nonrenewable resource scarcity nonrenewable resource theory often is summarized by hotelling s rule this paper reviews theoretical extensions and empirical investigations of resource extraction models observed data are often inconsistent with the hotelling rule suggesting that other characteristics of nonrenewable resource supply including exploration heterogeneous ore quality technological progress and capital investment are important determinants of the dynamic behavior of resource prices given the persistent recurrence of concern about nonrenewable resource scarcity measures of nonrenewable resource scarcity and the empirical evidence for the time trends of those measures are reviewed finally the implications of nonrenewable resource scarcity for economic growth are examined

a nonequilibrium analysis of unanimity rule majority rule and pareto i introduction voting theory is important for understanding economics as well as politics international organizations vote on trade regulations legislatures vote on minimum wage and governments vote on the provision of public goods voting also affects industrial organization for instance limited partnerships may vote on the allocation of resources to various units and shareholders may vote on investment decisions carrera and richmond 1988 what voting rule best achieves pareto optimal outcomes in such cases in the absence of transactions costs it is widely believed that unanimity rule is the best voting rule for promoting pareto efficiency berggren 1996 buchanan and tullock 1962 mueller 2003 buchanan 1967 writes it is evident that unanimous consent is the political counterpart of the pareto criterion for optimality p 285 traditionally viewed unanimity rule guarantees more efficient outcomes than majority rule because unanimity rule only passes proposals that make everyone better off other voting rules like majority rule can pass proposals that make some individuals worse off one of the assumptions that is either explicit or implicit in the these studies is the assumption of rational proposals we define a proposal as rational if it helps maximize the proposer s utility at the end of the game in our analysis proposals are not rational instead they are generated either randomly or sincerely in a single dimensional voting model and evaluated by the pareto criterion or pareto optimality this produces two striking results with regard to pareto optimality first if proposal generation is random then majority rule is usually more likely to select a pareto optimal outcome than unanimity rule second if individuals propose their ideal points then majority rule always selects pareto optimal outcomes at least as well as unanimity rule considering all possible proposals as done in our random generation models has a long tradition in social choice literature arrow 1951 caplin and nalebuff 1988 niemi and weisberg 1968 riker 1982 sen 1979 it also has the advantage of modeling certain types of incomplete information modeling votes where bills are introduced for reasons other than making them pass see stewart 2001 pp 338 41 modeling exogenously generated proposals and for allowing mistakes by the proposer such foundational work should be of interest to those who relate unanimity rule to pareto principles in the study of public goods cornes and sandler 1996 lindahl 1967 political parties aldrich 1995 and legislative institutions colomer 2001 niou and ordeshook 1985 tsebelis 2002 to name a few ii previous studies perhaps the first in depth study of the relationship between unanimity rule and a pareto principle was buchanan and tullock s calculus of consent 1962 buchanan and tullock argued that if decision making costs were negligible unanimity rule would always be the most desirable k majority rule simply because it preserved the pareto principle p 88 although the exact pareto principle they had in mind is not entirely clear it seems that buchanan and tullock were arguing for the criteria of accepting a change from the status quo only if it lead to a pareto improvement otherwise the status quo should be preferred pp 92 93 sen 1979 p 25 1 mueller 2003 pp 138 and 140 41 further compared unanimity rule to majority rule and concluded that unanimity rule typically performs better in terms of the pareto criterion to illustrate his reasoning mueller describes a community voting on both the purchase of a new firehouse and the taxes needed to pay for it in a single bill if the decision was made under unanimity rule the distribution of taxes would be redefined until the firehouse benefited all otherwise the bill would not pass if the decision was made under majority rule a majority might distribute the taxes on a minority such that members of the majority would be net gainers and members of the minority would be net losers

multi resource investment strategies operational hedging under demand uncertainty abstract consider a firm that markets multiple products each manufactured using several resources representing various types of capital and labor and a linear production technology the firm faces uncertain product demand and has the option to dynamically readjust its resource investment levels thereby changing the capacities of its linear manufacturing process the cost to adjust a resource level either up or down is assumed to be linear the model developed here explicitly incorporates both capacity investment decisions and production decisions and is general enough to include reversible and irreversible investment the product demand vectors for successive periods are assumed to be independent and identically distributed the optimal investment strategy is determined with a multi dimensional newsvendor model using demand distributions a technology matrix prices product contribution margins and marginal investment costs our analysis highlights an important conceptual distinction between deterministic and stochastic environments the optimal investment strategy in our stochastic model typically involves some degree of capacity imbalance which can never be optimal when demand is known

the unanimous voting rule is not the political equivalent to market exchange the unanimous voting rule is often viewed as analogous to voluntary market ex change this paper demonstrates that when third party pecuniary effects exist this analogy breaks down because unlike markets unanimous voting requires compensation for these ef fects thus efficient market outcomes typically will be rejected by the unanimous voting rule even when transactions costs are low enough to make compensation feasible the political outcome under unanimity will differ from the market outcome the distributional effects of unanimity provide the incentive for people to substitute rent seeking behavior for productive activity and reduce the incentive for productive change providing additional reasons why a less than unanimous voting rule may be optimal when resources are to be allocated politically

the bullwhip effect in supply chains an overestimated problem abstract a phenomenon that is now well known as the bullwhip effect suggests that the variability of orders increases as they move up the supply chain from retailers to wholesalers to manufacturers to suppliers in this paper we will focus mainly on measuring the bullwhip effect existing approaches that aim at quantifying the bullwhip effect neglect the network structure of supply chains by only assuming a simple two stage supply chain consisting of a single retailer and a single manufacturer some of the relevant risk pooling effects associated with the network structure of supply chains are disregarded risk pooling effects arise when the orders which a retailer receives from its customers are statistically correlated with a coefficient of correlation less than one when analyzing the bullwhip effect in supply chains however the influence of risk pooling has to be considered the fact that these influences have not yet been analyzed motivates the research presented in this paper we will show that the bullwhip effect is overestimated if just a simple supply chain is assumed and risk pooling effects are present

providing a measure for bullwhip effect in a two product supply chain with exponential smoothing forecasts abstract in this paper a two product and two echelon supply chain is considered in order to quantify the bullwhip effect demands of the products are correlated and are represented by a first order vector autoregressive model retailer uses order up to ordering policy for replenishment of stocks and utilizes exponential smoothing forecast method to predict demand in lead time period according to the mentioned assumptions an equation is derived for bullwhip effect measurement and then a numerical example is presented for a better perception of the bullwhip effect behavior when the parameters change a comparison of the bullwhip effect measure has been done when two main forecasting methods i e exponential smoothing and moving average are used and empirical results are provided at last a cost analysis is conducted based on shortage and holding cost under different bullwhip effect measures

analysis of compound bullwhip effect causes abstract this research investigates compound causes of the bullwhip effect bwe by considering an inventory system with multiple price sensitive demand streams joint price and demand dynamics are captured by a vector time series process that incorporates the stochastic co movements in price and demand we study two bwe measures one for each demand stream individually and one for the aggregated demand we show that demand parameters including demand autocorrelation cross correlation and price sensitivity serve as root causes of the bwe we prove that the impact of these parameters on the bwe can be additively decomposed conditions are established under which a pair of simultaneous compound causes may attenuate or dampen the bwe when demand streams are aggregated we derive a pooling factor that quantifies the impact of demand aggregation on order stability when positive the pooling factor corresponds to a synergy effect that captures the gain in the stability of the pooled orders conditions for the existence of the synergy effect are obtained for several special cases involving a zero leadtime we also discuss how our analytical findings can be managerially applied to bullwhip mitigation strategies

the impact of forecasting methods on the bullwhip effect abstract this paper considers the impact of forecasting methods on the bullwhip effect for a simple replenishment system in which a first order autoregressive process describes the customer demand and an order up to inventory policy characterizes the replenishment decision a bullwhip effect measure is derived for the optimal forecasting procedure that minimizes the mean squared forecasting error for the specified demand process similar measures are obtained for the moving average and exponential smoothing methods the findings indicate that different forecasting methods lead to bullwhip effect measures with distinct properties in relation to lead time and underlying parameters of the demand process moreover a simple rule is established to help managers select a forecasting method that yields the lowest inventory cost

a time series framework for supply chain inventory management we consider a supply chain in which the underlying demand process can be described in a linear state space form inventory is managed at various points of the chain members based on local information that each member observes and continuously updates the key feature of our model is that it takes into account the ability of the members to observe subsets of the underlying state vector and adopt their forecasting and replenishment policies accordingly this enables us to model situations in which the members are privy to certain explanatory variables of the demand with the latter possibly evolving according to a vector autoregressive time series for each member we identify an associated demand evolution model for which we propose an adaptive inventory replenishment policy that utilizes the kalman filter technique we then provide a simple methodology for assessing the benefits of various types of information sharing agreements between members of the supply chain we also discuss inventory positioning and cost performance assessment in the supply chain our performance metrics and inventory target levels are usually presented in matrix forms allowing them to accommodate a relatively large spectrum of linear demand models and making them simple to implement several illustrations for possible applications of our models are provided

a unified theory of the dynamics of closed loop supply chains we investigate the dynamics of a closed loop supply chain with first order auto regressive ar 1 demand and return processes we assume these two processes are cross correlated the remanufacturing process is subject to a random triage yield remanufactured products are considered as goodas new and used to partially satisfy market demand newly manufactured products make up the remainder we derive the optimal linear policy in our closed loop supply chain setting to minimise the manufacturer s inventory costs we show that the lead time paradox can emerge in many cases in particular the auto and cross correlation parameters and variances of the error terms in the demand and the returns as well as the remanufacturing lead time all influence the existence of the lead time paradox finally we propose managerial recommendations for manufacturers

empirical generalizations about market evolution and stationarity we present empirical generalizations about conditions under which marketing variables evolve or remain stationary we first define evolution statistically and make the case why it is an important concept for increasing our understanding of long run marketing effectiveness we then briefly review ways in which evolution can be tested empirically from readily available data we present a database of over 400 prior analyses and catalog the relative incidence of stationarity versus evolution in market performance and marketing spending we find that evolution is the dominant characteristic for sales and marketing mix spending but that stationarity is the dominant characteristic for market share thus we find strong support for the conjecture that many markets are in a long run equilibrium where the relative position of the players is only temporarily disturbed by their respective marketing activities we assess the impact of a number of covariates on the likelihood of finding stationarity evolution in sales

forecast frequency in rolling horizon hedging heuristics for capacity expansion this paper describes a simulation study of the effect of forecast revisions and hedges against demand uncertainty in a rolling horizon heuristic for capacity expansion the model is based on data collected in the utilities division of a large chemical manufacturing plant a seasonal integrated moving average model for the demand is used to generate forecasts while capacity additions are determined by applying a simple timing rule to various hedges around the forecast the simulation results indicate that hedging forecasts by their prediction limits rather than a fixed buffer significantly reduces undercapacity at the expense of a small increase in capacity cost the prediction limit hedge is more robust to delays in reforecasting

the effect of information sharing on supply chain stability and the bullwhip effect this paper analyzes the bullwhip effect in multi stage supply chains operated with linear and time invariant inventory management policies and shared supply chain information such information includes past order sequences and inventory records at all supplier stages the paper characterizes the stream of orders placed at any stage of the chain when the customer demand process is known and ergodic and gives an exact formula for the variance of the orders placed the paper also derives robust analytical conditions based only on inventory management policies to predict the presence of the bullwhip effect and bound its magnitude these results hold independently of the customer demand the general framework proposed in this paper allows for any inventory replenishment policies any ways of sharing and utilizing information and any customer demand processes it is also shown as a special case that sharing customer demand information across the chain significantly reduces but does not completely eliminate the bullwhip effect

measure of bullwhip effect in supply chains the case of high order autoregressive demand process abstract bullwhip effect the phenomenon in which variance of demand is amplified when moving upstream has attracted the attention of many researchers for the last few decades although the main sources that cause bullwhip effect have been identified quantifying the bullwhip effect still remains a challenge in the past measuring the bullwhip effect for supply chains with autoregressive demand process has been conducted by some researchers however most past researches focused mainly on the simple ar 1 model in many practical situations autoregressive models with higher order should be employed because they might better represent the demand process up to now very little effort has been spent on this matter therefore this research is conducted to fill this gap by first dealing with ar 2 demand process and investigating the behavior of the developed measure with respect to autoregressive coefficients and order lead time extension to the general ar p demand process is then considered

application of multi steps forecasting for restraining the bullwhip effect and improving inventory performance under autoregressive demand recent research suggests that the bullwhip effect or increasing variability of inventory replenishment orders as one moves up a supply chain illustrates inventory management inefficiencies this paper quantifies the bullwhip effect in the case of serially correlated external demand if autoregressive models are applied to obtain multiple steps demand forecasts a materials requirements planning mrp based inventory management approach is proposed to reduce the order variance simulation modeling is used to investigate the impact of the forecasting method selection on the bullwhip effect and inventory performance for the most downstream supply chain unit the mrp based approach is shown to reduce magnitude of the bullwhip effect while providing the inventory performance comparable to that of a traditional order up approach the application of autoregressive models compares favorably to other forecasting methods considered according to both the bullwhip effect and inventory performance criteria

short term variations and long term dynamics in commodity prices in this article we develop a two factor model of commodity prices that allows meanreversion in short term prices and uncertainty in the equilibrium level to which prices revert although these two factors are not directly observable they may be estimated from spot and futures prices intuitively movements in prices for long maturity futures contracts provide information about the equilibrium price level and differences between the prices for the short and long term contracts provide information about short term variations in prices we show that although this model does not explicitly consider changes in convenience yields over time this short term long term model is equivalent to the stochastic convenience yield model developed in gibson and schwartz 1990 we estimate the parameters of the model using prices for oil futures contracts and apply the model to some hypothetical oil linked assets to demonstrate its use and some of its advantages over the gibson schwartz model

information distortion in a supply chain the bullwhip effect this article originally appeared in management science april 1997 volume 43 number 4 pp 546 558 published by the institute of management sciences consider a series of companies in a supply chain each of whom orders from its immediate upstream member in this setting inbound orders from a downstream member serve as a valuable informational input to upstream production and inventory decisions this paper claims that the information transferred in the form of orders tends to be distorted and can misguide upstream members in their inventory and production decisions in particular the variance of orders may be larger than that of sales and distortion tends to increase as one moves upstream a phenomenon termed bullwhip effect this paper analyzes four sources of the bullwhip effect demand signal processing rationing game order batching and price variations actions that can be taken to mitigate the detrimental impact of this distortion are also discussed

get rid of unanimity rule the superiority of majority rules with veto power we study unanimous decision making under incomplete information we argue that unanimous decision rules are not all equivalent we show that majority rules with veto power are i pareto superior to commonly used unanimous rules and ii ex ante efficient in a broad class of situations

the bullwhip effect progress trends and directions the bullwhip effect refers to the phenomenon where order variability increases as the orders move upstream in the supply chain this paper provides a review of the bullwhip literature which adopts empirical experimental and analytical methodologies early econometric evidence of bullwhip is highlighted findings from empirical and experimental research are compared with analytical and simulation results assumptions and approximations for modelling the bullwhip effect in terms of demand forecast delay replenishment policy and coordination strategy are considered we identify recent research trends and future research directions concerned with supply chain structure product type price competition and sustainability

the bullwhip effect in supply chain networks this paper analyzes the propagation and amplification of order fluctuations i e the bullwhip effect in supply chain networks operated with linear and time invariant inventory management policies the supply chain network is allowed to include multiple customers e g markets any network structure with or without sharing information the paper characterizes the stream of orders placed by any supplier for any stationary customer demand processes and gives exact formulas for the variance of the orders placed and the amplification of order fluctuations the paper also derives robust analytical conditions based only on inventory management policies to predict the presence of the bullwhip effect for any network structure any inventory replenishment policies and arbitrary customer demand processes numerical examples show that the analytical results accurately quantify the bullwhip effect managerial insights are drawn from the analysis the methodology presented in this paper generalizes those in previous studies for serial supply chains

an arima supply chain model this paper presents a multistage supply chain model that is based on autoregressive integrated moving average arima time series models given an arima model of consumer demand and the lead times at each stage it is shown that the orders and inventories at each stage are also arima and closed form expressions for these models are given the paper also discusses the causes of the bullwhip effect a phenomenon in which variation in demand produces larger variations in upstream orders and inventory this discussion reveals how different modeling can lead to different insights because they make different assumptions about the cause of the bullwhip effect these observations are used to develop managerial insights about reducing the bullwhip effect

analysis of the bullwhip effect in two parallel supply chains with interacting price sensitive demands abstract this paper offers insights into how the bullwhip effect in two parallel supply chains with interacting price sensitive demands is affected in contrast to the situation of a single product in a serial supply chain in particular this research studies two parallel supply chains each consisting of a manufacturer and a retailer and the external demand for a single product depends on its price and the other s price in a situation in which each price follows a first order autoregressive process in this paper we propose an analytical framework that incorporates two parallel supply chains and we explore their interactions to determine the bullwhip effect we identify the conditions under which the bullwhip effect is amplified or lessened with interacting price sensitive demands relative to the situation without interaction

on bullwhip in a family of order up to policies with arma 2 2 demand and arbitrary lead times a number of papers have recently appeared that investigate the bullwhip effect the variance amplification of ordering decisions in the supply chain produced by the order up to replenishment policy an adapted policy with a proportional inventory position feedback controller has shown improved bullwhip behaviour the dynamic behaviour of this so called proportional order up to policy has been investigated for arbitrary lead times and several demand models such as i i d demand and autoregressive moving average ar 1 and arma 1 1 models it has been shown that for a correct choice of the feedback parameter the bullwhip effect can always be avoided however less attractive properties of this policy have also become clear herein we investigate the behaviour of the proportional order up to policy for arma 2 2 demand with arbitrary lead times in order to compensate for possible weaknesses of the proportional out policy we propose another replenishment rule that accounts for the characteristics of the demand in a superior manner the characteristics of both policies are compared for several parameter settings of the arma 2 2 model finally the consequences of our full state feedback order up to policy are discussed

inventories and the volatility of production a stylized fact associated with inventory behavior is that the variance of production exceeds the variance of sales this paper presents a model of production decisions with demand uncertainty that incorporates no nnegativity constraints on inventories even with no productivity shocks optimal behavior by the firm is consistent with this stylized fact either if demand exhibits positive serial correlation or if the firm can backlog excess demand the reason is that a demand shock affects both the actual inventory level given unchanged production and the desired level production must replenish the stock and adjust to the new desired level copyright 1987 by american economic association

reverse bullwhip effect in pricing price variability is one of the major causes of the bullwhip effect this paper analyzes the impact of procurement price variability in the upstream of a supply chain on the downstream retail prices procurement prices may fluctuate over time for example when the supply chain players deploy auction type procurement mechanisms or if the prices are dictated in market exchanges a game theory framework is used here to model a serial supply chain sequential price game scenarios are investigated to show that there is an increase in retail price variability and an amplified reverse bullwhip effect on prices rbp under certain demand conditions

the impact of information enrichment on the bullwhip effect in supply chains a control engineering perspective this paper examines the beneficial impact of information sharing in multi echelon supply chains we compare a traditional supply chain in which only the first stage in the chain observes end consumer demand and upstream stages have to base their forecasts on incoming orders with an information enriched supply chain where customer demand data e g epos data is shared throughout the chain two types of replenishment rules are analysed order up to out policies and smoothing policies policies used to reduce or dampen variability in the demand for the class of out policies we will show that information sharing helps to reduce the bullwhipeffect variance amplification of ordering quantities in supply chains significantly especially at higher levels in the chain however the bullwhip problem is not completely eliminated and it still increases as one moves up the chain for the smoothing policies we show that information sharing is necessary to reduce order variance at higher levels of the chain the methodology is based on control systems engineering and allows us to gain valuable insights into the dynamic behaviour of supply chain replenishment rules we also introduce acontrolengineering based measure to quantify the variance amplification bullwhip or variance reduction

combined pricing and inventory control under uncertainty this paper addresses the simultaneous determination of pricing and inventory replenishment strategies in the face of demand uncertainty more specifically we analyze the following single item periodic review model demands in consecutive periods are independent but their distributions depend on the item s price in accordance with general stochastic demand functions the price charged in any given period can be specified dynamically as a function of the state of the system a replenishment order may be placed at the beginning of some or all of the periods stockouts are fully backlogged we address both finite and infinite horizon models with the objective of maximizing total expected discounted profit or its time average value assuming that prices can either be adjusted arbitrarily upward or downward or that they can only be decreased we characterize the structure of an optimal combined pricing and inventory strategy for all of the above types of models we also develop an efficient value iteration method to compute these optimal strategies finally we report on an extensive numerical study that characterizes various qualitative properties of the optimal strategies and corresponding optimal profit values

an experimental study of the efficiency of unanimity rule and majority rule scholars traditionally claim that unanimity rule is more capable of producing pareto optimal outcomes than majority rule dougherty and edward public choice 151 3 655 678 2012 make the opposite claim assuming proposals are either random sincere or strategic we test these competing hypotheses in a two dimensional framework using laboratory experiments our primary results suggest 1 majority rule enters the pareto set more quickly than unanimity rule 2 majority rule leaves the pareto set at the same rate as unanimity rule and 3 majority rule is more likely to select a pareto optimal outcome than unanimity rule at the end of the game

the multivariate bullwhip effect abstract a multivariate bullwhip expression for m products with an order up to inventory policy is developed the demand models under consideration are differenced stationary vector time series with a wold representation for which general forecasting formulas are available resulting in a large class of possible models including nonstationary ones examples are provided for common demand models and implemented on sales data it is found that the multivariate approach gives rise to mechanisms for understanding and reducing the bullwhip effect through horizontal information sharing particularly for the nonstationary demand case in the stationary setting a more nuanced approach to bullwhip reduction can be achieved by managing the relationship between cross correlations and lead times a method of determining whether a multivariate or univariate approach generates a lower bullwhip effect is proposed

veto games spatial committees under unanimity rule there exists a large literature on two person bargaining games and distribution games or divide the dollar games under simple majority rule where in equilibrium a minimal winning coalition takes full advantage over everyone else here we extend the study to an n person veto game where players take turns proposing policies in an n dimensional policy space and everybody has a veto over changes in the status quo briefly we find a nash equilibrium where the initial proposer offers a policy in the intersection of the pareto optimal set and the pareto superior set that gives everyone their continuation values and punishments are never implemented comparing the equilibrium outcomes under two different agendas sequential recognition and random recognition we find that there are advantages generated by the order of proposal under the sequential recognition rule we also provide some conditions under which the players will prefer to rotate proposals rather than allow any specific policy to prevail indefinitely

comments on information distortion in a supply chain the bullwhip effect in this commentary we trace back how we pursued research on the bullwhip effect which resulted in the article published in management science we reflect on the evolution of this concept the impact that our work has had on industry the way our work has been used in the teaching of supply chain management and the key directions of research that have taken place since then

single versus multiple supplier sourcing strategies successful supply chain management necessitates an effective sourcing strategy to combat uncertainties in both supply and demand in particular supply disruption results in excessive downtime of production resources upstream and downstream supply chain repercussions and eventually a loss in the market value of the firm in this paper we analyze single period single product sourcing decisions under demand uncertainty our approach integrates product prices supplier costs supplier capacities historical supplier reliabilities and firm specific inventory costs a unique feature of our approach is the integration of a firm specific supplier diversification function we also extend our analysis to examine the impact of minimum supplier order quantities our results indicate that single sourcing is a dominant strategy only when supplier capacities are large relative to the product demand and when the firm does not obtain diversification benefits in other cases we find that multiple sourcing is an optimal sourcing strategy we also characterize a non intuitive trade off between supplier minimum order quantities costs and supplier reliabilities finally we examine the robustness of our results through an extensive numerical analysis of the key parameters of our model

mineral depletion with cost as the extraction limit a model applied to the behavior of prices in the nickel industry abstract this article follows papers by pindyck and heal and barrow in applying a hotelling type depletion model to a particular resource industry in this case that of nickel by means of the model the resource rent per ton of nickel is calculated as the proper index of extractive resource scarcity the time path of this resource rent indicates that the model explains industry behavior well and that as in the two previous studies depletion has been an important determinant of prices and rents in this industry

the value of formalism re examining external costs and decision costs with multiple groups several authors have examined the optimal k majority rule using a variety of criteria we formalize and extend the original argument laid out by buchanan and tullock the calculus of consent logical foundations of constitutional democracy 1962 using a decision theoretic analysis from the perspective of an individual voter unlike previous formalizations voters in our study are members of one or more groups this allows us to examine cases wherein different voters have starkly different interests furthermore voters in our study can err in their judgments of proposals allowing us to model potential irrationalities in the choice of an optimal k majority rule we consider both up or down votes on a single proposal as well as votes over a series of proposals we find that the optimal k majority rule depends on a number of parameters most notably the number of rounds needed to create a proposal that will pass group membership has almost no affect furthermore if two groups are at odds then the external cost function can actually rise over some range of k if voters err systematically in their judgment more inclusive k majority rules such as unanimity rule can fail to pass pareto preferred proposals our results should help advance a classic work in public choice

on 64 majority rule introduction d une definition de consensus social base sur deux restrictions une sur les preferences individuelles et l autre sur la distribution des preferences dans ce cas de consensus une regle de majorite a 64 presente de nombreuses proprietes interessantes par opposition aux regles de super majorite possedant des proprietes paradoxales comme les regles electorales americaines

an application of depletion theory to a base metal canadian nickel advances in economic theory in the past decade have considerably increased our understanding of the implications of the depletability of important natural resources this paper an application of that theory seeks to estimate the depletion charge which should be imputed to canadian nickel by first estimating the quality characteristics of remaining reserves rather strong assumptions are required to derive a charge in excess of five per cent of the metal s value and it is concluded that the imputation of a significant user cost to canadian metal production would not be socially optimal une application de la theorie de lepuisement a un metal de base le nickel au canada certains travaux de theorie economique ont consid6rablement accrfu notre comprehension des consequences de l 6puisement de certaines ressources naturelles importantes ce memoire est une application des resultats de ces travaux il veut 6valuer le cofut d epuisement le cofut qu on devrait imputer a la d6gradation du stock de nickel canadien en 6valuant la qualite des reserves de nickel qui restent il appert que l on doit faire des hypotheses assez extremes pour deriver un cofut impute de plus de cinq pourcents de la valeur du metal comme cofut de la d6gradation des stocks donc on peut conclure que l imputation d un cofut d 6puisement important sur la production canadienne ne serait pas socialement optimal

bullwhip effect and supply chain costs with low and high quality information on inventory shrinkage abstract inventory inaccuracy is the mismatch between the recorded inventory and the physical inventory which is severe and widespread in industry a few studies have investigated the bullwhip effect with the existence of inventory inaccuracy the development of information technologies has provided companies with access to accurate inventory information in real time this will surely affect the bullwhip effect and supply chain costs the aim of this paper is to build an analytical model to systematically investigate these effects we consider a retailer manufacturer supply chain in which the retailer faces inventory shrinkage which is the main cause of inventory inaccuracy both the situations with accurate real time inventory information i e high quality information and the situation with statistical inventory information i e low quality information are studied we examine the relationships between the bullwhip effect information distortion and supply chain costs with different levels of information quality the results of our analysis enrich the existing literature on the bullwhip effect first we show that the bullwhip effect is magnified along the chain when higher quality information on inventory shrinkage specifically real time rather than statistical data is obtained second we show that the magnification of the bullwhip effect does not necessarily result in higher costs third we demonstrate that higher quality information increases the benefits of information sharing our paper provides new insights into the causes extent and economic dynamics of order variability in the presence of inventory inaccuracy and may thus suggest ways of more effectively managing the bullwhip effect and inventory

the effect of replenishment policies on the bullwhip effect a transfer function approach an important phenomenon in supply chain management known as the bullwhip effect suggests that demand variability increases as one moves up a supply chain this paper examines the influence of different replenishment policies on the occurrence of the bullwhip effect the paper demonstrates that certain replenishment policies can in themselves be inducers of the bullwhip effect while others inherently lower demand variability the main causes of increase in variability are projections of future demand expectations which result in over exaggerated responses to changes in demand we suggest that through appropriate selection and use of certain replenishment rules the bullwhip effect can be avoided subsequently allowing supply chain management costs to be lowered

measure of bullwhip effect in supply chains with autoregressive demand process abstract in supply chain management one of the most critical problems which require a lot of effort to deal with is how to quantify and alleviate the impact of bullwhip effect the phenomenon in which information on demand is distorted while moving upstream although it is well established that demand forecast lead time order batching shortage gaming and price fluctuation are the main sources that lead to the bullwhip effect the problem of quantifying bullwhip effect still remain unsolved in many situations due to the complex nature of the problem in this research a measure of bullwhip effect will be developed for a simple two stage supply chain that includes only one retailer and one supplier in the environment where the retailer employs base stock policy for their inventory and demand forecast is performed through the first order autoregressive model ar 1 the effect of autoregressive coefficient and lead time on this measure will then be investigated

voting for pareto optimality a multidimensional analysis we compare unanimity rule and majority rule in their abilities to produce pareto superior and pareto optimal alternatives in fixed number of rounds of voting using a two dimensional spatial voting model with random proposals sincere proposals and strategic proposals our findings show that for random or sincere proposals majority rule is at least as likely to select a pareto optimal outcome as unanimity rule for strategic proposals the subgame perfect equilibrium under unanimity rule is pareto optimal for other k majority rules the outcome is pareto optimal or very close to it for outcomes that are both pareto optimal and pareto superior unanimity rule outperforms majority rule

characterization of the bullwhip effect in linear time invariant supply chains some formulae and tests the authors analyze the bullwhip effect in multistage decentralized supply chains operated with linear and time invariant inventory management policies the focus is on robustness the supply chain is modeled as a single input single output control system driven by arbitrary customer demands the authors derive robust analytical conditions to predict the presence of the bullwhip effect and bound its magnitude based only on the way inventories are managed these results hold independently of the customer demand the authors also characterize the stream of orders placed at any stage of the chain when the customer demand process is known and ergodic and give an exact formula for the variance of the orders placed this formula generalizes existing results by broadening the class of inventory replenishment policies and customer demand processes to which it applies the authors also show that the bullwhip effect can be mitigated by introducing commitments for future orders into the ordering policies

measuring and avoiding the bullwhip effect a control theoretic approach an important contributory factor to the bullwhip effect i e the variance amplification of order quantities observed in supply chains is the replenishment rule used by supply chain members first the bullwhip effect induced by the use of different forecasting methods in order up to replenishment policies is analysed variance amplification is quantified and we prove that the bullwhip effect is guaranteed in the order up to model irrespective of the forecasting method used thus when production is inflexible and significant costs are incurred by frequently switching production quantities up and down order up to policies may no longer be desirable or even achievable in the second part of the paper a general decision rule is introduced that avoids variance amplification and succeeds in generating smooth ordering patterns even when demand has to be forecasted the methodology is based on control systems engineering and allows important insights to be gained about the dynamic behaviour of replenishment rules