for lighting and cooking the results of a multinomial logit model and an ordered probit model show that demographic characteristics a household s wealth and human capital access to markets and remoteness greatly accelerate a household s use of electricity for light and cooking which provides evidence of a ladder within a ladder

adapting inventory models for handling various payment structures using net present value equivalence analysis beullens patrick univ southampton southampton so17 1bj hants england janssens gerrit k univ southampton southampton sch management southampton so17 1bj hants england janssens gerrit k hasselt univ res grp logist b 3590 diepenbeek belgium

implementing a market based spectrum policy abstract the spectrum auctions were a step toward the herzel coase vision of a flexible and efficient market for spectrum this article examines what remains to be done spectrum must be unbundled from broadcast and transmission facilities the commoditization of spectrum will facilitate standardization price discovery and open access to diverse users a liquid secondary spectrum market will lower transactions and entry cost making telecommunications markets contestable auctions should be used to elicit a supply of spectrum from licensees as well as to allocate it to new users in closing the spectrum commons congress granted use to a privileged few unbundled spectrum property rights commoditization and open markets will give the public access to this public resource

spectrum property law 101 abstract regulatory doctrine holds that radio spectrum licensees do not have private property rights in their licenses in fact as shelanski and huber show most of the basic attributes of private property are possessed in some measure by all licensees this practical reality has been obscured by the official ideology of public interest obligation attached to spectrum use however public interest regulation has always been marginal in practical effect but public interest ideology reinforced by interest group politics has prevented full realization of the market efficiencies that could be achieved from explicit recognition of spectrum property rights the true public interest lies in removing obstacles to efficient use of the radio spectrum and allowing it to seek its highest valued use to the public spectrum auctions may help to move us in the direction of a less burdened market system but they are only a step not the destination

property rights and wireless license values abstract while extending the scope of spectrum property rights promotes efficiency such reforms are often deterred by equity concerns theoretically however the windfalls may be negative relaxing license restrictions may increase profits by allowing enhanced productivity yet liberalization across a class of licensees can reduce the expected profits by increasing competitiveness this article examines license value changes for regimes that decisively shift toward private property rights in radio spectrum by analyzing the average prices paid in international cellular phone license auctions during 1995 2001 this unique data set encompasses 1 365 licenses assigned by competitive bidding in 38 auctions held in 24 countries licenses awarded by regimes with more expansive spectrum property rights generated winning bids that were 61 percent lower adjusting for other factors this evidence reverses the equity argument against liberalization over the policy margin studied and is consistent with coase s view

assigning property rights to radio spectrum users why did fcc license auctions take 67 years abstract while leo herzel 1951 and ronald coase 1959 persuasively argued for auctioning licenses issued by the federal communications commission fcc not until 1993 did the u s congress grant the fcc authority to assign wireless operating permits via competitive bidding why were auctions with obvious efficiency and equity advantages so long in coming why were comparative hearings in the public interest first abandoned as assignment tools in 1981 not for auctions but for lotteries and why were radio and tv licenses pointedly excluded from auctions four factors the special interest of regulators in influencing broadcasting content the limits placed on explicit program regulation by the u s constitution the recent increase in the relative economic importance of nonbroadcast wireless services and the agency problem embedded in central planning are used to explain both the political stability of economically inefficient licensing methods and recent reforms

interrelating operational and financial performance measurements in inventory control financial supply chain management and working capital management are increasingly receiving attention as important avenues to increase profitability in supply chains by actively managing payment terms and working capital requirements managers can influence financial performance and achieve significant cost savings however measures to improve financial performance implicitly restrict and influence operational performance in our research we elaborate on the benefits of equally considering both operational and financial aspects in decision making for the physical and financial supply chain we develop a mathematical model that determines the optimal purchasing order quantity under working capital restrictions and payment delays we analyze the trade offs between the most commonly used financial and operational measurements such as service level return on investment profit margin and inventory level our results demonstrate the significance of payment delays increases decreases in the upstream downstream payment delays favor the system s operations by decreasing operational costs moreover increases in the working capital employed in the system decrease the total operational cost increase the total financial cost and lower the return on working capital investment c 2009 elsevier b v all rights reserved

an economic order quantity model for deteriorating items with partially permissible delay in payments linked to order quantity abstract to attract more sales suppliers frequently offer a permissible delay in payments if the retailer orders more than or equal to a predetermined quantity w in this paper we generalize goyal s k 1985 eoq under conditions of permissible delay in payments journal of the operational research society 36 335 338 economic order quantity eoq model with permissible delay in payment to reflect the following real world situations 1 the retailer s selling price per unit is significantly higher than unit purchase price 2 the interest rate charged by a bank is not necessarily higher than the retailer s investment return rate 3 many items such as fruits and vegetables deteriorate continuously and 4 the supplier may offer a partial permissible delay in payments even if the order quantity is less than w we then establish the proper mathematical model and derive several theoretical results to determine the optimal solution under various situations and use two approaches to solve this complex inventory problem finally a numerical example is given to illustrate the theoretical results