evaluating jointly constrained order quantity complexities for incremental discounts abstract in this paper we consider the purchasing decisions facing a buying firm which receives incrementally discounted price schedules for a group of items in the presence of constraints such as budgets and space limitations the constraints take the form of upper bounds on positively weighted linear combinations of order size dollar volume unit price and order frequency we adapt the solution procedures from an earlier paper naval res logis 40 2 1993 255 to treat this case the results show that simultaneous order quantities for multiple items offered with separate incremental discounts and subject to joint resource constraints can be calculated efficiently using a combination of lagrangean relaxation and as needed partial enumeration this problem proved to be no more and no less tractable than its counterpart with all units discounts

dynamics of fine wine and asset prices evidence from short and long run co movements this article examines short and long term price linkages among the majority of fine wine and equity markets over the period of 2003 to 2012 we do not consider the price index liv ex 100 or 500 as is typically undertaken in previous studies but rather examine the auction price series of the world s most traded wine vintage pairs 5 bordeaux first growth 8 bordeaux second growth 5 burgundy 3 rhone 4 italian 5 californian 1 australian and 1 portuguese a global equity index is also included using the morgan stanley capital international world cointegration procedures the granger non causality test and ecm are used to analyse short and long run relationships among these markets the results indicate a strong effect of financial markets on wine prices and short term causality for certain wines moreover the findings indicate short run causality between the wines themselves revealing a leader exogenous or follower endogenous status of certain fine wines in price dynamics and also long ru

the impact of multiple stocking points on system profitability in this paper we examine the impact of multiple stocking points on system profitability by examining the increased profit needed to offset cost increases due to cycle inventory safety stock and order placement we utilize the economic order quantity model to analytically evaluate this relationship a table based on the analytical result is presented at the end of the paper that quickly illustrates this relationship

the effect of salaries and opportunity costs on duration in teaching evidence from michigan this paper demonstrates that salaries and opportunity costs have important influences on how long teachers stay in teaching the empirical work is based on a new longitudinal dataset providing information on the careers of 7800 michigan public school teachers the generalized least squares estimation technique accommodates censored observations time varying covariates and fixed effects one implication of the result is that predictions from the current generation of teacher supply and demand models are likely to be misleading copyright 1989 by mit press

a generalized quantity discount pricing model to increase supplier s profits in this paper the joint problem of ordering and offering price discount by a supplier to his sole major buyer is analyzed the objective is to induce the buyer to alter his order schedule and size so that the supplier can benefit from lower set up ordering and inventory holding costs we generalize the quantity discount pricing model of monahan monahan j p 1984 a quantity discount pricing model to increase vendor profits management sci 30 6 720 726 to 1 explicitly incorporate constraints imposed on the amount of discount that can be offered and 2 relax the implicit assumption of a lot for lot or order for order policy adopted by the supplier an algorithm is developed to solve the supplier s joint ordering and price discount problem

competitive and cooperative policies for the vendor buyer system abstract this paper considers a model for decentralized dynamic production distribution control we examine the situation where a vendor produces a product in a batch production environment and supplies it to a buyer under deterministic conditions some conditional games for the vendor and the buyer are defined the games are indexed by numbers of shipments acceptable to both players before the strategies competition begins a construction of nash equilibrium strategies is given in the proof of the existence theorem goyal s numerical example is used to compare our equilibrium solutions with relatively optimal policies in the cooperative case

heterogeneity and fine wine prices application of the quantile regression approach this study addresses the price heterogeneity of the five first growths of bordeaux we apply the quantile regression qr approach with market segmentation based on wine bottle price quantiles we

a dynamic model for the single vendor multi buyer problem abstract we consider a problem of a dynamic production distribution situation for a single product we examine the situation where a vendor produces a product in a batch production environment and supplies it to multiple buyers under deterministic conditions stationarity of buyers demands does not imply stationarity of the demand at the vendor which follows a periodic sequence we consider buyers and the vendor demands as periodic sequences in this case some turnpike policies relative to the class of periodic dynamic parameter problems are recommended some remarks on the existence of planning and forecast horizons are also given

the economics of collective reputation evidence from the wine industry we use original data regarding the array of italian winery coalitions wine denominations to analyze the economics and determinants of collective reputation we first run a cross sectional analysis with 2008 data and the full set of control variables then move to the dynamics of collective reputation with panel data analysis on a 30 year time span 1978 2008 group reputation is history dependent in particular past bad collective behavior increases the probability of being stuck in a bad reputation trap minimum quality standards and effective enforcement are fundamental drivers of group reputation the relationship between group size and collective reputation is non linear free entry may not be optimal due to free riding problems finally institutional signals such as the wine classification system are useful because they can be used by consumers as easily available proxies for information that is much more difficult to acquire

optimal lot sizing integration policy under learning and rework effects in a manufacturer retailer chain abstract most research in economic manufacturing order quantity management assumes that all products are of perfect quality and are produced at a constant production rate one result of this assumption is that the number of units produced in a given period is constant which is not the case in real life most production systems produce items which are of perfect quality along with some that are of imperfect quality defective items as well as the learning effect affect production and inventory costs thereby shaping the performance of the manufacturer retailer chain the present study uses the nash stackelberg and cooperation games to model an imperfect production system to investigate the combined effects of lot sizing size integration the learning effect imperfect production and the rework process on a manufacturer retailer channel this study also demonstrates the optimal properties of the proposed models develops a search algorithm for obtaining optimal solutions and conducts a numerical study to seek structural and quantitative insights into the structure of the proposed models in addition it analyzes the sensitivity of the solutions in relation to the major parameters

the coordinated replenishment dynamic lot sizing problem with quantity discounts abstract in the classical coordinated replenishment dynamic lot sizing problem the primary motivation for coordination is in the presence of the major and minor setup costs in this paper a separate element of coordination made possible by the offer of quantity discounts is considered a mathematical programming formulation for the extended problem under the all units discount price structure and the incremental discount price structure is provided then using variable redefinitions tighter formulations are presented in order to obtain tight lower bounds for reasonable size problems more significantly as the problem is np hard we present an effective polynomial time heuristic procedure for the incremental discount version of the problem that is capable of solving reasonably large size problems computational results for the heuristic procedure are reported in the paper

optimal pricing and inventory control policy with quantity based price differentiation a firm facing price dependent stochastic demand aims to maximize its total expected profit over a planning horizon in addition to the regular unit selling price the firm can utilize quantity discounts to increase sales we refer to this dual pricing strategy as quantity based price differentiation at the beginning of each period the firm needs to make three decisions replenish the inventory set the unit selling price if the unit sales mode is deployed and set the quantity discount price if the quantity sales mode is deployed or the combination of the two modes of sales we identify conditions under which the optimal inventory control policy and selling pricing strategy is well structured remarkably under a utility based demand framework these conditions can be unified by a simple regularity assumption that has long been used in the auction and mechanism design literature moreover sharper structural results are yielded for the optimal selling strategy we also examine the comparative advantag

hedonic price functions and the measurement of preferences the case of swedish wine consumers abstract a hedonic price function for wine is estimated using swedish data 1989 1991 implicit prices for quality attributes are determined not from a regression of variety price on a vector of quality attributes but rather from a regression of quantity sold adjusted for weeks of availability on price and quality attributes such a reduced form is justified by the assumption that prices and attribute contents can be taken as exogenous to the swedish consumer price elasticity is estimated to be about 1 65 holding quality constant showing that swedish consumers are highly sensitive to price estimates of the implicit valuations of quality attributes are shown to differ greatly from those obtained from the more usual hedonic regression with price as the dependent variable

consumer sorting and hedonic valuation of wine attributes exploiting data from a field experiment this article uses a novel experimental approach to measure consumer willingness to pay wtp for wine attributes we invited customers of a local supermarket who had selected a bottle of wine to purchase to participate in a valuation experiment integrating their original wine choice into the experiment each participant evaluated six alternative wines generating a rich set of data on willingness to pay and consumer characteristics the data from the experiment allow us to compare standard shelf price based wine attribute valuation estimates with estimates using wtp data and an increasing amount of information about individual consumers the full model employs individual fixed effects to estimate wtp parameters without bias from consumer sorting or supply side influences our wtp estimates for wine attributes differ markedly from previous attribute value estimates consumers in our sample display clear and stable preferences for wine varieties but less clear preferences for appellations our results suggest caution is needed in using market prices to estimate parameters of the consumer valuation function for product attributes

teacher quality in public and private schools under a voucher system the case of chile chile is unusual in having long term experience with nationwide school vouchers a key criticism of school voucher systems is that they make it easier for private schools to attract better teachers to the detriment of public schools this paper uses longitudinal data from chile to estimate a discrete choice dynamic programming dcdp model of teacher and nonteacher labor supply decisions and to explore how wage policies affect the composition of the teacher labor force in public and private schools in the model individuals first decide whether to get a teaching degree and then choose annually from among five work home sector alternatives empirical results show that private voucher schools attract better teachers than public schools however the existence of the private voucher sector also draws higher productivity individuals into the teaching profession

the pricing of experience goods the example of en primeur wine the market for primeur wine in the bordeaux region allows producers to sell wine that is still in barrels as with all experience goods producers send quality signals to uninformed buyers using original data on bordeaux wines we show that the pricing behavior of producers depends to a large extent on their reputation and much less on short term changes in quality as measured by experts grades we also find that the primeur price has an informative role since a 10 increase in primeur price leads to a 3 increase in prices on the market for bottled wine

prices of american pinot noir wines climate craftsmanship critics pinot noir a variety originating from burgundy in france is the most expensive category of table wine produced in north america this article is aimed at analyzing its price determinants and focuses on climate critical scores and variables related to the winemaker the main findings are as follows 1 pinot noir prices are mainly determined by temperature and precipitation general temperature increases are not beneficial in fact the optimal climate is similar to that in burgundy 2 the second most important variable is the winemaker his or her skill and reputation have a significant impact on prices 3 expert knowledge in the form of critical scores has little explanatory value

a two stage supply chain coordination mechanism considering price sensitive demand and quantity discounts abstract this paper explores the coordination between a supplier and a buyer within a decentralized supply chain through the use of quantity discounts in a game theoretic model within this model the players face inventory and pricing decisions we propose both cooperative and non cooperative approaches considering that the product traded experiences a price sensitive demand in the first case we study the dynamics of the game from the supplier s side as the leader in the negotiation obtaining a stackelberg equilibrium and then show how the payoff of this player could still improve from this point in the second case a cooperative model is formulated where decisions are taken simultaneously emulating a centralized firm showing the benefits of the cooperation between the players we further formulate a pricing game where the buyer is allowed to set different prices to the final customer as a reaction to the supplier s discount decisions for the latter we investigate the difference between feasibility of implementing a retail discount given a current coordination mechanism and without it finally the implications of transportation costs are analyzed in the quantity discount schedule our findings are illustrated with a numerical example showing the difference in the players payoff in each case and the optimal strategies comparing in each case our results with existing work

group buying on the web a comparison of price discovery mechanisms web based group buying mechanisms are being widely used for both business to business b2b and business to consumer b2c transactions we survey currently operational online group buying markets and then study this phenomenon using analytical models we build on the literatures in information economics and operations management in our analytical model of a monopolist offering web based group buying under different kinds of demand uncertainty we derive the monopolist s optimal group buying schedule under varying conditions of heterogeneity in the demand regimes and compare its profits with those that obtain under the more conventional posted price mechanism we further study the impact ofproduction postponement by endogenizing the timing of the pricing and production decisions in a two stage game between the monopolist and buyers our results have implications for firms choice of price discovery mechanisms in e markets and for the scheduling of production and pricing decisions in the presence and absence of scale economies of production

wine market prices and investment under uncertainty an econometric model for bordeaux crus classes this paper describes an econometric assessment of wine market prices for 21 of the crus classes ch teaux in the bordeaux region of france the model developed in the analysis attempt to define the relationship between factors that influence wine quality and those that influence wine prices characteristics of the models are 1 climate influences on grape composition acid and sugar levels 2 grape composition influences on market prices 3 subjective quality evaluations parker points on market prices and 4 the effects of age of the wine on market prices the results indicate that composition levels of merlot dominated wines are more climate sensitive than those from cabernet sauvignon dominated wines overall warm dry summers result in high sugar and low acid levels at harvest which in turn lead to higher quality wines wine market price sensitivity to parker point ratings indicates that properties with high cabernet sauvignon dominated wines are highly dependent on the external ratings while merlot dominated wines have a decreased rating sensitivity smaller properties tend to gain over proportionally from high ratings indicating great jumps in price from year to year additionally ch teaux that have experienced high ratings for past vintages exhibit great sensitivity to point steps in ratings for current vintages aging has a positive effect on bordeaux wine pricing this is due to the increasing maturity as well as the increasing absolute scarcity absolute scarcity of product is expressed by the size of the property with small properties producing less per vintage and therefore having less in the market additionally merlot dominated wines exhibit more maturing potential and profit more from aging than cabernet sauvignon dominated wines average per ch teau real annual profit ranges from 1 to 10 high levels of grape ripeness absolute scarcity and smaller properties that are dominated by merlot in their blend lead to the highest profits forecasts for a vintage not yet on the market indicates that 1995 is better than 1994 for both cabernet sauvignon and merlot dominated wines but that 1996 and 1997 are not as good as 1995 especially for merlot dominated wines 2001 elsevier science b v all rights reserved

predicting the quality and prices of bordeaux wine bordeaux wines have been made in much the same way for centuries this article shows that the variability in the quality and prices of bordeaux vintages is predicted by the weather that created the grapes the price equation provides a measure of the real rate of return to holding wines about 2 3 per annum and implies far greater variability in the early or en primeur wine prices than is observed the analysis provides a useful basis for assessing market inefficiency the effect of climate change on the wine industry and the role of expert opinion in determining wine prices

climate grapevine phenology wine production and prices pauillac 1800 2009 this paper analyzes 19th and 20th century data from a well known chateau in bordeaux the dataset includes information on weather conditions starting dates of three phenological stages of grapevine prices and yields we discuss how these variables have evolved over the last two centuries we also study to what extent the impact of climate on yields and prices has changed over time our regression analysis suggests that the effect of temperature on yields has become weaker since the 19th century the influence on prices has on the contrary become stronger

forecasting bordeaux wine prices using state space methods generic bordeaux red wine basic claret can be regarded as being similar to an agricultural commodity production volumes are substantial they are traded at high frequency and the quality of the

the price of wine abstract using historical price records for bordeaux premiers crus we examine the impact of aging on wine prices and the long term investment performance of fine wine in line with the predictions of an illustrative model young maturing wines from high quality vintages provide the highest financial returns past maturity famous ch teaus deliver growing non pecuniary benefits to their owners using an arithmetic repeat sales regression over 1900 2012 we estimate a real financial return to wine investment net of storage costs of 4 1 which exceeds bonds art and stamps returns to wine and equities are positively correlated finally we find evidence of in sample return predictability

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

a dynamic model of teacher labor supply the labor supply decisions of certified elementary and high school teachers are examined using data from a general longitudinal survey a significant decrease in the teaching participation rate tak

environmental performance impacts of vendor buyer coordination abstract effective coordination is a hallmark of successful supply chain management without such coordination vendors and buyers will act independently to make decisions that optimize their own objectives e g maximize their respective profits or minimize their costs this non coordinated approach is unlikely to be optimal when one considers the supply chain as a whole most vendor buyer coordination research concentrates only on an objective of minimizing total system costs but with the increasing environmental awareness in business and the general public many organizations acknowledge that strategies and practices which incorporate environmental considerations are essential to acquire a competitive advantage the objectives of this research are concerned not only with the economic impact of vendor buyer coordination on the organizations involved but also with the wider effects on society such as the effects of pollution on the environment this research demonstrates how to effectively incorporate environmental issues into vendor buyer coordination first we study the impacts of cost minimizing vendor buyer coordination models on environmental performance when compared with independent non coordinated optimization second we develop a single vendor multi buyer coordination model that includes both costs and environmental performance measures in its objective function a numerical example and a real case study show how both the total system cost and the environmental performance can be simultaneously improved

the influence of classroom characteristics on high school teacher turnover i introduction a number of authors have suggested that the u s will face a shortage of qualified teachers in the near future especially in the areas of math and science 1 school districts facing such a shortage could respond in a variety of ways for instance hiring standards could be lowered teachers could be asked to teach outside their areas of certification or funds permitting starting salaries could be increased in an effort to attract the most promising candidates still another option would be to raise teaching loads i e average class size or the number of classes taught thus making do with fewer teachers this option is particularly alluring in light of the fact that average class size has been falling rapidly in the u s over the last twenty years and yet no strong connection between smaller classes and increased student learning has been established 2 there is however a possible hidden cost that needs to be investigated before recommending such a course of action if teachers respond to larger or more frequent classes by quitting then a district that tries to solve its hiring problems in this fashion could simply be increasing its demand for new teachers this paper uses data from the new york state education department s personnel master file for the years 1979 to 1989 in order to investigate whether an increased teaching load affects the likelihood that a teacher will leave his or her district in order to obtain an unbiased sample of job lengths the sample is restricted to full time high school teachers who were newly hired in 1979 3 we estimate a discrete time hazard model in which teaching load is measured as the average class size taught by an individual the number of classes taught and the proportion of classes taught in the teacher s certified area in interpreting our results we pay special attention to whether the behavior of math and science teachers differs from that of other teachers this is an important issue because shortages of qualified teachers in these two areas are predicted to be especially acute ii background the market for teachers differs from a well functioning neoclassical labor market in that salaries are determined through a political process involving various levels of government the public and often teachers unions 4 if the demand for teachers increases as retirements and student enrollment increase then starting salaries cannot be counted on to quickly move to the market clearing level and thus a shortage of teachers becomes a possibility 5 few observers however believe that there will be an actual shortage of warm bodies the more likely scenario is that there will be a lack of teachers trained in specific areas and of high quality teachers in general see murnane et al 1991 1 2 given a limited budget what are the options available to a school district facing this type of shortage the district could settle for hiring lower quality teachers but this might be seen as an unnecessary measure with long term implications taken in response to what could be a temporary situation another option that has been suggested is to increase teacher workloads 6 whether this option is workable depends in part on the exit decisions of teachers a large number of empirical studies have investigated the determinants of teacher turnover however no work specifically directed toward capturing the effect of increased teaching responsibilities on turnover has been done 7 without knowing whether such an effect exists and what the magnitude of it might be informed policy decisions at the district level in response to a shortage of qualified teachers becomes impossible past studies have shown that the probability of a teacher leaving his or her job is high in the first few years after entering the profession falls after the third year 8 and again increases as the teacher nears retirement age murnane et al

a cooperative inventory policy with deteriorating items for a two echelon model a cooperative inventory policy between supplier and buyer is proposed unlike other studies we consider the case of deteriorating items and permit the completed back order in the problem we solve the problem without the condition of equal replenishments periods during a specified planning horizon and present a procedure to find the optimal solution a case is presented to demonstrate the application of the proposed approach the sensitivity analysis for a cooperation policy between supplier and buyer also are explored

recruiting and retaining teachers in the uk an analysis of graduate occupation choice from the 1960s to the 1990s this paper examines the market for teachers in the uk from 1960 to 2002 using six graduate cohort data sets we find that while there is no strong evidence that teachers are underpaid the relative wages in teaching compared with alternative professions have a significant impact on the likelihood of graduates choosing to teach this wage effect is strongest at times of low relative teachers wages or following a period of decline in those wages it is also strongest for those individuals who have more recently graduated and for men

analysis of supply chains with quantity based fixed incentives abstract this paper examines the use of quantity based fixed incentives to coordinate inventory decisions in a decentralized supply chain we consider a two stage supply chain of autonomous supplier and distributor and prove that the optimal ordering policy for the newsvendor distributor under fixed incentives is an s s type policy we further show that external and internal quantity based incentives can restore channel coordination in single period and channel members can benefit through arbitrary splitting of the resulting additional chain profit the single period results are extended to multiple periods and the impact of fixed incentives on the distributor s optimal stocking policy and channel efficiency are examined under three different multi period supplier strategies numerical examples are used to compare the multi period strategies and to provide additional managerial insights the results show that contrary to common belief incentive plans developed and maintained based only on current inventory data perform poorly in long term and that such incentive plans must be periodically updated to enhance their efficiency furthermore we show that high level of incentives designed to push too much inventory downstream of the supply chain can actually reduce the chain s efficiency

existence of forecast horizons in undiscounted discrete time lot size models we are concerned with a discrete time undiscounted dynamic lot size model in which demand and cost parameters are constant for an initial few periods as our main result we obtain an upper bound on the number of these periods which guarantees the optimality of the economic order quantity eoq as the size of the production lot to be produced in the first period the upper bound is given and the optimality holds for every problem with an horizon not less than the upper bound and for the infinite horizon problem the data beyond the upper bound are allowed to be specified arbitrarily in the context of forecast horizon theory we obtain conditions for a finite forecast horizon to exist in the undiscounted dynamic lot size model furthermore existence results for forecast horizons in an undiscounted optimization problem are obtained for the first time in this paper

compensation policies and teacher decisions a dynamic discrete choice framework with a flexible structure for unobserved heterogeneity is used to model the occupational decisions of individuals who are certified to teach in elementary and secondary schools the model is estimated using data from the national longitudinal study of the high school class of 1972 and is used to examine the effects of possible changes in the compensation policy for teachers

estimation of a hedonic price equation for bordeaux wine does quality matter in this paper the hedonic price technique is applied to bordeaux wine in the hedonic price function we include not only the objective characteristics appearing on the label of the bottle but also the sensory characteristics of the wine our data come from an experimental study in which juries have evaluated and graded a sample of bordeaux wines the estimation of the hedonic price equation shows that the market price is essentially determined by the objective characteristics the estimation of a jury grade equation shows that quality unlike the market price is essentially determined by the sensory characteristics

teacher mobility responses to wage changes evidence from a quasi natural experiment low mobility responses to wage changes imply rents associated with existing employment relationships for example continued employment after a wage cut all else equal reflects rents in the hand of the worker at the outset and symmetrically voluntary quits after a

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