two warehouse partial backlogging inventory models for deteriorating items under inflation abstract in many real life situations the practical experiences reveal that some but not all customers will wait for backlogged items during a shortage period such as for fashionable commodities or high tech products with short product life cycle the longer the waiting time is the smaller the backlogging rate would be according to such phenomenon taking the backlogging rate into account is necessary thus i here extend the models introduced in yang 2004 two warehouse inventory models for deteriorating items with shortages under inflation european journal of operational research 157 2 344 356 to incorporate partial backlogging and then compare the two two warehouse inventory models based on the minimum cost approach the study shows that the optimal solution not only exists but also is unique and model 2 is still less expensive to operate than model 1 if the factors of partial backlogging and inflationary effect are considered finally some numerical examples for illustration are provided and sensitivity analysis on some parameters is made

stochastic production and heterogeneous risk preferences commercial fishers gear choices we present a model of fishers gear choice which allows for heterogeneity both in production technology and risk preferences and apply it on a panel of swedish trawlers stochastic revenue functions are estimated and used to predict the mean and standard deviation of revenue for each trip in a random parameters logit model we test if these predicted values explain gear choice a majority of fishers respond positively to increased mean and negatively to increased variability of expected landing values indicating risk aversion but also show a strong tendency to choose the same gear used on the previous trip

an inverse demand system for new england groundfish welfare analysis of the transition to catch share management the welfare effects of the 2010 transition from days at sea to catch share management in the northeast u s groundfish fishery are examined by combining a model of groundfish demand with a simulation based model of supply counterfactual supply is constructed based on the days at sea system that was recalibrated to meet mandated conservation goals due to the decreases in catch that were required to meet those goals the 2010 policy undoubtedly resulted in worse outcomes for both producers and consumers compared to 2009 however the conservation equivalent days at sea system would have been far worse for both consumers and producers copyright 2013 oxford university press

examining the relationship between stock return volatility and trading volume new evidence from an emerging economy using daily stock return data for individual stocks from an emerging economy this article examines the relationship between return volatility and trading volume under the theoretical postulate of the mixture of distributions hypothesis the results suggest that the contemporaneous trading volume as a proxy for latent information arrival to the market did not contribute to the removal of significant arch or generalized autoregressive conditional heteroscedasticity effects that are found in stocks at the first stage of the investigation the same holds for the lagged volume except for one case this perhaps suggests that the trading volume contemporaneous or lagged is not adequately conveying information to induce traders views of the desirability of trade and therefore points to the need for searching for other micro and macro variables to be used as potential proxy for information arrival to the stock market of the emerging economy

price volatility trading volume and market depth evidence from futures markets the relations between volume volatility and market depth in eight physical and financial futures markets are examined evidence suggests that linking volatility to total volume does not extract all information when volume is partitioned into expected and unexpected components the paper finds that unexpected volume shocks have a larger effect on volatility further the relation is asymmetric the impact of positive unexpected volume shocks on volatility is larger than the impact of negative shocks finally consistent with theories of market depth the study shows large open interest mitigates volatility

an eoq model with partial backordering and advance payments for an evaporating item abstract in the classic economic order quantity model the purchasing cost of an order is paid at the time of its receipt in some cases retailers ask purchasers to pay all or a fraction of the purchasing cost in advance and may allow them to divide the prepayment into several equal sized parts in this paper an economic order quantity model for an evaporating item with partial backordering and partial consecutive prepayments is developed with a real case study of a gasoline station real numerical examples illustrate the proposed model and the solution method

seasonal harvest patterns in multispecies fisheries fishers face multidimensional decisions when to fish what species to target and how much gear to deploy most bioeconomic models assume single species fisheries with perfectly elastic demand and focus on inter seasonal dynamics in real world fisheries vessels hold quotas for multiple species with heterogeneous biological and or market conditions that vary intra seasonally we analyze within season behavior in multispecies fisheries with individual fishing quotas accounting for stock aggregations capacity constraints and downward sloping demand numerical results demonstrate variation in harvest patterns we specifically find 1 harvests for species with downward sloping demand tend to spread out 2 spreading harvest of a high value species can cause lower value species to be harvested earlier in the season and 3 harvest can be unresponsive or even respond negatively to biological aggregation when fishers balance incentives in multispecies settings we test these using panel data from the norwegian multispecies groundfish fishery and find evidence for all three we extend the numerical model to account for transitions to management with individual fishing quotas in multispecies fisheries we show that under some circumstances fishing seasons could contract or spread out

a deterministic order level inventory model for deteriorating items with two storage facilities abstract in this paper a deterministic inventory model is developed for a single deteriorating item which is stored in two different warehouses a rented warehouse is used to store the excess units over the fixed capacity w of the own warehouse the rented warehouse is assumed to charge higher unit holding cost than the own warehouse but to offer a better preserving facility resulting in a lower rate of deterioration for the goods than the own warehouse the optimal stock level for the beginning of the period is found and the model developed is shown to agree with the order level model for non deteriorating items with a single storage facility an illustration to show the applicability of the model is also presented

location choice in new england trawl fisheries old habits die hard in his seminal work on common property resources h scott gordon proposed that in a fishery with multiple grounds effort would be distributed such that profit rates would be equal among them gordon s model relies on implicit assumptions that are inaccurate and lead to false conclusions in many cases in this paper we present an empirically estimated model of fishery and location choice for large trawlers in new england using a random utility framework with a nested logit model specification we use the model to test the validity of a behavioral model developed from ethnographic interviews with skippers

optimal feedback controls comparative evaluation of the cod fisheries in denmark iceland and norway the economic efficiencies of the danish icelandic and norwegian cod fisheries are examined for this purpose nonlinear aggregate models of these fisheries are constructed comparing the calculated optimal harvest and biomass quantities with the actual fisheries provides a measure of the degree of efficiency in these fisheries the comparisons confirm that the cod harvesting policies of these countries have been hugely inefficient in the past it appears that inefficiency has been increasing over the last three to four decades even after tac regulations replaced open access indicating that the management policies adopted by all three countries have failed to cure overfishing the primary purpose of this article is to compare the relative efficiency of past fish harvesting strategies in iceland norway and denmark by the term harvesting policy we mean the harvesting volume each year so efficiency here merely refers to appropriateness of the annual harvesting volumes it does not in particular refer to the relative efficiency of the fishing industries in the three countries we know that maximizing net revenue has not been an objective in any of these fisheries experience shows that the management regimes that were in place for most of the period were highly inefficient and should be expected to produce poor economic results the mere fact that these stocks feature biomass levels far below the maximum sustainable yield level strongly suggests inefficient policies iceland norway and denmark are all major fishing nations harvesting a number of fish species we have chosen to concentrate on cod fishing as this is the single most important fishragnar arnason is professor faculty of economics and business

review of inventory systems with deterioration since 2001 abstract this paper presents an up to date review of the advances made in the field of inventory control of perishable items deteriorating inventory the last extensive review on this topic dates back to 2001 goyal s k and giri b c recent trends in modeling of deteriorating inventory european journal of operational research 134 1 16 since then over two hundred articles on this subject have been published in the major journals on inventory control indicating the need for a new review we use the classification of goyal and giri based on shelf life characteristics and demand characteristics contributions are highlighted by discussing main system characteristics including price discounts backordering or lost sales single or multiple items one or two warehouses single or multi echelon average cost or discounted cash flow and payment delay

intrinsic fish characteristics and intraseason production efficiency a management level bioeconomic analysis of a commercial fishery biological changes in pacific whiting merluccius productus and corresponding production yields were used to model a vertically integrated fishery from harvest through processing the seasonal bioeconomic programming model incorporated stock dynamics with the interactive economic effects of intrinsic fish quality the harvest schedule and quota allocation between heterogeneous user groups the optimal management plan would maximize discounted net industry revenues npv given a minimum spawning biomass npv was maximized when the intraseason timing of harvest coincided with the seasonal improvement in fish quality e g following spawning and or migration npv was only marginally affected however by the quota allocation between groups

allocatable fixed inputs and jointness in agricultural production implications for economic modeling allocatable fixed inputs such as land are a potentially important source of jointness in agriculture as with other causes of jointness they necessitate multiple product systems for modeling product supply and input demand in other important ways however their analytical implications are very different from other causes of jointness model specification differs demand functions for the quantities of each input used in the production of individual commodities can be derived if a primal approach is used but such allocation equations cannot in general be identified from a dual specification available allocation data are not even useful in such dual estimations

dissecting the tragedy a spatial model of behavior in the commons abstract much of the discussion of the tragedy of the commons focuses on aggregate impacts often in data poor developing country settings few non experimental empirical studies shed light on contextual circumstances driving the extent of rent dissipation and overexploitation we utilize a high resolution data set to estimate a behavioral model of fishermen s spatial choices a unique policy setting allows us to measure the degree to which individual fishermen s choices appear aimed at mitigating the tragedy of the commons in a small numbers setting we find evidence of partial mitigation in excess of what we would expect under pure self interest but short of what would occur under group maximizing behavior we also examine how contextual factors in the fishery shape the degree of cooperation within the fishing season and find evidence that competition for the common pool resource distorts fishermen s implicit cost of distance creating a form of common property inertia

liquidity surprise volume and return premia in the oil market abstract we investigate oil market price dynamics in the context of the mixture of distributions hypothesis mdh our econometric model addresses autoregressive properties in returns the impact of surprise volume and conditional oil market return volatility as well as oil market liquidity in the conditional return equation surprise volume as a proxy of private information flow is shown to be unrelated to a set of standard market liquidity proxies oil return heteroscedasticity is found to be partly explained by surprise volume a finding that is consistent with the mdh our findings further show that both oil market liquidity as well as surprise volume shocks are priced in the oil market as such lower levels of lagged market liquidity relate to above average conditional returns surprise volume shocks are associated with lower conditional oil market returns jointly with higher contemporaneous conditional return volatility lagged market liquidity dominates conditional volatility in predicting conditional oil price returns

a deterministic order level inventory model for deteriorating items with two storage facilities abstract sarma 3 developed an inventory model for a single deteriorating item which is stored in two different warehouses an owned warehouse ow and a rented warehouse rw the rented warehouse is used for storing the excess units over the fixed capacity w of the ow and is assumed to offer better preserving facilities than the ow resulting in a lower rate of deterioration also the rw is assumed to charge higher holding cost than the ow in his paper sarma obtained an optimal replenishment schedule when the demand rate is constant over a fixed cycle length where the ow has to stock a specified known quantity in this paper we relax the assumptions of fixed cycle length and known quantity to be stocked in the ow further we find the optimal schedule that minimizes the total cost per unit time in a cycle for an arbitrary demand rate function where cycles are assumed to form a regenerative process we also present numerical examples

arch models properties estimation and testing abstract the aim of this survey paper is to provide an account of some of the important developments in the autoregressive conditional heteroskedasticity arch model since its inception in a seminal paper by engle 1982 this model takes account of many observed properties of asset prices and therefore various interpretations can be attributed to it we start with the basic arch models and discuss their different interpretations arch models have been generalized in different directions to accommodate more and more features of the real world we provide a comprehensive treatment of many of the extensions of the original arch model next we discuss estimation and testing for arch models and note that these models lead to some interesting and unique problems there have been numerous applications and we mention some of these as we present different models the paper includes a glossary of the acronyms for the models we describe

a model of regulated open access resource use abstract this paper develops a model of regulated open access resource exploitation the regulatory model assumes that regulators are goal oriented choosing target harvest levels according to a safe stock concept these harvest quotas are implemented by setting season lengths conditioned on the industry fishing capacity the industry enters until rents are dissipated conditioned on season length regulations harvest levels fishing capacity season length and biomass are determined jointly using parameter estimates from the long regulated north pacific halibut fishery predictions of these variables from the regulated open access model are compared to predictions that arise from the gordon model

the relation between price changes and trading volume a survey this paper reviews previous and current research on the relation between price changes and trading volume in financial markets and makes four contributions first two empiri cal relations are established volume is positively related to the magnitude of the price change and in equity markets to the price change per se second previous theoretical research on the price volume relation is summarized and critiqued and major insights are emphasized third a simple model ofthe price volume relation is proposed that is consis tent with several seemingly unrelated or contradictory observations and fourth several directions for future research are identified

an optimal control of inventory under probablistic replenishment intervals and known price increase abstract the unit purchase price of products may increase or decrease for various reasons which influences the seller s and buyer s inventory control policies this paper develops an inventory control model when replenishment intervals are probabilistic and partial backordering in which an announced price increase happens and the buyer can make a special order before the price increase initiates inventory at the beginning of the period is not equal to zero and can be positive or negative amounts the main aim of this paper is to determine the optimum amount of replenish up to level in special sale offer this model is analyzed in two cases according to the inventory level in which the price increase happens and both cases are formulated to maximize the total saving function for placing a special order or not a closed form solution is obtained for the optimum amount of a special order two special cases with the replenishment intervals following uniform or exponential distributions are studied with sensitivity analysis the results indicate that a buyer can determine the optimal values of the maximum level of inventory and order quantity when the time between two consecutive replenishments is a probabilistic variable and the buyer experiences known price increase for which the total profit is maximized

technological change and the tragedy of the commons the lofoten fishery over 130 years we analyze the effect of technological change on labor and total factor productivity in the lofoten fishery using detailed data for 130 years our findings support the important role of natural resources in productivity and improvements in welfare in natural resource based industries the total factor productivity has risen faster than labor productivity in the fishery indicating that the considerable technological progress in this industry has to some extent been neutralized by the decline in the fish stock open access to the fish resource most probably led to this situation

intra day futures price volatility information effects and variance persistence this paper was prepared for presentation at the conference on nonlinear dynamics and econometrics ucla 5 6 april 1991 under the title information and chronological time effects in intra day futures price volatility the authors are grateful to participants of the nonlinear dynamics conference and to leigh riddick george wang and two anonymous referees for helpful comments the bds program was provided by w d dechert and the bispec program was provided by doug patterson the views stated within are those of the authors and do not necessarily reflect those of the commodity futures trading commission or its staff this paper examines the role of the rate of information arrival proxy variables as they relate to persistence in the variance structure of minute by minute s p 500 index futures returns series the role of contract volume floor transactions the number of price changes executed order imbalance and an information composite in reducing variance persistence is examined all proxy variables are found to explain a significant amount of returns variance while the characteristics of returns data vary daily some evidence of remaining variance persistence is found regardless of the definition of the rate of information arrival variable our results suggest that utilization of a pure arch type model for highfrequency returns data implies a mis specification

planning for shortages net present value analysis for a deteriorating item with partial backlogging abstract this paper develops inventory models to help answer strategic questions concerning whether planning for shortages offers financial benefits a production inventory system producing a deteriorating product in batches at a finite production rate with partial backordering is considered customers pay a deposit when placing a backorder backordered items receive a discount on the sales price as lost sales may lead to customers not returning the demand rate may depend on the fraction of lost sales we develop a cash flow based profit maximising net present value npv model without the inventory cost parameters commonly used in this context unit holding cost unit backorder cost unit deterioration cost and unit lost sales cost the model finds the optimal inventory policy just like npv models that discount the traditional parameters but has the advantage of not needing to estimate the value of the traditional parameters it is shown that in models based on discounting the traditional parameters the parameters are not exogenously determinable but are non trivial functions of non financial endogenous system parameters such as the production rate annual demand rate and backorder rate extensive numerical experiments illustrate how cash flow npv models provide insights into the value of planning for shortages and strategic choices about the design of the production inventory system it also provides insight into the classical problem of how to interpret unit backorder cost and unit lost sales cost the study indicates that these insights cannot be reliably obtained from npv models based on discounting unit backorder costs and unit lost sales costs

a deterministic inventory model for deteriorating items with two warehouses and finite replenishment rate abstract a deterministic inventory model for deteriorating items with two warehouses is developed when the replenishment rate is finite demand is at a uniform rate and shortages are allowed it is assumed that the rates of deterioration of item in the two warehouses may be different the model is analysed for the case of continuous release pattern several special cases are discussed and a numerical example is provided to illustrate the variation in optimum inventory level and optimum cost for varying shortage cost

long run profit functions for multiproduct firms a long run specification of the multiproduct profit function is developed from the restricted profit function the multiproduct restricted profit function and the envelope condition are used to estimate the optimal long run levels of the quasi fixed factor formulas for long run marshallian elasticities of substitution and transformation economies of scope product specific and overall economies of scale and economic measures of capacity utilization are developed for the translog functional form the methodology is illustrated by a case study of the new england otter trawl industry

markets and rent dissipation in regulated open access fisheries abstract using a model of regulated open access resource use with markets we illustrate the potential complexity of interactions between markets product quality excess effort and regulatory behavior in fisheries our model assumes two product types one of which is processed and storable the model describes the equilibrium that results when effort responds to open access incentives and when regulators respond to effort growth by mitigating its potential harmful effects on biomass safety we use numerical simulations to demonstrate a mechanism by which market growth leads to the diversion of raw inputs into the inherently inferior market the result is a scenario in which rents are dissipated not only because excessive inputs raise costs but also because inferior product types reduce revenues we conclude with an illustrative decomposition of rent gains into revenue and cost savings gains from rationalizing a hypothetical fishery demonstrating the potential significance of market side rents

two warehouse partial backlogging inventory models with three parameter weibull distribution deterioration under inflation abstract in many inventory systems the effects of deterioration of physical goods have drawn much attention of various researchers in recent years the more the deterioration is the more the order quantity would be according to such consideration taking the deterioration rate into account is necessary thus in this paper i develop the two warehouse partial backlogging inventory model introduced in yang 2006 to incorporate three parameter weibull deterioration distribution the objective is to derive the optimal replenishment policy that minimizes the net present value of total relevant cost per unit time two alternative models are compared based on the minimum cost approach the study shows that the optimal solution not only exists but also is unique model 2 is still less expensive to operate than model 1 in the proposed model finally some numerical examples and sensitivity analysis on parameters are made to validate the results of the proposed inventory system

the dynamic efficiency costs of common pool resource exploitation we conduct the first empirical investigation of common pool resource users dynamic and strategic behavior at the micro level using real world data fishermen s strategies in a fully dynamic game account for latent resource dynamics and other players actions revealing the profit structure of the fishery we compare the fishermen s actual and socially optimal exploitation paths under a time specific vessel allocation policy and find a sizable dynamic externality individual fishermen respond to other users by exerting effort above the optimal level early in the season congestion is costly instantaneously but is beneficial in the long run because it partially offsets dynamic inefficiencies jel d24 q21 q22

resource rent in individual quota fisheries traditional fisheries management schemes generate incentives for vessels to maximize catch resulting in rent dissipation and overcapacity individual vessel quota management schemes change the incentives to maximize profit and have the potential to generate resource rent and reduce capacity an interesting question is whether it is the changed incentives due to individual quota or the capacity reduction due to transferability of individual quota that is most important in generating rent in this study a cost function approach is used to model and measure rent generated and potential rent in a fishery managed with individual vessel quotas

a survey of deterministic models for the eoq and epq with partial backordering models for the basic deterministic eoq or epq problem with partial backordering or backlogging make all the assumptions of the classic eoq or epq model with full backordering except that only a fraction of the demand during the stockout period is backordered in this survey we review deterministic models that have been developed over the past 40 years that address the basic models and extensions that add other considerations such as pricing perishable or deteriorating inventory time varying or stock dependent demand quantity discounts or multiple warehouses

heteroskedasticity in stock return data volume versus garch effects this paper provides empirical support for the notion that autoregressive conditional heterqskedasticity arch in daily stock return data reflects time dependence in the process generating information flow to the market daily trading volume used as a proxy for information arrival time is shown to have significant explanatory power regarding the variance of daily returns which is an implication of the assumption that daily returns are subordinated to intraday equilibrium returns furthermore arch effects tend to disappear when volume is included in the variance equation the autoregressive conditiqnal heteroskedasticity arch process of engle 1982 has been shown to provide a good fit for many financial return time series 1 arch imposes an autoregressive structure on conditional variance allqwing volatility shocks to persist over time this persistence captures the propensity of returns of like magnitude to clu ter in time and can explain the well documented nonnormality and nonstability of empirical asset return distributions see especially fama 1965 an appealing explanation for the presence of arch is based upon the hypothesis that daily returns are generated by a maiture of distributions in which the rate of daily information arrival is the stochastic mixing variable as suggested by diebold 1986 gallant hsieh and tauchen 1988 and stock 1987 1988 arch might capture the time series properties e g serial correlation of this mixing variable hqwever this linkage has not been broadly documented with the datia the objective of this study is to examine the validity of this explanation for daily stock returns the empirical strategy exploits the implication of the mixture model that the variance of daily price increments is heteroskedastic specifically positively related to the rate of daily information arrival using daily trading volume as a proxy for the mixing variable we show that for a sample of 20 common stocks arch effects vanish when volume is included as an explanatory variable in the conditional variance equation

two warehouse inventory models for deteriorating items with shortages under inflation abstract in this paper the two warehouse inventory problem for deteriorating items with constant demand rate and shortages under inflation is considered in contrast to the traditional deterministic two warehouse inventory model with shortages at the end of each replenishment cycle an alternative model in which each cycle begins with shortages and ends without shortages is proposed here the optimal solution not only exists but also is unique comparing these two two warehouse inventory models the study shows that the proposed model is less expensive to operate than the traditional one in the case of the inflation rate is greater than zero hence under the consideration of inflationary effect the proposed model is less expensive finally some numerical examples for illustration are provided