estimating residential demand for electricity in greece abstract this paper examines the residential demand for electricity in greece the issues of structural stability price and income sensitivity of both long and short run residential demand for electricity in greece were examined employing monthly data over the period 1986 1999 the long run residential demand for electricity is estimated taking into account changes in weather conditions weighted by the size of the population employing multivariate framework analysis a long run residential demand function for electricity sensitive to real income price level and weather conditions is found to exist and the importance of short run deviations is presented using vector error correction model vecm estimation the empirical evidence suggests the presence of a stable residential demand for electricity in greece both in the long and short run periods and the policy implications of such a relationship are presented

strategic capacity rationing to induce early purchases dynamic pricing offers the potential to increase revenues at the same time it creates an incentive for customers to strategize over the timing of their purchases a firm should ideally account for this behavior when making its pricing and stocking decisions in particular we investigate whether it is optimal for a firm to create rationing risk by deliberately understocking products then the resulting threat of shortages creates an incentive for customers to purchase early at higher prices but when does such a strategy make sense if it is profitable to create shortages what is the optimal amount of rationing risk to create we develop a stylized model to study this problem in our model customers have heterogeneous valuations for the firm s product and face declining prices over two periods customers are assumed to have identical risk preferences and know the price path and fill rate in each period via its capacity choice the firm is able to control the fill rate and hence the rationing risk faced by customers customers behave strategically and weigh the payoff of immediate purchases against the expected payoff of delaying their purchases we analyze the capacity choice that maximizes the firm s profits first we consider a monopoly market and characterize conditions under which rationing is optimal we examine how the optimal amount of rationing is affected by the magnitude of price changes over time and the degree of risk aversion among customers we then analyze an oligopoly version of the model and show that competition reduces the firms ability to profit from rationing indeed there exists a critical number of firms beyond which a rationing equilibrium cannot be supported

optimal dynamic pricing of inventories with stochastic demand over finite horizons in many industries managers face the problem of selling a given stock of items by a deadline we investigate the problem of dynamically pricing such inventories when demand is price sensitive and stochastic and the firm s objective is to maximize expected revenues examples that fit this framework include retailers selling fashion and seasonal goods and the travel and leisure industry which markets space such as seats on airline flights cabins on vacation cruises and rooms in hotels that become worthless if not sold by a specific time we formulate this problem using intensity control and obtain structural monotonicity results for the optimal intensity resp price as a function of the stock level and the length of the horizon for a particular exponential family of demand functions we find the optimal pricing policy in closed form for general demand functions we find an upper bound on the expected revenue based on analyzing the deterministic version of the problem and use this bound to prove that simple fixed price policies are asymptotically optimal as the volume of expected sales tends to infinity finally we extend our results to the case where demand is compound poisson only a finite number of prices is allowed the demand rate is time varying holding costs are incurred and cash flows are discounted the initial stock is a decision variable and reordering overbooking and random cancellations are allowed

seasonality and the production smoothing model abstract the debate over whether firms smooth production relative to demand continues in this paper we find that results obtained in blinder quarterly journal of economics 101 3 1986 431 453 and blinder and maccini journal of economic surveys 5 4 1991 293 328 indicating that firms do not smooth production are greatly influenced by the seasonal adjustment of the census data for us manufacturing using seasonally adjusted data we find significant evidence of production smoothing in 10 of 14 manufacturing industries for the years 1982 1997 further the prevalence of production smoothing has increased over time which we attribute either to fundamental changes in the collection of the data or to the advent of improved methods of inventory management

market price behavior of wholesale electricity products texas abstract applying a regression based approach to a newly developed sample of over 60 000 hourly observations for 01 01 2011 12 30 2017 we answer the question what moves the day ahead market dam prices for energy and ancillary services as and the real time market rtm price for energy in the electric reliability council of texas ercot our answer comprises the following findings that capture the interdependence of ercot s energy and as products 1 the dam energy price increases with the day ahead forecasts of natural gas price system load and as requirements but declines with nuclear and wind generation s forecasts 2 the as prices increase with the dam energy price and the as procurement forecasts but decline with the as offer forecasts and 3 the rtm energy price increases with the dam energy price but diverges from the dam energy price due to forecasting errors related to the dam energy price s fundamental drivers these findings imply that texas can reduce the prices for day ahead energy day ahead as and real time energy via wind generation development and demand side management further texas can improve its electricity trading efficiency by improving ercot s forecast accuracy to narrow the rtm energy price s divergence from the dam energy price

do farmers benefit from participating in specialty markets and cooperatives the case of coffee marketing in costa rica1 historically low prices in the conventional coffee market have caused financial and social hardship among coffee farmers in the face of this crisis specialty markets have attracted the attention of the international donor community these market segments have shown consistent growth over the last decade and exhibit price premiums in international markets therefore if higher prices are passed on to farmers access to specialty markets could help to alleviate the crisis brought on by low prices in the conventional sector the present study attempts to identify the factors that determine farmers participation in specialized markets and whether participation in these markets leads to higher prices for farmers a two stage model is used to analyze farmers marketing decisions and their effect on the prices received this procedure allows us to control for the endogeneity bias introduced by the marketing choice our results indicate that farmers participating in the specialty coffee segment do in fact receive higher prices than those participating in conventional channels additionally we find that participation in cooperatives has a positive impact on the probability that a farmer chooses to grow specialty coffee and analogously on the prices that they receive based on these results it seems that efforts to increase participation in the specialty coffee segment and in cooperatives would help to lessen some of the hardships brought on by low prices in the conventional coffee sector

dynamic pricing with real time demand learning in many service industries the firm adjusts the product price dynamically by taking into account the current product inventory and the future demand distribution because the firm can easily monitor the product inventory the success of dynamic pricing relies on an accurate demand forecast in this paper we consider a situation where the firm does not have an accurate demand forecast but can only roughly estimate the customer arrival rate before the sale begins as the sale moves forward the firm uses real time sales data to fine tune this arrival rate estimation we show how the firm can first use this modified arrival rate estimation to forecast the future demand distribution with better precision and then use the new information to dynamically adjust the product price in order to maximize the expected total revenue numerical study shows that this strategy not only is nearly optimal but also is robust when the true customer arrival rate is much different from the original forecast finally we extend the results to four situations commonly encountered in practice unobservable lost customers time dependent arrival rate batch demand and discrete set of allowable prices

have coffee producers benefited from the new domestic cherry market evidence using panel data from rwanda the article assesses the effects of the new domestic cherry market on coffee growing households in rwanda using panel data findings from combined first differenced with instrumental variable specification and other estimation methods provide evidence that farmers who sell to the cherry market do not increase their expenditures compared to farmers selling to the traditional parchment market the different time lags in terms of when farmers started selling to the new cherry market may explain the lack of statistically significant differences across the two groups it is possible that farmers will adjust their expenditure patterns in subsequent periods after year over year market trends become more apparent to them

classical and variance bounds tests of the production smoothing hypothesis in this paper we test the controversial production smoothing role of inventories by applying both classical econometric techniques and variance bounds tests we use seasonally unadjusted data measured in physical units for five industries the model used is a version of the familiar holt et al 1960 inventory model we also use the data on one industry disaggregated at the district level to investigate potential bias which may arise from aggregation overall the empirical evidence suggests production smoothing in the great majority of the industries examined

participation in the farmer owned reserve program a discrete choice model the food and agriculture act of 1977 initiated a fundamental redirection of u s grain policy previous grain policy revolved around supply control via price supports and marketing quotas or allocations now the active role of grain reserves is emphasized the market is given free rein under normal conditions while grain reserves guard against periods of excessively high or low prices a cornerstone of the new policy is the farmer owned reserve for program the for is designed to stabilize grain prices and contribute to food security by encouraging farmers to hold more grain in storage than they would otherwise because the program is voluntary it is important to understand what motivates participation in the for it is also important to quantify at least partially the decision making process if policy makers are to forecast farmer responsiveness to policy actions in recent studies addressing this question little attention has been given to statistical modelling of individual decision making meyers and ryan meyers jolly and ryan burnstein this paper describes an empirical model of the for participation decision using a theoretical choice model and discrete econometrics the major provisions of the for are first outlined next a theoretical choice model based on a stochastic utility function is presented crosssection data for corn and wheat producers gathered by a subcommittee of north central regional project 152 nc 152 are used to estimate empirical models of the decision making process the paper concludes with pertinent policy implications the farmer owned grain reserve

measuring noise in inventory models this paper has two purposes one is to assess different models of inventory behavior in terms of their ability to approximate the realized data we do this initially for the pure production smoothing model and then for a sequence of generalizations our analysis both performs specification tests as well as measures the deviations of the data from each null model through use of a noise ratio statistic a second purpose is to explore whether observed cost shocks in particular raw materials prices help explain inventory movements we find that the production smoothing model of inventories augmented by buffer stock motives stockout avoidance motives and observed cost shocks well approximates monthly data

temporal aggregation and estimation of inventory functions abstract in this paper we extend the analysis of the effects of aggregation on the estimated speed of adjustment in inventory models into two directions first we try to find out if lovell s 1993 conclusions regarding the effects of aggregation on the speed of adjustment hold a when real firm data rather than experimental data are used b when the model is modified or when models other than the flexible accelerator are used secondly we examine whether temporal aggregation also leads to underestimation when disaggregated nonseasonally adjusted data are used the evidence we provide gives strong support to mundlak s and zellner s conjectures cited in christiano and eichenbaum 1987 that temporal aggregation leads to downward bias in the estimated speed of adjustment

a multi sector inventory model abstract two competing paradigms for firm level inventory behavior are production smoothing and s s empirical evidence that aggregate production varies more than sales and inventory investment is positively correlated with sales appears to contradict the buffer stock production smoothing motivation work by blinder and maccini suggests that an s s model better explains these stylized facts i simulate a multi sector model with sequential interaction of heterogeneous agents representing manufacturing wholesale and retail agents who use either smoothing or s s inventory decision rules the results demonstrate that the stylized facts can be explained by a model of this type

consistent estimation of a disequilibrium model of primary commodity price adjustment 1990 consistent estimation of a disequilibrium model of primary commodity price adjustment applied economics vol 22 no 10 pp 1417 1426

an empirical test of the effect of excess capacity in price setting capacity constrained supergames abstract in a multi period game industry excess capacity may act to deter firms from cheating on a non cooperative oligopoly price a model is developed that translates the deterrrent influence of excess capacity into predictions about the relationship between excess capacity and oligopoly price cost margins the model is tested with time series data from the u s aluminum industry results are consistent with those predicted by the model

simulating the inventory cycle abstract simulations of the inventory cycle utilizing a model based on 84 interacting firms in 21 industries reveals that the ratio of the variance of sales to the variance of output is an unreliable indicator of how seriously firms attempt to smooth production or whether such efforts in the aggregate even out economic fluctuations it is also shown that the two slow estimates of the speed of adjustment reported in many econometric studies of united states data may result in part from aggregation bias rather than from limitations of the flexible accelerator model itself

demand generation and price in the norwegian market for electric power we analyse the simultaneous determination of supply demand and price in the competitive norwegian electricity market deregulated in 1991 this market is pretty mature and it offers numerous data required carrying out an interesting study stochastic and seasonal water inflow water storage possibilities and demand variations make this market interesting both from a theoretical and empirical view we establish a small supply demand model of the norwegian electricity market the model is estimated using weekly data from 1994 to 1995 data for 1996 are used for post sample examination of the model unexpected inflow snow and temperature conditions explain a large part of the variation in the electricity generation demand and price within and post sample simulation of the estimated model reproduce demand and price patterns considerably well

measuring the convexity of the cost function abstract in this paper i argue that as might be expected the initial assumption made about the cost function will influence the empirical results obtained regarding the convexity i show that this expectation is supported empirically by estimating the parameters of two quadratic cost functions the first is that function which has been traditionally used in the literature the second is a simplified version of the quadratic cost function where the cost of changing the level of output is dropped since the evidence in the literature suggest that this variable has no significant effect on cost using physical product monthly data for 24 industries we find that the conclusion reached regarding the convexity of the cost function depends on the assumption we make regarding the cost function i further find that the simplified function is consistent with the observed behavior of production and sales while the traditional cost function is inconsistent with that behavior

actively learning about demand and the dynamics of price adjustment by observing the quantity demanded at particular prices a firm may learn about the parameters of its demand curve in such an environment price changes obstruct the learning process by inducing additional noise the authors paper constructs a dynamic model where a price setting firm endogenously controls the speed of learning the model provides a possible explanation for price inertia as a stable pricing policy allows the firm to learn more rapidly which improves future expected profits furthermore even in the long run learning continues to affect the firm s optimal price copyright 1990 by royal economic society

input and output inventories abstract this paper presents a new stage of fabrication inventory model with delivery usage and stocks of input materials that distinguishes between gross production and value added it extends the linear quadratic model of output inventories by adding the joint determination of input inventories empirically input inventories are more important than output inventories maximum likelihood estimation of the decision rules yields correctly signed and significant parameter estimates using data for nondurable and durable goods industries but the overidentifying restrictions of the model are rejected the value added specification dominates because adjustment costs on materials usage are critical to fitting the data

accounting for output fluctuations in manufacturing there is a substantial body of evidence to the effect that output is more volatile than sales among manufacturing industries numerous explanations have been advanced to account for this excess output volatility some examples are pro cyclical inventory movements induced by a stockout avoidance motive cost and technology shocks and decreasing marginal costs this article assesses the contribution of these different motives to output volatility for six different manufacturing industries linear quadratic models are estimated for each of the industries and then dynamic simulations are employed to determine the volatility of output when one or more of the factors are removed from the model technology shocks provide the most significant contribution to output volatility the stockout avoidance motive is also important cost shocks provide a very small contribution and marginal production costs are increasing at the margin and thus stabilize output it is also shown that output volatility declines when curre

seasonality aggregation and the testing of the production smoothing hypothesis one of the leading hypotheses concerning the dynamics of production over time is the production smoothing hypothesis given a planning horizon which spans a number of production periods the firm need not produce in each period an amount equal to expected sales rather resorting to inventory accumulation and liquidation the firm may follow a production plan temporally smoother than the path of demand if firms faced with convex cost functions chose to smooth the rate of output in order to minimize costs one would expect to observe that the rate of output would vary less than the rate of sales with variations in inventory stocks absorbing some of the fluctuations in sales recently work on the testing of the production smoothing hypothesis has cast doubt on its empirical validity the evidence presented by alan blinder seems to indicate that the variance of production exceeds that of sales in seven out of eight two digit retail industries 1981 and in eighteen out of twenty two digit manufacturing industries 1983 and 1986 the purpose of this paper then is to examine the validity of such tests when seasonally adjusted aggregated data are used the evidence presented show that the relative size of the variances of the seasonally adjusted production and sales does not provide valid tests of the production smoothing hypothesis in addition aggregating over firms where the seasonal patterns differ may also distort tests of production smoothing blinder realized that the use of seasonally adjusted data may not provide an adequate test of the hypothesis stating had they been available i would have preferred to use data that were not seasonally adjusted since the production smoothing model presumably applies to seasonal fluctuations in sales however such data are not available 1983 fn 19 in this paper i focus on the cement industry because the unadjusted disaggregated data are available for the direct testing of the conjecture that aggregate seasonally adjusted data mask production smoothing phenomenon aggregate monthly data on five other industries will also be examined

tests of production smoothing in selected japanese industries abstract using monthly physical quantity data on production sales and inventories for 29 selected japanese industries it is found that the usual variance decompositions are generally consistent with the production smoothing model at both seasonal and nonseasonal frequencies however the estimated seasonal coefficients in production and sales are highly correlated which should not be the case if firms smooth production in the face of anticipated seasonal movements in sales a further test of the model which implies production should follow a random walk with drift provides mixed results but particularly negative results at the seasonal frequencies

deregulated power prices comparison of diurnal patterns we examine electrical power price and in particular its daily and average weekday vs weekend pattern of change for 14 deregulated markets power price in deregulated markets shows fundamentally different patterns north american markets show a monotonic diurnal weekday price pattern while all other markets studied show more than one price peak deregulated power markets differ in maximum vs minimum daily average price and in average weekday to weekend price in turn creating a different incentive for a consumer to time shift power consuming activities markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price deregulated markets show a wide variation in the correlation between load and price some deregulated markets most notably britain and spain show patterns that are predictable and consistent and hence that can encourage a customer to shape consumption behaviors other markets for example south australia have patterns that are inconsistent and irregular and hence are hard for a customer to interpret a customer in such a market will have a higher incentive to escape risk through hedging mechanisms

on the minimax complexity of pricing in a changing environment we consider a pricing problem in an environment where the customers willingness to pay wtp distribution may change at some point over the selling horizon customers arrive sequentially and make purchase decisions based on a quoted price and their private reservation price the seller knows the wtp distribution pre and postchange but does not know the time at which this change occurs the performance of a pricing policy is measured in terms of regret the loss in revenues relative to an oracle that knows the time of change prior to the start of the selling season we derive lower bounds on the worst case regret and develop pricing strategies that achieve the order of these bounds thus establishing the complexity of the pricing problem our results shed light on the role of price experimentation and its necessity for optimal detection of changes in market response wtp our formulation allows for essentially arbitrary consumer wtp distributions and purchase request patterns

the effects of commodity price stabilization programs in this paper the authors analyze the effects of commodity programs in which the government attempts to support and stabilize price through open market purchases and sales specifically they as sess the effects of such programs on the u s soybean market using a rational expectations model that allows for private storage expected price responsive production and arbitrary support and release price s a salient feature of the model is that private storage and product ion behavior adjusts to changes in government policy stochastic simu lations of the market model demonstrate that price stabilization prog rams can reduce long run market price and destabilize producer revenu e copyright 1988 by american economic association

the rational effect of price promotions on sales and consumption we explore the rational effect of price variation on sales and consumption in markets where consumers are uncertain about the future price of goods we first derive an optimal ordering policy which expresses the amount a consumer should purchase and consume in a given period as a function of the observed price of the good the distribution of future prices and the nature of his or her inventory this policy extends previous normative models of inventory control such as those by golabi 1985 and kalymon 1970 to the case where the amount to consume in a given period is an explicit decision variable and prices follow a first order stochastic process we then use this model to explore how changes in the long run frequency and temporal correlations of price promotions should normatively affect the contemporaneous relationship between purchase consumption and price among the predictions which follow from the model are that consumption should rationally increase with the size of existing inventories the short term sensitivity of sales to prices should be greater than that of consumption to price and this discrepancy increases with decreases in the temporal correlation of price deals and the long term relative frequency of price deals

dynamic pricing in the presence of strategic consumers and oligopolistic competition we present a dynamic pricing model for oligopolistic firms selling differentiated perishable goods to multiple finite segments of strategic consumers who are aware that pricing is dynamic and may time their purchases accordingly this model encompasses strategic behavior by both firms and consumers in a unified stochastic dynamic game in which each firm s objective is to maximize its total expected revenues and each consumer responds according to a shopping intensity allocation consumer choice model we prove the existence of a unique subgame perfect equilibrium provide equilibrium optimality conditions and prove monotonicity results for special cases the model provides insights about equilibrium price dynamics under different levels of competition asymmetry between firms and multiple market segments with varying properties we demonstrate that strategic behavior by consumers can have serious impacts on revenues if firms ignore that behavior in their dynamic pricing policies moreover ideal equilibrium responses to consumer strategic behavior can recover only a portion of the lost revenues a key conclusion is that firms may benefit more from limiting the information available to consumers than from allowing full information and responding to the resulting strategic behavior in an optimal fashion

the speed of adjustment and production smoothing bayesian estimation abstract the models used for empirical studies of inventory behavior typically include the lagged stock of inventories as a result of the partial adjustment assumption and also exhibit serial correlation in the residuals some researchers suggested that the very low speed of adjustment of the actual inventories to their desired levels and also the lack of empirical support for the production smoothing hypothesis may be the results of applying inappropriate estimation methods to the data recently a bayesian estimator that applies to models containing both lagged dependent variables and autocorrelated disturbances was developed in this paper we examine the empirical evidence on the speed of adjustment of inventories to their desired levels and the degree to which firms smooth production by applying this new estimation method to monthly industry data the results show that the low speeds of adjustment reported in the literature as well as the low degree or lack of production smoothing also reported in the literature may indeed be artifacts of the estimation procedures used

modelling market fundamentals a model of the aluminium market the standard approach to modelling primary commodity markets under rational expectations is to relate the commodity price to the production and consumption surprises i e the innovations on the equations using the world aluminium market we show how this approach can be modified so that both the price and stock can be written in terms of one or more market fundamentals which reflect the supply demand balance on the market this approach allows joint estimation of production consumption stock demand and price equations subject to cross equation restrictions it may be seen as a formalization of the approach adopted by metals industry analysts

production smoothing in the japanese vehicle industry abstract physical data from the japanese vehicle industry covering monthly observations from 1985 1 to 1994 12 are investigated across nine goods ranging from bicycles to large buses smaller variance of production is found relative to sales across all goods for unadjusted data and in 17 out of 18 cases for seasonally adjusted data such evidence in favor of the production smoothing model psm is confirmed by full information maximum likelihood employed jointly on inventories and sales equations the estimates suggest the industry operates in the range of increasing marginal costs in six out of nine goods positive costs of being away from targeted inventory are also present in six out of these nine goods which make the psm a good description of this industry

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 resurgence of inventory research what have we learned abstract recent empirical and theoretical research on business inventories is surveyed and critically evaluated while most inventory research has had macroeconomic motivations we focus on its microtheoretic basis and on potential conflicts between theory and evidence the paper asks two principal questions first how can inventories which are allegedly used by firms to stabilize production nonetheless be a destabilizing factor at the macroeconomic level second why if firms are following the production smoothing model is production more variable than sales in many industries we suggest that the so called s s model may help answer both questions

paying for environmental services an analysis of participation in costa rica s psa program summary costa rica has long been a leader among developing countries in the design of and experimentation with innovative environmental programs since 1997 costa rica s pagos de servicios ambientales payments for environmental services program has provided payments to more than 4 400 farmers and forest owners for reforestation forest conservation and sustainable forest management activities econometric analysis of a survey of farmers and forest owners including both psa participants and nonparticipants shows that farm size human capital and household economic factors and information variables significantly influence participation in psa program alternatives large farmers and forest owners are disproportionately represented among program participants

bayesian dynamic pricing policies learning and earning under a binary prior distribution motivated by applications in financial services we consider a seller who offers prices sequentially to a stream of potential customers observing either success or failure in each sales attempt the parameters of the underlying demand model are initially unknown so each price decision involves a trade off between learning and earning attention is restricted to the simplest kind of model uncertainty where one of two demand models is known to apply and we focus initially on performance of the myopic bayesian policy mbp variants of which are commonly used in practice because learning is passive under the mbp that is learning only takes place as a by product of actions that have a different purpose it can lead to incomplete learning and poor profit performance however under one additional assumption a constrained variant of the myopic policy is shown to have the following strong theoretical virtue the expected performance gap relative to a clairvoyant who knows the underlying demand model is bounded by a constant as the number of sales attempts becomes large this paper was accepted by gerard p cachon stochastic models and simulation

strategic waiting for consumer generated quality information dynamic pricing of new experience goods in this paper we study the impact of consumer generated quality information e g consumer reviews on a firm s dynamic pricing strategy in the presence of strategic consumers such information is useful not only to the consumers that have not yet purchased the product but also to the firm the informativeness of the consumer generated quality information depends however on the volume of consumers who share their opinions and thus depends on the initial sales volume hence via its initial price the firm not only influences its revenue but also controls the quality information flow over time the firm may either enhance or dampen the quality information flow via increasing or decreasing initial sales the corresponding pricing strategy to steer the quality information flow is not always intuitive compared to the case without consumer generated quality information the firm may reduce the initial sales and lower the initial price interestingly the firm may get strictly worse off due to the consu

an empirical investigation on causes and effects of the bullwhip effect evidence from the personal care sector abstract this paper analyses the empirical demand data for fast moving consumer goods to measure the bullwhip effect the data consist of the sell in from a large manufacturer to the retailers and the sell out from a retailer to the consumers our findings show that the bullwhip effect can be substantial indeed in more than 50 of the cases the demand upstream sell in is twice as variable as the demand downstream sell out however in other cases it can be negligible and in one case the demand upstream is slightly less variable than the demand downstream so while the bullwhip effect can be very large it need not be so finally we attempted to delve into the dynamics that generate a significant bullwhip effect and discovered that among the various causes that create the bullwhip effect discussed by lee et al 1997a price fluctuations and forward buys driven by sales targets play a decisive role we show that the flatter the final consumer demand sell out the more room there is for the retailers to forward buy in order to take advantage of the deals offered by the manufacturer s sales force toward the end of the sales period on the contrary the more variable the final consumer demand the less willing the retailer is to make a risky inventory investment and thus the more the retailer s orders closely follow consumer demand this result at the product family level is very consistent with the results that cachon et al 2007 obtained at the company industry level

merit order effects of renewable energy and price divergence in california s day ahead and real time electricity markets abstract we answer two policy questions 1 what are the estimated merit order effects of renewable energy in the california independent system operator s caiso s day ahead market dam and real time market rtm and 2 what causes the hourly dam and rtm prices to systematically diverge the first question is timely and relevant because if the merit order effect estimates are small california s renewable energy development is of limited help in cutting electricity consumers bills but also has a lesser adverse impact on the state s investment incentive for natural gas fired generation the second question is related to the efficient market hypothesis under which the hourly rtm and dam prices tend to converge using a sample of about 21 000 hourly observations of caiso market prices and their fundamental drivers during 12 12 2012 04 30 2015 we document statistically significant estimates p value 0 01 for the dam and rtm merit order effects this finding lends support to california s adopted procurement process to provide sufficient investment incentives for natural gas fired generation we document that the rtm dam price divergence partly depends on the casio s day ahead forecast errors for system loads and renewable energy this finding suggests that improving the performance of the caiso s day ahead forecasts can enhance trading efficiency in california s dam and rtm electricity markets

production smoothing evidence from physical product data we reconsider the paradox that the variance of production often exceeds the variance of shipments a result that casts doubt on the production smoothing model of inventory behavior most studies of production smoothing have analyzed two digit sic dollar value data from commerce department surveys in contrast this paper examines disaggregated physical product data and finds that production is smoother than shipments in about two thirds of the 38 industry or product groupings considered however doubts about the model persist most notably euler equation estimates of the model s cost parameters are usually imprecise and often do not have the signs postulated by production smoothing models

the response by the norwegian aluminium industry to changing market structure abstract this paper analyses how changes in market structure have affected the margins measured by the lerner index of norwegian aluminium plants instead of showing the expected negative trend due to increased competition internationally the margins are found to move procyclically around a constant that significantly exceeds zero three explanations for this stability in the levels of the margins are identified a better exploitation of scale economies increased productivity and product specialisation which allows norwegian producer prices to increase more rapidly than the international reference price

dynamic pricing with online learning and strategic consumers an application of the aggregating algorithm we study the problem faced by a monopolistic company that is dynamically pricing a perishable product or service and simultaneously learning the demand characteristics of its customers in the learning procedure the company observes the sales history over consecutive learning stages and predicts consumer demand by applying an aggregating algorithm aa to a pool of online stochastic predictors numerical implementation uses finite sample distribution approximations that are periodically updated using the most recent sales data these are subsequently altered with a random step characterizing the stochastic predictors the company s pricing policy is optimized with a simulation based procedure integrated with aa the methodology of the paper is general and independent of specific distributional assumptions we illustrate this procedure on a demand model for a market in which customers are aware that pricing is dynamic may time their purchases strategically and compete for a limited product supply we derive the form of this demand model using a game theoretic consumer choice model and study its structural properties numerical experiments demonstrate that the learning procedure is robust to deviations of the actual market from the model of the market used in learning

the behavior of manufacturers inventories evidence from us industry level data abstract recent empirical research on inventory behavior makes extensive use of disaggregated data both from the 20 two digit manufacturing industries identified in the standard industrial classification sic system and physical product data from lower levels of aggregation economists have traditionally grouped these industries by durability of final product or by the presence or absence of unfilled orders for comparison recent research by mattey and strongin economic review federal reserve bank of san francisco 2 1997 3 17 suggests that production technology affects the flow of material through the production process and the use of labor and capital in manufacturing a review of the empirical inventory literature reveals patterns that can be explained by differences in production technology in studies that use both two digit industry data and disaggregated physical product data from four and five digit industries thus there may be more heterogeneity in disaggregated inventory data than was previously thought

a hybrid system econometric model for electricity spot prices considering spike sensitivity to forced outage distributions with the current trend in deregulation all electricity markets have been subject to volatile electricity prices typically in peak season as markets mature new financial and operational risk management instruments are becoming available in order to price such instruments a model for the underlying price process is required in this paper a hybrid model is described that contains aspects of the power system as well as the historical time series of spot prices observed in the market by including both aspects of the problem a model with both economic and system based aspects is created its modular design allows easy adaptation to different markets based on generating system reliability load patterns and price histories the spot price histories are manifest in two probability distributions for these prices whereas the system specifics are included via load and generation models which are calibrated to the climate and system of interest

real time pricing in the nordic power markets abstract in this paper we study the potential effects of real time pricing rtp of electricity on the need for long run capacities in the nordic power markets a characteristic of the nordic power market is the large variety of production technologies of which hydro and nuclear power are capacity constrained we analyze the impact of rtp on the need for total peak and midmerit capacities total demand prices peak demand hours and economic welfare we have also studied whether the results of rtp are sensitive to the simultaneous implementation of tradable emission permits we find that rtp diminishes the need for total capacity even with inelastic demand our results show that even with modest assumptions related to rtp participation the annual midmerit and peaker capacity efficiency savings amount to 97 million euros which are around 6 of their total annual investment costs the price of the peak demand hour clearly diminishes as the share of the rtp customers increases or demand becomes more price elastic we compare rtp and tradable emission permits as two separate instruments in reaching energy use efficiencies and show how these two instruments must be seen as complementary and not as substitutable instruments we show how rtp and tradable emission permits have a positive correlation in promoting market access of renewable energy sources we find that welfare effects of the implementation of rtp are positive

gaming the uniform price spot market quantitative analysis in this paper a range of indices have been derived to quantify the incentives to game the uniform price spot market the gain of a portfolio generator due to withdrawing capacity and or inflating the price bid has been found to be proportional to the in merit market share of the gaming generator and the inverse combined price elasticity of supply demand a gaming index has also been derived as a modification of the herfindahl hirschman index which takes into account the reduction in the number of competitors as the demand goes up and the benefit the portfolio generators take from gaming price elastic loads reduce gaming opportunities but do not remove them application of the indices has been illustrated using the the spot market in england and wales the results seem to confirm practical evidence from many countries that spot markets are vulnerable to gaming

optimal price skimming by a monopolist facing rational consumers this paper considers the intertemporal pricing problem for a monopolist marketing a new product the key feature differentiating this paper from the extant management science literature on intertemporal pricing is the assumption that consumers are intertemporal utility maximizers a subgame perfect nash equilibrium pricing policy is characterized and shown to involve intertemporal price discrimination we compare this policy to the optimal policy for a monopolist facing myopic consumers and find that for any given state prices are always lower with rational consumers than with myopic consumers for plausible parameter values the assumption of consumer rationality can be shown to lead to large differences in optimal prices moreover if a monopolist facing rational consumers implements the optimal myopic consumer pricing policy profits can be significantly less than if the monopolist follows the equilibrium pricing policy for rational consumers

the production smoothing model is alive and well abstract monthly data in physical units for seven industries are used to examine the production smoothing hypothesis the results strongly support this hypothesis significant effects of expected future sales on current production are found for four industries and the estimated decision equations for all seven industries imply production smoothing behavior the previous negative results appear to be due to the use of data biased against the hypothesis the shipments and inventory data of the department of commerce the paper also shows that sensible results can be obtained from estimating approximations to decision equations as opposed to estimating euler equations

volatility of sales expectation errors and inventory investment firm level evidence abstract this paper tests whether demand uncertainty which is measured by the volatility of sales affects inventory investment based on the accelerator buffer stock inventory model using a panel of dutch listed firms in the period 1984 1996 we find that the estimated coefficient of the speed parameter of adjusting inventories increases vastly when the volatility of sales is used as the proxy for unexpected sales in the stock adjustment equation dutch firms on average overstate future sales leading firms to accumulate inventories partially due to the concern of avoiding stock out in case of highly unexpected demand

bullwhip effect measurement and its implications the bullwhip effect or demand information distortion has been a subject of both theoretical and empirical studies in the operations management literature in this paper we develop a simple set of formulas that describe the traditional bullwhip measure as a combined outcome of several important drivers such as finite capacity batch ordering and seasonality our modeling framework is descriptive in nature as it features certain plausible approximations that are commonly employed in practical inventory systems the results are nonetheless compelling and can be used to explain various conflicting observations in previous empirical studies building on the theoretical framework we discuss the managerial implications of the bullwhip measurement we show that the measurement can be completely noninformative about the underlying supply chain cost performance if it is not linked to the operational details such as decision intervals and leadtimes specifically we show that an aggregated measurement over relatively long time periods can mask the operational level bullwhip in addition we show that masking also exists under product or location aggregation in some illustrative cases

the impact of exchange rates and developing country debt on commodity prices a major feature of the international economy over the past decade has been the swings in the value of the us dollar the dollar fell to a historically low level in the late i970s but rose sharply over the period i982 4 by the beginning of i985 the dollar was generally considered to be over valued by between 2o and 40 since i985 there has been a depreciation of over one third these wide fluctuations in the value of the dollar have had implications for all major traded goods this paper focuses on the effects of changes in the value of the dollar on primary commodity prices and possible interactions between ldc indebtedness and these effects a rise fall in the value of the dollar must be expected to result in a fall rise in dollar commodity prices ridler and yandle i972 proposed a simple comparative static single commodity model to analyse the effects of exchange rate changes on the price of an individual primary commodity they showed that the commodity price change would be given by the change in an appropriately weighted exchange rate index write the price of commodityj as

dynamic pricing in the presence of inventory considerations research overview current practices and future directions the benefits of dynamic pricing methods have long been known in industries such as airlines hotels and electric utilities where the capacity is fixed in the short term and perishable in recent years there has been an increasing adoption of dynamic pricing policies in retail and other industries where the sellers have the ability to store inventory three factors contributed to this phenomenon 1 the increased availability of demand data 2 the ease of changing prices due to new technologies and 3 the availability of decision support tools for analyzing demand data and for dynamic pricing this paper constitutes a review of the literature and current practices in dynamic pricing given its applicability in most markets and its increasing adoption in practice our focus is on dynamic intertemporal pricing in the presence of inventory considerations

can the production smoothing model of inventory behavior be saved the production smoothing model of inventory behavior has a long and venerable history and theoretical foundations that seem very strong yet certain overwhelming facts seem not only to defy explanation within the production smoothing framework but actually to argue that the basic idea of production smoothing is all wrong most prominent among these is the fact that the variance of detrended production exceeds the variance of detrended sales this paper first documents the stylized facts then it derives the production smoothing model rigorously and explains how the model can be amended to make it consistent with the facts finally it reviews the theoretical and empirical evidence and tries to draw some tentative conclusions

a partially observed markov decision process for dynamic pricing in this paper we develop a stylized partially observed markov decision process pomdp framework to study a dynamic pricing problem faced by sellers of fashion like goods we consider a retailer that plans to sell a given stock of items during a finite sales season the objective of the retailer is to dynamically price the product in a way that maximizes expected revenues our model brings together various types of uncertainties about the demand some of which are resolvable through sales observations we develop a rigorous upper bound for the seller s optimal dynamic decision problem and use it to propose an active learning heuristic pricing policy we conduct a numerical study to test the performance of four different heuristic dynamic pricing policies in order to gain insight into several important managerial questions that arise in the context of revenue management