evolution of population resource dynamics models abstract this paper provides a comprehensive analysis of brander and taylor s 1998 model and its descendants from the following perspectives population growth substitutability innovation capital accumulation property rights and institutional designs and modeling approach this survey aims to contribute to a better understanding of population and resource dynamics models in general and facilitate further application of the model framework to relevant circumstances although often treated as exogenous in optimal growth models making population growth an endogenous function allows us to analyze broader effects of economic activities on population the issues of substitutability innovation and capital accumulation are intertwined allowing a model to address the effect of an endogenous technological change on substitutability between natural and man made capital facilitates our analyses of sustainability issues to address internalizing inter generational externalities in resource use incorporating property right changes and institutional designs to this type of model is a useful exercise but careful attention is needed for the consistency between such an arrangement and the mathematical representation of the depicted economy finally although the common criticism regarding convenient mathematical assumptions applies to the existing bt type models the use of computer simulation can relax such assumptions to better represent the intended relationships between the relevant variables

capacity allocation ordering and pricing decisions in a supply chain with demand and supply uncertainties abstract this paper studies coordinated decisions in a decentralized supply chain that consists of one original equipment manufacturer oem one manufacturer and one distributor and possesses uncertainties at both demand and supply sides these uncertainties emerge respectively from random demand the distributor faces and randomness of capacity with which the oem processes the manufacturer s outsourced quantity sharing supply and demand uncertainty information along the supply chain enables us to develop three models with different coordination efforts the oem and manufacturer coordination the manufacturer and distributor coordination and the oem manufacturer and distributor coordination and quantify the coordinated decisions in these three models our analysis of these coordination models suggests that coordinating with the oem improves the manufacturer s probability of meeting downstream demand and his expected profit yet coordinating with the manufacturer is not necessarily beneficial to the oem when downstream coordination is lacking

resource use institutions and sustainability a tale of two pacific island cultures this paper examines two pacific island cultures easter island and tikopia and the relationship between natural resource systems human made capital population growth and institutional change easter island followed a preindustrial society pattern of overshoot and collapse however tikopia evolved cultural practices leading to zero population growth and sustainable resource use using a modified lotka volterra predator prey model we find 1 investment in human made capital does not necessarily eliminate the boom and bust cycles of economic activity and population observed in many past societies and 2 institutional adaptation and resource conservation can be critical in achieving population stability

managing channel profits a channel of distribution consists of different channel members each having his own decision variables however each channel member s decisions do affect the other channel members profits and as a consequence actions a lack of coordination of these decisions can lead to undesirable consequences for example in the simple manufacturer retailer consumer channel uncoordinated and independent channel members decisions over margins result in a higher price paid by the consumer than if those decisions were coordinated in addition the ensuing suboptimal volume leads to lower profits for both the manufacturer and the retailer this paper explores the problems inherent in channel coordination we address the following questions what is the effect of channel coordination what causes a lack of coordination in the channel how difficult is it to achieve channel coordination what mechanisms exist which can achieve channel coordination what are the strengths and weaknesses of these mechanism what is the role of nonprice variables e g manufacturer advertising retailer shelf space in coordination does the lack of coordination affect normative implications from in store experimentation can quantity discounts be a coordination mechanism are some marketing practices actually disguised quantity discounts we review the literature and present a simple formulation illustrating the roots of the coordination problem we then derive the form of the quantity discount schedule that results in optimum channel profits this article was originally published in marketing science volume 2 issue 3 pages 239 272 in 1983

on modeling human behavior and institutions in simple ecological economic systems abstract the use of stylized dynamical systems models and bifurcation analysis in modeling individual and collective behavior in two traditional societies the tsembaga of new guinea and the polynesians of easter island is explored the analysis is used to isolate key aspects of individual behavior that open up the possibility of resource overexploitation and key aspects of institutions capable of preventing overexploitation an extension of the brander and taylor am econ rev 88 1998 119 138 easter island model with a more realistic model for individual behavior is presented this induces significant changes in the model dynamics which share many similarities with the tsembaga model of anderies j theor biol 192 1998 515 530 namely in both models the ability of agents to intensify the exploitation of the resource base to attempt to meet demands is a fundamentally destabilizing force the model implications for present day policy issues are explored

supply chain coordination with downstream operating costs coordination and investment to improve downstream operating efficiency abstract we endow the downstream firm in a supply chain with operating costs in addition to the traditional overage and underage costs we reanalyze lariviere and porteus s selling to a newsvendor model 2001 allowing for non linear production costs and provide comparative statics we then explore investment in reducing downstream operating costs to overcome the fact that investment is lower in a decentralized chain than in an integrated one we propose several coordination mechanisms buybacks revenue sharing and operating subsidy with a license fee

research on the dynamic linkage among the carbon emission trading energy and capital markets abstract facing the huge pressure of emission reduction china officially launched a national carbon emission trading system at the end of 2017 the power industry is an important breakthrough in the construction of china s carbon emission trading system to push the optimization of the power structure through carbon constraint is the necessary path to promote the transformation of the power industry from fossil energy to clean and low carbon energy from the perspective of power consumption this paper constructs the linkage mechanism model of china s carbon emission trading market energy market and capital market and applies the dcc mvgarch model to analyze the dynamic linkage mechanism of the three markets the results show that the price fluctuation of the yield series of products in each market has clustering characteristics and the dynamic correlation has significant time varying characteristics and persistent characteristics the dynamic conditional correlation between the carbon emission trading market and the oil market and between the carbon emission trading market and the natural gas market are basically consistent the dynamic correlation coefficient between the carbon emission trading market and the capital market is negative which is related to the unreasonable quota setting in china s carbon emission market on the basis of empirical analysis the optimal balance weight and the optimal hedging ratio of each asset are determined

competition and outsourcing with scale economies scale economies are commonplace in operations yet because of analytical challenges relatively little is known about how firms should compete in their presence this paper presents a model of competition between two firms that face scale economies i e each firm s cost per unit of demand is decreasing in demand a general framework is used which incorporates competition between two service providers with price and time sensitive demand a queuing game and competition between two retailers with fixed ordering costs and pricesensitive consumers an economic order quantity game reasonably general conditions are provided under which there exists at most one equilibrium with both firms participating in the market we demonstrate in the context of the queuing game that the lower cost firm in equilibrium may have a higher market share and a higher price an enviable situation we also allow each firm to outsource their production process to a supplier even if the supplier s technology is no better than the firms technology and the supplier is required to establish dedicated capacity so the supplier s scale can be no greater than either firm s scale we show that the firms strictly prefer to outsource we conclude that scale economies provide a strong motivation for outsourcing that has not previously been identified in the literature

an empirical typology of energy services based on a well developed market france abstract the investigation is an attempt to apply a set of consistent and official definitions of energy services es energy efficiency services ees and energy performance contracting epc on a well developed market france after defining the historical context of the french market the authors describe the types of offers that are presently made and that fall within the definition of energy services there are many classic and novel factors for the success of energy services for instance the energy services market is now partly structured by the cee scheme the french white certificates or energy certificates scheme also the grid problems lead to new services the companies active on the market are described as a result of an empirical survey of es market in france this empirical survey of es market in france includes estimates of the number of companies and of their turnover both for es and ees examples and case studies are developed as a background

discount pricing decisions in distribution channels with price sensitive demand abstract in this paper we evaluate the effectiveness of quantity discounts and volume discounts as coordination mechanisms in distribution channels with demand that is price sensitive we consider a single vendor single retailer distribution channel demand for the product arises only at the retailer the demand faced by the retailer is assumed to be deterministic but price elastic the retailer in turn buys the product from the vendor the vendor and the retailer act independently and rationally each maximizing their own respective profit the equilibrium point that specifies the vendor s and buyer s inventory and pricing policy is determined by the solution to a stackelberg game we consider the cases when quantity discount and volume discount respectively are offered we develop methods to determine the optimal discount policy for these cases we then consider the case where both volume and quantity discounts are offered simultaneously and develop a method to determine the optimal simultaneous discount offer the relative performance of the alternative discount schemes is then evaluated through a numerical study the results of the study demonstrate that the effectiveness of volume discount as a coordination mechanism is higher when the sensitivity of demand to price changes is higher the effectiveness of quantity discount on the other hand is higher with lower price sensitivity of demand finally the results also demonstrate that perfect coordination is achieved when volume and quantity discounts are offered simultaneously

energy efficiency services for residential buildings market situation and existing potentials in the european union although a substantial economic energy saving potential exists in the residential sector of the european union the energy efficiency service ees market is much less developed in this market segment than in other demand sectors e g the industry or the public service sector this paper presents an analysis of the current situation and existing potentials for future expansion a specific analysis methodology has been developed and applied by a research consortium in 18 eu countries this methodology has mostly built upon an extensive review of the existing literature and on interviews of a large number of acknowledged experts its application has allowed identifying encouraging development trends in specific market segments where the possibility of aggregating the ees demand or of exploiting good relationships with customers have created interesting investment opportunities these trends have been observed in particular in germany denmark france flanders be hungary romania and uk the assessment performed has also allowed discussing a series of strategies and policy measures that can be adopted to overcome existing barriers to market development the general conclusion drawn in the paper is that energy efficiency policies supporting ees markets in the residential sector are highly needed although eu policies have typically a limited direct impact they can increase trust into eess and ees providers at the national level a stronger collaboration of governments or local administrations with banks to finance eess is still very necessary in many eu countries

energy supplier obligations and white certificate schemes comparative analysis of experiences in the european union abstract a number of member states of the european union eu have introduced market based policy portfolios based on quantified energy savings obligations on energy distributors or suppliers possibly coupled with certification of project based energy savings via white certificates and the option to trade the certificates or obligations the paper provides an up to date review and analysis of results to date of white certificate schemes in the eu in the eu supplier obligations and white certificate schemes have delivered larger savings than originally expected with obliged companies exceeding targets and in some cases at cost below what policy makers have anticipated supplier obligations foster the uptake of standardised energy efficiency actions often targeting smaller energy users residential sector lowering the transaction costs and contributing to market transformation the role of certificate trading is more ambiguous trading can bring benefits where the target is set sufficiently high with respect to the energy saving potential in the sectors covered theoretically trading may be better suited for broader systems with comprehensive coverage but even in smaller schemes trading may reduce the transaction costs of compliance for obliged actors without sufficient expertise on end use energy efficiency yet trading increases the administrative cost ratio of energy saving obligations

double marginalization and coordination in the supply chain with uncertain supply abstract this paper explores a generalized supply chain model subject to supply uncertainty after the supplier chooses the production input level decentralized systems under wholesale price contracts are investigated with double marginalization effects shown to lead to supply insufficiencies in the cases of both deterministic and random demands we then design coordination contracts for each case and find that an accept all type of contract is required to coordinate the supply chain with random demand which is a much more complicated situation than that with deterministic demand examples are provided to illustrate the application of our findings to specific industrial domains moreover our coordination mechanisms are shown to be applicable to the multi supplier situation which fills the research gap on assembly system coordination with random yield and random demand under a voluntary compliance regime

coupled societies are more robust against collapse a hypothetical look at easter island inspired by the challenges of environmental change and the resource limitations experienced by modern society recent decades have seen an increased interest in understanding the collapse of past societies modelling efforts so far have focused on single isolated societies while multi patch dynamical models representing networks of coupled socio environmental systems have received limited attention we propose a model of societal evolution that describes the dynamics of a population that harvests renewable resources and manufactures products that have positive effects on population growth collapse is driven by a critical transition that occurs when the rate of natural resource extraction passes beyond a certain point for which we present numerical and analytical results applying the model to easter island gives a good fit to the archaeological record subsequently we investigate what effects emerge from the movement of people goods and resources between two societies that share the characteristics of easter island we analyse how diffusive coupling and wealth driven coupling change the population levels and their distribution across the two societies compared to non interacting societies we find that the region of parameter space in which societies can stably survive in the long term is significantly enlarged when coupling occurs in both social and environmental variables

analysis of an inventory system under supply uncertainty in this paper we analyze a periodic review single item inventory model under supply uncertainty the objective is to minimize expected holding and backorder costs over a finite planning horizon under the supply constraints the uncertainty in supply is modeled using a three point probability mass function the supply is either completely available partially available or the supply is unavailable machine breakdowns shortages in the capacity of the supplier strikes etc are possible causes of uncertainty in supply we demonstrate various properties of the expected cost function and show the optimality of order up to type policies using a stochastic dynamic programming formulation under the assumption of a bernoulli type supply process in which the supply is either completely available or unavailable and when the demand is deterministic and dynamic we provide a newsboy like formula which explicitly characterizes the optimal order up to levels an algorithm is given that computes the optimal inventory levels over the planning horizon extensions and computational analysis are presented for the case where the partial supply availability has positive probability of occurrence

modeling quantity discounts under general price sensitive demand functions optimal policies and relationships this paper presents models for determining optimal all unit and incremental quantity discount policies and investigates the effect of quantity discounts on increasing demand and ensuring pareto efficient transactions under general price sensitive demand functions the paper develops optimal quantity discount policies investigates their interrelationships and their benefits to both the supplier and the buyer and gains managerial insights for the scenarios of maximizing the supplier s profit and the joint profit we develop simple and efficient solution approaches for determining the all unit and the incremental optimal decision policies for general price sensitive demand functions we have three main findings first with price sensitive demand there are two incentives in offering quantity discounts increasing demand and ensuring pareto efficient transactions in most cases increasing demand dominates in justifying the offering of quantity discounts second using a single lot size associated with all efficient transactions as with the constant demand case does not hold with the price sensitive demand case third the optimal all unit quantity discount policy is equivalent to the optimal incremental quantity discount policy in benefiting both the supplier and the buyer

sub supply chain coordination in a three layer chain under demand uncertainty and random yield in production abstract one of the major objectives of modern supply chain management is to deal with the growing decentralization among the involved entities and hence minimizing the double marginalization effect inside the chain especially when the end customers demand is not deterministic to address this a three layer supply chain with one raw material supplier one manufacturer and one retailer is developed and studied in this paper effects of both supply chain coordination as well as sub supply chain coordination are examined optimal order and production quantities are obtained for the centralized system which depicts the scenario under coordination optimal order quantities and expected profits of the individual channel actors are maximized locally in the decentralized system under commonly used price only contract semi integrated models are also studied under price only contract the optimal strategies under different power structures are compared and the effects of the channel parameters on the optimal strategies are also examined numerical example is given to illustrate the developed model

joint pricing and inventory policies for make to stock products with deterministic price sensitive demand abstract in this paper we focus on a firm selling a single make to stock product to price sensitive end customers we develop an integrated operations marketing model that can help determine the relevant profit maximizing decision variable values for two pricing policies that the firm might follow price as a decision variable which is advocated by academicians and mark up pricing used by most practitioners we first consider an eoq based model with price and order quantity as independent decision variables we then develop an analogous model where price is a mark up over operating costs per unit and order quantity becomes the sole decision variable we are able to ascertain the optimal decision variable values for each model for log linear and linear demand functions we prove that for such profit maximizing models the optimal batch size is not necessarily monotone increasing in set up cost interestingly our numerical analytical evidence suggests that from a profit perspective it is better for managers to be aggressive on price rather than reducing price too much especially for highly price sensitive and non linear demand moreover we establish that in general the profit penalty for not including inventory costs in determining the optimal batch size or ignoring the batch size optimization issue in a mark up price model is not significant only when the set up cost is quite high and or the firm faces non linear demand from highly price sensitive end consumers does it become crucial for managers to determine the exact optimal batch size and base the mark up price on the entire unit operating cost not only the unit variable production cost

coordinated decisions for substitutable products in a common retailer supply chain abstract this paper studies coordination mechanisms in a supply chain which consists of two suppliers with capacity uncertainties selling differential yet substitutable products through a common retailer who faces price sensitive random demand of these two products we develop in a noncompetitive setting three coordination models revenue sharing return policy and combination of revenue sharing and return policy and contrast them with a basic and uncoordinated model we are able to establish the ordinal relationship among the retailer s ordering and pricing decisions and analytically compare the performances between certain models when two suppliers are identical we find that the retailer s ordering and pricing decisions in the model with return policy in the case of identical suppliers are independent of demand or supply uncertainty our numerical results reveal that the performances of coordination models in the case of nonidentical suppliers resemble those in the case of identical suppliers we find that the retailer will place a larger order quantity in models where her average cost per unit sold is smaller we also find that product substitutability and uncertainties have different effects on chain performances

an econometric analysis of the drivers for residential heating consumption in the uk and germany abstract affecting millions of europeans energy poverty is increasingly high on the political agenda this paper compares space and water heating demand at household level in germany and in the united kingdom uk between 1991 and 2015 the elasticities of consumption of space and water heating with respect to price income and heating degree days hdd are examined using non parametric models domestic heating consumption is highly elastic with hdd in both countries and hdd elasticities are found to be higher in the uk from a certain income threshold heating demand decreases as income increases in german households whereas demand rises with higher incomes in the uk high price elasticities indicate that uk households are very responsive to energy conservation measures therefore implying that a pricing policy will effectively reduce heating consumption however in germany the impact of pricing policies is unclear thus the most effective policy measure to decrease domestic heating consumption in germany in the long run should be one which targets improvements of building envelope performance levels

renewable resources property rights regimes and endogenous growth abstract we extend brander and taylor s brander j a taylor m s 1998 the simple economics of easter island a ricardo malthus model of renewable resource use am econ rev 88 119 138 model of feast and famine cycles on easter island using galor and weil s gailor o weil d n 2000 population technology and growth from malthusian stagnation to the demographic transition and beyond am econ rev 90 806 28 model of endogenous technological advance where technological change is related to the population we note that different property rights regimes will influence the relative direction of technological advance whether that advance is in harvesting technologies or in technologies that influence the growth rate of some renewable biological resource property rights regimes that favor biological growth rates over harvest rates tend to dampen feast famine cycles while those that favor harvest efficiency worsen such cycles

measuring the progress towards a resource efficient european union under the europe 2020 strategy abstract resource efficiency is an essential priority of the europe 2020 strategy which under the flagship initiative for a resource efficient europe calls for a shift towards a resource efficient economy in this context indicators and composite indexes could be useful in order to evaluate the progress of the european union towards the objectives of the roadmap to a resource efficient europe this paper benchmarks the 28 european members based on a composite index namely the resource efficiency capacity index the index is based on the calculations of 29 indicators which are grouped in three dimensions the first dimension benchmarks eu 28 members according to the promotion of waste recycling to the support of research and innovation in resource efficiency and to the implementation of environmental taxation the second dimension benchmarks eu members according to energy efficiency in residential buildings and the third dimension according to the development of more sustainable transport modes the three dimensions are aggregated for a final ranking the results indicate that denmark received the highest ranking with a composite index value of 3 35 followed by sweden 3 22 and finland 3 13 in 2013 the establishment of more effective policies is necessary in the member states with the lowest scores in the resource efficiency capacity index slovakia 1 8 malta 1 92 and poland 1 93 although the european union has made considerable progress in this issue in the last decade many actions should still be faced to increase resource efficiency to inform more about the concept of life cycle thinking to increase waste recycling to make more attractive the system of public passenger transport or to increase the energy efficiency of residential buildings among others

price delivery time guarantees and capacity selection this paper studies the impact of using delivery time guarantees as a competitive strategy in service industries where demands are sensitive to both price and delivery time we assume that delivery reliability is crucial and investment in capacity expansion is plausible in order to maintain a high probability of delivering the time guarantee a mathematical framework is proposed to understand the interrelations among pricing delivery time guarantee and capacity expansion decisions specifically an optimization model is developed to determine the joint optimal selection of these three important decision variables with an objective of maximizing the average net profit we characterize the optimal decisions and study their qualitative behaviors as various parameters change we further present a numerical example to illustrate how the results of our model can be used to provide useful managerial insights for selecting the best competing strategies for firms with different operating characteristics our model and results are also applicable to a make to order manufacturing environment

the co evolutionary relationship between energy service companies and the uk energy system implications for a low carbon transition abstract the energy service company esco business model is designed to reward businesses by satisfying consumers energy needs at less cost and with fewer carbon emissions via energy demand management and or sustainable supply measures in contrast the revenue of the incumbent energy utility company euco model is coupled with the sale of units of energy which are predominantly sourced from fossil fuels the latter is currently dominant in the uk this paper addresses two questions first why has the esco model traditionally been confined to niche applications second what role is the esco model likely to play in the transition to a low carbon uk energy system to answer these the paper examines the core characteristics of the esco model relative to the euco model the paper then examines how escos have co evolved with the various dimensions of the energy system i e ecosystems institutions user practices technologies and business models to provide insight into how escos might help to shape the future uk energy system we suggest that institutional and technological changes within the uk energy system could result in a more favourable selection environment for escos consequently enabling the esco model to proliferate at the expense of the euco model

energy performance of dwelling stock in iceland system dynamics approach abstract despite the significant energy use in dwellings buildings have the highest energy savings potential among all sectors one of the main analytical challenges is how to capture the impact from inertia driven by the current dwelling stock thus a dwelling stock model was established to study the impacts of physical processes e g aging as well as the effect of social processes e g household energy conservation behaviors on energy demand for space heating in the icelandic dwelling stock the model is initialized in the year 2000 and then calibrated with datasets on the icelandic dwelling stock and hot water consumption for residential space heating analysis of the base scenario confirms that the improvement in the average energy intensity of total dwelling stock with regular turnover of the dwelling stock is insignificant and gradual which relates to the inertia of the existing stock the comparison of the results from two policy scenarios with the base case illustrates that the aggressive demolition is more effective compared to the aggressive construction in reducing the total energy demand for space heating the results of this analysis can support policy makers by providing insights regarding the potential impact of building energy efficiency policies ensuring an effective policy package

channel coordination and quantity discounts this paper presents a model for analyzing the impact of joint decision policies on channel coordination in a system consisting of a supplier and a group of homogeneous buyers the joint decision policy characterized by the unit selling price and the order quantity is coordinated through quantity discounts and franchise fees both the annual demand rate and the operating cost including the purchase ordering and inventory holding costs depend on the joint decision policy employed this paper contributes by integrating work addressing quantity discounts on inventory and ordering policies and work focusing on the control mechanism provided by quantity discounts in channel coordination it is shown that the optimal all unit quantity discount policy is equivalent to the optimal incremental quantity discount policy in achieving channel coordination furthermore it is shown that quantity discounts alone are not sufficient to guarantee joint profit maximization the analyses of the general models are illustrated by specific analytical results obtained for a given demand function