multiperiod sales production decisions under uncertainty abstract this paper studies the behavior of an expected profit maximizing multiperiod firm under uncertainty in output and demand the firm s problem is to determine in each period the level of sales and inventory and the expected output for the coming period the optimal policy is derived in an explicit closed form and is proved to be myopic it is shown that the observed phenomenon of downward price inflexibility can be explained and further specified by using the results of our model

market power in emission permit markets theory and evidence from the eu ets a well known result about market power in emission permit markets is that efficiency can be achieved by full free allocation to the dominant firm i show that this result breaks down when taking the interaction between input and output markets into account even if the dominant firm perceives market power in the permit market alone i then examine the empirical evidence for price manipulation by the ten largest electricity firms during phase i of the eu ets i find that some firms excess allowance holdings are consistent with strategic price manipulation and that they cannot be explained by price speculation or by precautionary purchases to insure against uncertain future emissions my results suggest that market power is likely to be an empirically relevant concern during the early years of emission permit markets

infinite horizon production scheduling in time varying systems under stochastic demand we consider infinite horizon production scheduling under stochastic demand all problem data are allowed to vary across periods including demand distributions costs and revenues a forecast horizon when it exists is a finite problem horizon with the property that the corresponding first period optimal production decision remains optimal regardless of demand and cost projections beyond this horizon thus a forecast horizon allows us to reduce the amount of future data we need to forecast to solve for an optimal first decision for the infinite horizon problem in this paper we establish the existence of a forecast horizon under the assumptions that 1 costs and revenues are time varying linear and 2 demand is never eventually zero a key result for establishing the existence and computation of forecast horizons is the monotonicity and hence convergence of optimal first period policies as the horizon increases of finite horizon versions of the infinite horizon problem a closed form formula is provided for computing a forecast horizon that depends only on the discount factor and uniform upper and lower bounds on demand and unit production and inventory holding costs in particular its value is independent of and determined in advance of forecasting the demand distribution we show that the effect of uncertainty in demand is to increase the forecast horizon associated with a deterministic problem by a constant plus a factor equal to one plus the ratio of these upper to lower bounds on per period demand the associated forecast horizon can be surprisingly short even a few days when the inventory costs are high

market power permit allocation and efficiency in emission permit markets market power in permit markets has been examined in some detail following the seminal work of hahn q j econ 99 4 753 765 1984 but the effect of free allocation on price manipulation with market power in both product and permit market has not been fully addressed i show that in this case the threshold of free allocation above which a dominant firm will set the permit price above its marginal abatement costs is below its optimal emissions in a competitive market and that overall efficiency cannot be achieved by means of permit allocation alone in addition to being of general economic interest this issue is relevant in the context of the eu ets i find that the largest german uk and nordpool power generators received free allowances in excess of the derived threshold conditional on having price setting power in both the electricity and permit markets these firms would have found it profitable to manipulate the permit price upwards despite being net permit buyers

inventories and price inflexibility a firm maximizing expected discounted profits taking account of the actions of its competitors choosing price and output before stochastic demand is known and holding inventories or unfilled orders to accommodate discrepancies between output and demand is shown to respond to a change in demand by changing its output whether the demand change is transitory or permanent but by changing the price it charges only if the demand change is permanent this proposition is shown to be consistent with german data the data are qualitative the empirical analysis uses the multivariate conditional logit model the empirical results are summarized by gamma coefficients

economic incentives to improve water quality in agricultural landscapes some new variations on old ideas agricultural nutrients and other emissions remain a primary source of water quality degradation in much of the nation many such sources are classified as nonpoint sources under the clean water act and are therefore exempt from most federal regulations and enforceable standards in addition many agricultural nonpoint source emissions are difficult to measure and the damages that result from them depend on the amount that is transported to the waterways nutrient runoff particularly nitrogen and phosphorous from intensive row crop agriculture in much of the cornbelt exemplifies these issues both the lack of enforceable standards and the physical characteristics of nutrient fate and transport make the design of efficient policy challenging as witnessed by the lack of significant progress over the last several decades this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item thi this abstract was borrowed from another version of this item

optimal myopic policy for a stochastic inventory problem with fixed and proportional backorder costs in this paper we consider a single product periodic review stochastic demand inventory problem where backorders are allowed and penalized via fixed and proportional backorder costs simultaneously fixed backorder cost associates a one shot penalty with stockout situations whereas proportional backorder cost corresponds to a penalty for each demanded but yet waiting to be satisfied item we discuss the optimality of a myopic base stock policy for the infinite horizon case critical number of the infinite horizon myopic policy i e the base stock level is denoted by s if the initial inventory is below s then the optimal policy is myopic in general i e regardless of the values of model parameters and demand density otherwise the sufficient condition for a myopic optimum requires some restrictions on demand density or parameter values however this sufficient condition is not very restrictive in the sense that it holds immediately for erlang demand density family we also show that the value of s can be computed easily for the case of erlang demand this special case is important since most real life demand densities with coefficient of variation not exceeding unity can well be represented by an erlang density thus the myopic policy may be considered as an approximate solution if the exact policy is intractable finally we comment on a generalization of this study for the case of phase type demands and identify some related research problems which utilize the results presented here

agricultural runoff as a nonpoint externality a theoretical development the purpose of this paper is to develop and explore a theory dealing with an important facet of agricultural runoff problems agricultural runoff is a nonpoint externality with notable implications for both research and policy a nonpoint externality exists whenever the externality contributions of individual economic agents cannot be practically measured by direct monitoring without monitoring regulations on emissions cannot be enforced and charges or subsidies cannot be assessed thus policies which are usually suggested for pollution abatement are not available there is great need for a theoretical base that can adequately capture these facts such a theory yields some important implications even before specific empirical applications the economic problem of agricultural runoff can be separated into three distinct categories first the sediment nutrients and chemicals removed by runoff represent a loss of resources to the individual farmer these costs are borne privately by farmers second if the discount rate of the individual farmer is greater than the social discount rate or if the farmer has a planning horizon which is shorter than society s the farmer will mine the soil resource at a rate which is more depletive than is socially optimal this is a temporal externality a third category involves the conservation of mass physical resources lost by the individual farm must appear elsewhere in the environment in sufficient quantities these resources are pollutants since water is the primary transport media for these resources it is water that is polluted by soil nutrients and agricultural chemicals this spatial externality has been the focus of much research here we intend to develop a theory for these issues to employ it to suggest a revised research methodology and to provide some important conclusions about alternative runoff policies only two of the three categories of agricultural runoff problems involve externalities and only the spatial externality is considered here

point nonpoint effluent trading with spatial heterogeneity potential earnings from permits sales may provide an incentive for farmers to accept water quality regulation we derive optimal adjustments of point nonpoint effluent trading ratios for heterogeneity in marginal environmental damage and degradation retention of the pollutant across locations in a watershed a simulation based on data from the kymi river valley finland indicates that farmers are the greatest suppliers of permits as expected but that gains from trading vary substantially some farmers may become net buyers of permits and thus net losers from regulation the benefits of effluent trading are distributed unevenly among point sources as well copyright 2008 oxford university press

the economics of pollution permit banking in the context of title iv of the 1990 clean air act amendments abstract this paper presents a model of the collective emission permit banking behavior of electricity generating units affected by title iv of the clean air act amendments of 1990 a rigorous treatment of the constraint that pollution permits cannot be borrowed from future allocations is introduced this approach enables an analysis of the impact of future changes in electricity demand regulations and technologies on the present permit price and emissions level the effect of uncertainty on the banking behavior is also explored

a model of intertemporal emission trading banking and borrowing abstract this paper provides a general treatment of emission trading banking and borrowing in an intertemporal continuous time model using optimal control theory the decentralized behavior of firms is shown to lead to the least cost solution attainable under joint cost minimization explicit solutions for the time paths of emissions and permit prices are derived when firms are allowed to both bank and borrow and when firms are only allowed to bank emission permits the policy implications of emission banking and borrowing are discussed

a note on market power in an emission permits market with banking in this paper we investigate the effect of market power on equilibrium path of an emission permits market in which firms can bank current permits for use in later periods in particular we study the market equilibrium for a large potentially dominant firm and competitive fringe with rational expectations we characterize the equilibrium solution for different permits allocations and discuss the large firm s stock holding constraints needed for credible market manipulation

a trading ratio system for trading water pollution discharge permits abstract the fact that water flows to the lowest level uni directionally is a very specific and useful property of water by utilizing this property we design a trading ratio system trs of tradable discharge permits for water pollution control such a trading ratio system has three main characteristics 1 the zonal effluent cap is set by taking into account the water pollutant loads transferred from the upstream zones 2 the trading ratios are set equal to the exogenous transfer coefficients among zones and 3 permits are freely tradable among dischargers according to the trading ratios this paper shows that the trs can take care of the location effect of a discharge and can achieve the predetermined standards of environmental quality at minimum aggregate abatement costs problems with hot spots and free riding can be avoided and the burdens on both dischargers and the environmental authority should be relatively light

optimal policy for a muti product multi period non stationary stochastic production and customization problem abstract this paper is concerned with a multi product multi period non stationary stochastic production and customization problem in which a firm wishes to satisfy multi period stochastic demands for m products the firm produces a generic product that can be customized into the m products the lead time to produce the generic product is one period the generic product can be customized into any of the m products immediately assume that the costs of production customization storage and shortage are linear also assume that the unsatisfied demands for the m products at the firm in each period are lost the objective of the firm is to find a production customization policy that minimizes the expected cost over a planning horizon we obtain the conditions that ensure that a myopic production customization policy is optimal

a dynamic model of duopoly with customer loyalties consider a static game model of duopoly in which price is the strategic variable production is costless capacity is limitless and all sales are made by the low price setter according to some fixed bounded demand function it is well known that in such a model there is a unique cournot bertrand nash equilibrium which involves both sellers setting a price of zero and earning zero l otits neither the model nor the outcome seems to be a good description of reality and many other models have been proposed in the literature as more realistic and for which more interesting strategic conclusions can be reached see for example friedman 2 for a discussion of some of these in this paper i consider a modification of the above model which is motivated by speculations about markets such as that for automobile insurance which are characterized by repeat buying of a homogeneous commodity which is supplied by a few sellers and expenditures on which form a relatively small part of each buyer s budget in any time period if expenditures by each buyer are small or if buyers expect that there is not a great difference between the prices set by different sellers buyers are not likely to expend many resources shopping for the best price or making complicated strategic decisions furthermore the repeat purchase aspect suggests that the seller from whom the buyer previously purchased has a natural advantage if information about price or quality for the entire market is not free the model which i propose here reflects these considerations specifically buyers do not optimize instead they act according to a simple rule of thumb each buyer purchases from the same seller from whom he purchased in the last period unless that seller has raised his price in which case the buyer purchases from the current period low price setter in either case the buyer purchases an amount which is a fixed function of the price he faces independent of time the identity of the seller and history assuming such 69 0022 053 l 82 030069 08 02 00 o

permit banking in emission trading competition arbitrage and linkage abstract several existing or proposed climate policies have considered bankable permits in a cap and trade c t program that covers beyond a single sector e g electric power or allows the program to link to external c t programs in other regions this paper develops a model of permit banking under imperfect competition and imperfect inter temporal arbitrage in which the firms in one dominant sector can exert market power in both product and permit markets while those in other sectors or linked programs are perfectly competitive a simple analytical model is developed to generate contestable hypothesis we further extend the model to account for the physical power system institutional rules and market conditions and then apply it to the pennsylvania jersey maryland pjm market we show that if the dominant firm has market power then the permit price rises at a higher rate than the discount rate contrary to perfectly competitive permit market where the permit price rises at the discount rate following the classic hotelling s rule furthermore under a declining emissions cap system with the permits front loaded in early time periods the dominant firm has an incentive to suppress the permit prices monopsony when buying the permits in early periods and then inflate the permit prices monopoly when selling them in later periods numerical results of the pjm case are consistent with the analytical conclusion

business cycles and emission trading with banking abstract we propose an emission cap adjustment policy for an emission trading system ets that allows banking of allowances for later use and faces business cycle uncertainty the forward looking banking decisions cause a commitment problem with respect to regulator s next period allowance supply decision we tackle the commitment problem by focusing on the markov equilibrium of the policy the equilibrium policy has a surprisingly simple structure combining features from both price and quantity instruments the regulator s ability to choose a new cap for each period does not render banking obsolete but on the contrary makes banking an integral part of the equilibrium policy using data from the eu ets to calibrate the model we solve the markov equilibrium policy for the case of carbon emissions regulation and compare markov policies with and without the possibility to bank allowances a counterfactual analysis of the eu ets during the period of 2009 2013 shows that the optimal markov policy would have led to a steadier allowance price level and a stricter emission regulation than what was actually observed in the eu ets

a partially observable model of decision making by fishermen this paper presents an application of a partially observable markov decision process for the intraseasonal decisions of fishing vessel operators throughout each fishing season independent vessel operators must decide in which zone or fishing ground of the fishery to fish during each period to catch the most fish with the highest return to fishing effort fishermen s decisions are assumed to be made to maximize net operating income the decision model incorporates the potential fish catch the cost of the fishing effort and the unit price of fish catch potential is modeled by considering the abundance of the fish stock and the catchability of the fishing technique abundance dynamics not observed directly are modeled as a markov chain with a parsimonious state space representation which renders the problem practicable dynamic decision policies are computed by the method of optimal control of the process over a finite horizon the resultant policies are used to simulate distributions of fishermen s ne

optimal replenishment for a periodic review inventory system with two supply modes abstract in this paper we study periodic inventory systems with long review periods we develop dynamic programming models for these systems in which regular orders as well as emergency orders can be placed periodically we identify two cases depending on whether or not a fixed cost for placing an emergency order is present we show that if the emergency supply mode can be used there exists a critical inventory level such that if the inventory position at a review epoch falls below this critical level an emergency order is placed we also develop simple procedures for computing the optimal policy parameters in all cases the optimal order up to level is obtained by solving a myopic cost function thus the proposed ordering policies are easy to implement

emission permit banking pollution abatement and production inventory control of the firm abstract in this paper we present a dynamic model modified with emission permit banking and pollution abatement and investigate the effect of emission permit banking and pollution abatement on the production inventory strategy of the firm after introducing emission permit banking and pollution abatement the cost function consists of the inventory holding and production costs the cost of investment in abatement capital goods and the emission procurement selling cost furthermore the inventory holding costs are linear production costs are non decreasing and convex functions of the production level and the costs of investment in abatement capital goods are increasing and convex functions of the investment level we compare the optimal production inventory strategy before emission permit banking and pollution abatement and thereafter the mathematical investigation is based on the arrow karlin model

market power and transferable property rights the appeal of using markets as a means of allocating scarce resources stems in large part from the assumption that a market will approximate the competitive ideal when competition is not a foregone conclusion the question naturally arises as to how a firm might manipulate the market to its own advantage this paper analyzes the issue of market power in the context of markets for transferable property rights first a model is developed that explains how a single firm with market power might exercise its influence this is followed by an examination of the model in the context of a particular policy problem the control of particulate sulfates in the los angeles region

intertemporal emission trading with a dominant agent how does a restriction on borrowing affect efficiency in this paper we analyze how restricting intertemporal trading by prohibiting borrowing of emissions permits affects the ability of a dominant agent to exploit its market power we show that the monopolist could take advantage of the constraint on borrowing by not distributing the sale of permits cost effectively across periods furthermore we show that a constant present value price over time does not imply a cost effective distribution of abatement permit sales across periods

stopped myopic policies in some inventory models with generalized demand processes this paper considers single item inventory systems with immediate delivery and no economies of scale bounds are provided on the value loss relative to optimal cost for restricting attention to the class of inventory stocking policies that behave myopically up to a specified stopping time the stopping time may be random and may depend on demand histories as well as information exogenous to the firm the bounds are robust to the nature of the demand process faced after the stopping time so are applicable when the statistics of demand after the stopping time are unknown stopping times that are large with high probability imply that near term decisions are completely specified with high probability the general bounding results allow one to consider demand processes that may otherwise be analytically intractable it is shown that the class of demand models for which the assumption of additive i i d shocks is appropriate is the same class admitting effective myopic stocking policies the bounds also make rigorous the intuitive notion that myopic policies are least effective in systems with precipitous drops in demand coupled with an inability to recover cash invested in inventory the option of selling inventory at discount is a reality in many real systems and enhances the attractiveness of the myopic stocking policy in numerical examples the myopic policy is shown to be an effective competitor in a range of systems for which optimal policies are not known the results suggest that for systems with immediate delivery no economies of scale and no currently known optimal policy the myopic stocking rule is a reasonable default policy to adopt

the effect of emission permit trading with banking on firm s production inventory strategies abstract we investigate the effect of tradable emission permits with banking on the production inventory strategy of a firm in this paper the basis of the work is the well known arrow karlin dynamic production inventory model in which the inventory holding costs are linear and production costs are non decreasing and convex functions of the production level the cost of environmental protection is taken into account in the model we assume there is an emission trading program with which firms are able to purchase their emission rights or sell them and the rights are allowed to be deposited in intertemporal trading we compare the optimal production inventory strategies of this paper with those without emission permits

myopic solutions of markov decision processes and stochastic games sufficient conditions are presented for a markov decision process to have a myopic optimum and for a stochastic game to possess a myopic equilibrium point an optimum or an equilibrium point is said to be myopic if it can be deduced from an optimum or an equilibrium point of a static optimization problem or a static nash game the principal conditions are a each single period reward is the sum of terms due to the current state and action b each transition probability depends on the action taken but not on the state from which the transition occurs and c an appropriate static optimum or equilibrium point is ad infinitum repeatable these conditions are satisfied by several dynamic oligopoly models and numerous markov decision processes

myopic solutions to affine dynamic models new sufficient conditions are presented for a dynamic process to have a myopic optimum and for a sequential game to possess a myopic equilibrium point an optimum or an equilibrium point is said to be myopic if it can be specified by solving a static optimization problem or a static nash game the results are applied to an aquaculture harvesting model and a dynamic oligopoly model with advertising decisions

managing inventory with multiple products lags in delivery resource constraints and lost sales a mathematical programming approach this paper develops an order up tos inventory model that is designed to handle multiple items resource constraints lags in delivery and lost sales without sacrificing computational simplicity mild conditions are shown to ensure that the expected average holding cost and the expected average shortage cost are separable convex functions of the order up to levels we develop nonparametric estimates of these costs and use them in conjunction with linear programming to produce what is termed the lp policy the lp policy has two major advantages over traditional methods first it can be computed in complex environments such as the one described above and second it does not require an explicit functional form of demand something that is difficult to specify accurately in practice in two numerical experiments designed so that optimal policies could be computed the lp policy fared well differing from the optimal profit by an average of 2 20 and 1 84 respectively these results compare quite favorably with the errors incurred in traditional methods when a correctly specified distribution uses estimated parameters our findings support the effectiveness of this mathematical programming technique for approximating complex real world inventory control problems

myopic policies for some inventory models with uncertain demand distributions the majority of papers on stochastic inventory theory make the assumption that the distribution of consumer demand in each time period is known with certainty while this assumption is unsupported in many applied contexts it is conventionally held that more realistic models are more difficult to solve and will not yield simple operational policies this paper shows that a simple inventory policy based upon a critical fractile can be optimal or near optimal in some inventory models with parameter adaptive demand processes in these some parameter of the demand distribution is not known with certainty and estimates of the parameter are updated in a statistical fashion as demand is observed through time examples include exponentially smoothed forecasts and bayesian updating of parameter estimates bounds on the value loss relative to optimal cost when using the critical fractile policy can be calculated directly from the problem data some numerical examples illustrate the technique

banking and back loading emission permits in this article we focus on the so called back loading policy adopted by the european commission to increase the carbon market price this environmental measure consists of removing a share of the allowances allocated for a given period in order to reallocate some or all of them later on to analyze the impact of the permits back loading we determine the co2 price equilibrium with and without the policy measure considering not only the market for permits but also the output market of regulated sectors we propose a two period model where the market for permits is perfectly competitive and the output market can be either competitive or oligopolistic first we define the condition under which banking from one period to another is optimal this condition that is the absence of arbitrage opportunities aoa depends not only from the period initial allocation but also on production market fundamentals when this condition is satisfied the market for emission is shown intertemporally efficient second we point out that the back loading measure may create inefficiencies or leave unaffected the permits price if it alters the aoa