management of social issues in supply chains a literature review exploring social issues actions and performance outcomes the social dimension of sustainable development and its impact on supply chains have so far received less attention than the environmental dimension the aim of the research is to explore the intersection between social issues corporate social responsibility csr actions and performance outcomes a structured literature review of social issues in supply chains is presented analysing the research published so far in peer reviewed publications linking csr and supply chain management allows the exploration of strategies and performance outcomes with a focus on social issues the corresponding responsible supply chain actions adopted by firms to address these issues are grouped into communication compliance and supplier development strategies social and economic as well as buyer and supplier performance are identified as the key outcomes but the interactions among these constructs would require further research this paper contributes to the understanding of managing social issues in supply chains by linking social issues responsible supply chain actions and performance outcomes the paper consolidates related research by offering an overarching conceptual framework and points to future research directions and simultaneously provides insights into the management of social issues in supply chains

co2 emissions of international freight transport and offshoring measurement and allocation abstract the growing offshoring process is the result of the fragmentation of production processes and the creation of global supply chains this process has increased final and intermediate imports but also the distance that goods travel in different stages until they reach the final consumer as well as the requirements of transport per unit of output and the volume of co 2 emissions generated in transporting them nowadays there is no generally accepted criterion for international transport pollution allocation no single country has the responsibility for emissions of international bunkers provided by ipcc in this paper we propose a new methodology for quantifying by sector the impact of international freight transport on total pollution and assigning responsibility to consumers this methodology considers the distance and the means of transport as key elements and uses input output methodology we apply this to the spanish economy combining data from input output tables import data and co 2 emission data the results show that the proportion of total co 2 emissions accounted for by emissions from international freight transportation allocated via the consumer criterion increase up to 4 16 between 1995 and 2000 as expected the industries where this offshoring process is more intense show the greatest increases in carbon emissions related to international transport these emissions are significantly higher than emissions embodied in domestic inputs in some of those industries where international fragmentation of production is relevant and increasing

optimal insurance in incomplete markets this paper examines the theory of optimal insurance purchasing in the presence of uninsurable background risk existing theorems concerning the optimal level of insurance and the optimal form of an insurance contract are shown to hold only under restricted market and risk assumptions in particular conditions sufficient for the optimality of full coverage or sufficient for the optimality of deductible policies depend on the correlation between insurable and uninsurable risks these results may provide a partial explanation why existing theory is often contradicted by observable behavior

the sustainable supply chain network competition with environmental tax policies abstract this paper captures different environmental tax policies in a multi tiered supply chain network competition context we derive the governing equilibrium conditions for the noncooperative game theory models for each firm and provide the equivalent variational inequality formulations the numerical examples investigate the impacts of emission tax policies and product differentiation on the competing firms and compare the effects of different environmental policies flat emission tax rates progressive emission taxes and the government command and control regulations with emission standards on equilibrium product demands prices total emissions and overall profits the computational results indicate that the implementation of environmental tax policies along with an increase in consumers environmental concerns can not only motivate the firms to perform sustainable operations but also reduce the total carbon footprint furthermore the low cost progressive emission tax policies can be as effective as the high flat emission tax rate in terms of reduction in carbon footprint therefore the model developed in this paper can be used by the policymakers and the firms to evaluate the effects of different environmental tax policies in a supply chain competition context

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

trade and the greenhouse gas emissions from international freight transport we collect extensive data on worldwide trade by transportation mode and use this to provide detailed comparisons of the greenhouse gas emissions associated with output versus international transportation of traded goods international transport is responsible for 33 percent of world wide trade related emissions and over 75 percent of emissions for major manufacturing categories including transport dramatically changes the ranking of countries by emissions per dollar of trade we systematically investigate whether trade inclusive of transport can lower emissions in one quarter of cases the difference in output emissions is more than enough to compensate for the emissions cost of transport finally we examine how likely patterns of global trade growth will affect modal use and emissions full liberalization of tariffs and gdp growth concentrated in china and india lead to transport emissions growing much faster than the value of trade due to trade shifting toward distant trading partners

coordinating a three level supply chain with learning based continuous improvement abstract learning curve theory has been widely used as a managerial tool to describe and model product and process improvement this paper investigates a three level supply chain supplier manufacturer retailer where the manufacturing operations undergo a learning based continuous improvement process improvements in the manufacturer s operation are characterized by enhanced capacity utilization reductions in set ups times and improved product quality through the elimination of rework as a result of these continuous improvements the manufacturer can justify a production policy that is based on more frequent smaller lot size production for this production policy to be practical and not sub optimal to the supply chain the manufacturer must integrate its lot sizing models with the replenishment policies of its upstream raw material suppliers and the demand requirements of its downstream customers retailers mathematical models that achieve chain wide lot sizing integration are developed and solution procedures for the models are illustrated by numerical examples the results demonstrate that learning based improvements in set up time and rework allow retailers to order in progressively smaller lot sizes as the manufacturer offers larger discounts and profits and that the entire supply chain benefits from implementing learning based continuous quality improvements the results also demonstrate that forgetting effects lead to increases in supply chain costs

design of sustainable supply chains under the emission trading scheme increase in environmental concerns together with legislations are forcing industries to take a fresh look at the impact of their supply chain operations on the environment this paper introduces a mixed integer linear programming based framework for sustainable supply chain design that considers life cycle assessment lca principles in addition to the traditional material balance constraints at each node in the supply chain indeed the framework distinguishes between solid and liquid wastes as well as gaseous emissions due to various production processes and transportation systems the framework is used to evaluate the tradeoffs between economic and environmental objectives under various cost and operating strategies in the aluminum industry the results suggest that current legislation and emission trading schemes ets must be strengthened and harmonized at the global level in order to drive a meaningful environmental strategy moreover the model demonstrates that efficient carbon management strategies will help decision makers to achieve sustainability objectives in a cost effective manner

the single vendor single buyer integrated production inventory model with a generalised policy abstract this note considers a more general type of policy for the single vendor single buyer integrated production inventory model than has hitherto been presented based on successive shipments to the buyer within a single production batch increasing by a fixed factor

is there really a green paradox abstract in the absence of a co2 tax the anticipation of a cheaper renewable backstop increases current emissions of co2 since the date at which renewables are phased in is brought forward and more generally future emissions of co2 will decrease the effect on global warming is unclear green welfare falls if the backstop is relatively expensive and full exhaustion of fossil fuels is optimal but may increase if the backstop is sufficiently cheap relative to the cost of extracting the last drop of fossil fuels plus marginal global warming damages as then it is attractive to leave more fossil fuels unexploited and thus limit co2 emissions we establish these results by analyzing depletion of non renewable fossil fuels followed by a switch to a clean renewable backstop paying attention to timing of the switch and the amount of fossil fuels remaining unexploited we also discuss the potential for limit pricing when the non renewable resource is owned by a monopolist finally we show that if backstops are already used and more backstops become economically viable as the price of fossil fuels rises a lower cost of the backstop will either postpone fossil fuel exhaustion or leave more fossil fuel in situ thus boosting green welfare however if a market economy does not internalize global warming externalities and renewables have not kicked in yet full exhaustion of fossil fuel will occur in finite time and a backstop subsidy always curbs green welfare

coordination mechanisms of supply chain systems supply chain management scm has become an important management paradigm as supply chain members are often separate and independent economic entities a key issue in scm is to develop mechanisms that can align their objectives and coordinate their activities so as to optimize system performance in this paper we provide a review of coordination mechanisms of supply chain systems in a framework that is based on supply chain decision structure and nature of demand this framework highlights the behavioral aspects and information need in the coordination of a supply chain the identification of these issues points out several directions of future research in this area

delay in payments a strategy to reduce carbon emissions from supply chains abstract the purpose of this paper is to study the effects of various scenarios of delay in payments a form of trade credit by a buyer after receiving items while including various costs such as fuel cost the costs of carbon emissions from manufacturing and transportation activities order cost and setup cost in a two echelon coordinated supply chain the model developed optimizes the environmental and economic performance of a supply chain the study presents a comparison of different scenarios through numerical examples and sensitivity analyses the main contribution of this paper is the joint consideration of delays in payments and the costs of transportation cost and carbon emissions the model has been tested with numerical examples and sensitivity analyses the findings showed that adopting delays in payments improves both environmental and economic performance of a supply chain the analyses also showed that optimizing one of the parameters from the production rate the length of delay in payments or the lot size provides the optimal solution for carbon emissions and the system cost of a supply chain this flexibility makes the model easy to use by practitioners

moral hazard and optimal commodity taxation abstract this paper demonstrates that in an economy with moral hazard and more than one commodity competitive equilibrium is not constrained efficient to correct the market failure differential commodity taxation is necessary a general optimal tax formula is derived and special cases of is discussed

medical insurance technological change and welfare concerns have been expressed about the welfare effects of expensive innovations in medical care financed largely through medical insurance this paper develops a model which considers such issues it is shown that even if insurance is purchased optimally subject to a plausible constraint on the form of the contract innovations may be adopted that have the effect of reducing expected welfare the question of how the benefits of medical innovations ought to be measured in the presence of insurance is also explored

the carbon constrained eoq model with carbon emission dependent demand abstract currently companies are looking for solutions to reduce carbon emissions associated with their operations operational adjustments such as modifications in batch sizes or order quantities have proven to be an effective way to decrease emissions in this paper a novel model is proposed that takes into account the link between an inventory policy eoq total carbon emissions and both price and environmental dependent demands in the case of an exogenous price two optimal quantities are determined which maximize a retailer s profit and which minimize carbon emissions conditions that allow a company to maximize profit while minimizing emissions and mechanisms that allow a firm to maximize its profit and to decrease its carbon emissions are determined in the case of an endogenous price some empirical results are also discussed when a firm optimizes its profit through both its selling price and its order quantity some experiments match empirical observations on the one hand an environmental strategy is more significant for cheaper and green labeled products on the other hand a public mechanism such as a carbon tax will decrease total and marginal emissions

uncertainty and the demand for medical care abstract this paper provides an analysis of the effects of uncertainty on the demand for medical care using a simplified version of grossman s human capital model of the demand for health two types of uncertainty are analysed the uncertainty surrounding the incidence of illness and the uncertainty surrounding the effectiveness of medical care in the first the consumer s basic level of health is assumed to be a random variable in the second the effectiveness of medical care is assumed to be random comparative static results are reported indicating the effects on the demand for medical care of both increases in the means of these distributions and mean preserving spreads of the distributions

including sustainability criteria into inventory models research on sustainability performance has considerably enriched operations management literature in recent years however work with quantitative models is still scarce this paper contributes by revisiting classical inventory methods taking sustainability concerns into account we believe that reducing all aspects of sustainable development to a single objective is not desirable we thus reformulate the classical economic order quantity model as a multiobjective problem we refer to this model as the sustainable order quantity model then a multi echelon extension of the sustainable order quantity model is studied for both models the set of efficient solutions pareto optimal solutions is analytically characterized these results are used to provide some insights about the effectiveness of different regulatory policies to control carbon emissions we also use an interactive procedure that allows the decision maker to quickly identify the best option among these solutions the proposed interactive procedure is a new combination of multi criteria decision analysis techniques

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

managing carbon footprints in inventory management abstract there is a broad consensus that mankind must reduce carbon emissions to mitigate global warming it is generally accepted that carbon emission trading is one of the most effective market based mechanisms to curb the amount of carbon emissions this paper investigates how firms manage carbon footprints in inventory management under the carbon emission trading mechanism we derive the optimal order quantity and analytically and numerically examine the impacts of carbon trade carbon price and carbon cap on order decisions carbon emissions and total cost we make interesting observations from the numerical examples and provide managerial insights from the analytical results

optimal health insurance for multiple goods and time periods we examine the efficiency based arguments for second best optimal health insurance with multiple treatment goods and multiple time periods correlated shocks across health care goods and over time interact with complementarity and substitutability to affect optimal cost sharing health care goods that are substitutes or have positively correlated demand shocks should have lower optimal patient cost sharing positive serial correlations of demand shocks and uncompensated losses that are positively correlated with covered health services also reduce optimal cost sharing our results rationalize covering pharmaceuticals and outpatient spending more fully than is implied by static one good or one period models

altruism the samaritan s dilemma and government transfer policy this paper shows that altruism provides an efficiency rationale for public provision of insurance to the poor the framework is one in which there are rich altruists and risk averse poor who face some possibility of loss the government represents the rich and makes transfers on their behalf with unconditional transfers the poor may forgo insurance and rely on private charity to bail them out in the event of loss this reliance on private charity has adverse efficiency effects these may be avoided if the government makes in kind transfers of insurance copyright 1995 by american economic association

optimal procurement policies under price dependent demand abstract we study a periodic review inventory model where in addition to the procurement quantity price is also a decision variable we develop a model where demand in each period is a random variable having a price and possibly period dependent probability distribution with the expected demand decreasing in price the model includes price limits and fixed ordering costs in addition to unit procurement holding and shortage costs we study the optimal policies which jointly maximize the discounted expected profit over a finite planning horizon we characterize the form of the optimal procurement policy under a general price demand relationship and give a sufficient condition for it to be s n s n type we also discuss some special cases and extensions to the basic model including the infinite horizon problem

environmentally responsible inventory models non classical models for a non classical era abstract mathematical models of inventory typically include the three inventory associated costs of surplus shortage and ordering these classic inventory models are then analysed so as to choose inventory parameters that usually minimise the total cost of operating the inventory system being investigated unfortunately classic inventory models do not provide a meaningful basis for analysing many real and increasingly important practical inventory problems and situations it is therefore not surprising that over recent years several authors have discussed these issues in broad terms and suggested that a new paradigm needs to be developed this paper develops some specific aspects of this discussion in particular the paper identifies a range of inventory problems that are not covered appropriately by traditional inventory analysis one of these is to design responsible inventory systems i e systems that reflect the needs of the environment the paper then examines the importance of inventory planning to the environment in greater detail for example packaging is important not only because of its costs and the protection that it provides to the inventory items but also because of its eventual effects on the environment in terms of the use of resources and potential landfill for similar reasons waste which can result from poor inventory management is highly important the location of stores is important because location affects transport costs thus the influence of the secondary aspects of most inventory models packaging waste and location are important but even more important are the inter relations with the total system in particular the location of the manufacturing plants and the effect that inventory planning has on the logistics chain potentially have considerable environmental implications inventory is part of a wider system however until the cost charged for an activity reflects the true environmental cost of that activity it is likely that decisions will be made on the basis of erroneous data in that situation we are faced with either determining the environmental cost of specific actions or to use environmental costs that are somewhat contrived in which case it may be more sensible to use very different performance measures and models the paper discusses these ideas and ways in which inventory policies may reassure us with our environmental concerns

does service level spending show evidence of selection across health plan types we provide an explanation for the widespread finding that capitated managed care plans attract comparatively healthy low cost enrollees relative to traditional unmanaged plans using disaggregated commercial insurance claims from the thomson reuters marketscan database we show that managed care plans spend proportionally less on those types of services that are predicted to be more profitable to ration tightly using a selection index developed by ellis and mcguire that captures the derivative of profits with respect to reduced spending on disaggregated services conventional diagnosis based risk adjusted premiums reduce selection incentives by about 50 relative to premiums that are not risk adjusted

optimal reimbursement health insurance and the theory of ramsey taxation this paper explores the trade off between risk sharing and the incentives to consume increased medical care inherent in reimbursement insurance the results for the theory of reimbursement insurance are compared with those on ramsey taxation it is shown that there is a close formal analogy and interpretations are given

the joint economic lot size problem a review abstract this article reviews lot size models which focus on coordinated inventory replenishment decisions between buyer and vendor and their impact on the performance of the supply chain these so called joint economic lot size jels models determine order production and shipment quantities from the perspective of the supply chain with the objective of minimizing total system costs this paper first describes the problem studied introduces the methodology of the review and presents a descriptive analysis of the selected papers subsequently papers are categorized and analyzed with respect to their contribution to the coordination of different echelons in the supply chain finally the review highlights gaps in the existing literature and suggests interesting areas for future research

health insurance the tradeoff between risk pooling and moral hazard choosing optimal health insurance coverage involves a trade off between the gain from risk reduction and the deadweight loss from moral hazard this paper examines this trade off empirically by estimating both the demand for health insurance and the demand for health services it relies on data from a randomized controlled trial of cost sharing s effects on the use of health services and on the health status for a general non elderly population

adverse selection with endogenous information in insurance markets abstract models of adverse selection assume that risk type is known to the consumer but not to the insurer many analyses suggest that information has zero social value and negative prior value why then would consumers become informed what is the incentive to gather information and why does adverse selection arise we show that the private value of information is non negative only if insurers cannot observe consumers information status or if consumers can conceal their informational status we examine the existence and characterization of equilibria under different configurations of information costs and benefits finally we examine some welfare implications of the endogenous information model for public policy regarding genetic testing and for state regulations concerning hiv testing