analzying trade offs between machine investment and utilization analyzing machine investment opportunities from a systems perspective requires an understanding of interdependencies between machine investment and utilization decisions machine investment decisions involve determining the number of machines to purchase and their types machine utilization decisions involve determining part allocations and production cycles interdependencies between these decisions result in trade offs between investment and operating costs this paper develops an analytical approach for studying machine investment opportunities in a broad systems context it begins with a discussion of the interdependencies between investment and utilization decisions the focus of this research and a review of existing literature related to machine investment decisions are then discussed next a mathematical model that quantifies these interdependencies is formulated the paper ends with a simple example that demonstrates the usefulness of the model and highlights the importance of using a systems app

operating flexibility global manufacturing and the option value of a multinational network the multinational corporation is a network of activities located in different countries the value of this network derives from the opportunity to benefit from uncertainty through the coordination of subsidiaries which are geographically dispersed we model this coordination as the operating flexibility to shift production between two manufacturing plants located in different countries a stochastic dynamic programming model treats explicitly this flexibility as equivalent to owning an option the value of which is dependent upon the real exchange rate the model is extended to analyze hysteresis effects and within country growth options we show that the management of across border coordination has led to changes in the heuristic rules used for performance evaluation and transfer pricing

optimal flexibility configurations in newsvendor networks going beyond chaining and pairing we study the classical problem of capacity and flexible technology selection with a newsvendor network model of resource portfolio investment the resources differ by their level of flexibility where level k flexibility refers to the ability to process k different product types we present an exact set theoretic methodology to analyze newsvendor networks with multiple products and parallel resources this simple approach is sufficiently powerful to prove that i flexibility exhibits decreasing returns and ii the optimal portfolio will invest in at most two adjacent levels of flexibility in symmetric systems and to characterize iii the optimal flexibility configuration for asymmetric systems as well the optimal flexibility configuration can serve as a theoretical performance benchmark for other configurations suggested in the literature for example although chaining is not optimal in our setting the gap is small and the inclusion of scale economies quickly favors chaining over pairing we also demonstrate how this methodology can be applied to other settings such as product substitution and queuing systems with parameter uncertainty

global dynamics in a model with search and matching in labor and capital markets abstract in this paper global macroeconomic dynamics are studied when search frictions are present in both labor and capital markets on the basis of the merz 1995 macroeconomic model with labor market frictions and capital accumulation our paper offers an extension to frictions in capital markets analogously modeled as a search and matching process using the merz model as limit case we consider exogenous as well as endogenous borrowing constraints we also allow the cost of issuing bonds to change endogenously as we show capital market frictions exacerbate and accentuate the interaction between the two markets and magnify the effects of shocks on output consumption employment and welfare this interaction of the frictions in labor and capital markets are also shown to give rise to multiple equilibria on the basis of numerical solution techniques instead of relying on first or second order approximations around a unique steady state our paper uses dynamic programming techniques to compute decision variables and the value function directly and assess the local and global dynamics of the model the steady state solutions are studied by using the hamiltonian and the dynamics are assessed for various model variants by using dynamic programming techniques

flexibility and uncertainty the preserving of flexibility when faced with uncertainty is a neglected aspect of behaviour under risk yet it is an important factor in decisions to hold liquid assets or delay irreversible investment this paper formalizes the notion of flexibility in a sequential decision context and relates its value to the amount of information an agent expects to receive a rudimentary money demand model is developed embodying these ideas and the history of flexibility as an economic concept is traced choices are frequently made between alternatives that imply different degrees of future commitment between a short term investment that leaves future options open for example and a long term one that by its very nature forecloses those options the relative attractiveness of the two depends on their probability distributions of payoffs over time a basic consideration in this choice is the recognition that beliefs about the risks governing these payoffs may change current doubts may be partially resolved in the near future this prospect decreases the attractiveness of the longer term commitment in that one is able to respond less fully to new information and even if it does not directly affect the risks associated with shorter term choices enhances their appeal this paper formalizes the above remarks by establishing connections between the following two partial orderings the first is an ordering based on variability of beliefs one set of beliefs is more variable than another if more final risk is resolved at an intermediate stage the more one expects to learn by an intermediate period relative to what one knows today the more variation one is anticipating in beliefs about the final outcome the second is an ordering of current actions or positions based on flexibility one position is more flexible than another if it leaves available a larger set of future positions at any given level of cost these two orderings are incorporated in a simple sequential decision model to suggest the following behavioural principle the more variable are a decision maker s beliefs the more flexible is the position he will choose this principle potentially applies whenever i there will be opportunities to act after further information is received and ii current actions influence either the attractiveness or availability of different future actions

the optimal mix of flexible and dedicated manufacturing capacities hedging against demand uncertainty abstract a firm that faces uncertain demands for several product groups needs to decide how much of relatively inexpensive dedicated capacity and how much of more expensive flexible capacity to acquire we model this situation as a two stage decision problem investment and allocation we pay particular attention to the dependence of acquisition policy on existing capacities as most firms facing the problem are not likely to be entirely new we show that if initial capacities are lower than the levels that would be optimal in absence of initial capacities the investment decision is a simple acquire up to optimal levels for each capacity type however if some initial capacity is too high the optimal additions to others depend on its value in a non linear yet intuitive fashion we also pose the issue of choosing the degree of flexibility as the realized product mix will affect the performance of partially flexible machines

allocation of flexible and indivisible resources with decision postponement and demand learning we consider a firm that uses two perishable resources to satisfy two demand types resources are flexible such that each resource can be used to satisfy either demand type resources are also indivisible such that the entire resource must be allocated to the same demand type this type of resource flexibility can be found in different applications such as movie theater complexes cruise lines and airlines in our model customers arrive according to independent poisson processes but the arrival rates are uncertain thus the manager can learn about customer arrival rates from earlier demand figures and potentially increase the sales by postponing the resource allocation decision we consider two settings and derive the optimal resource allocation policy for one setting and develop a heuristic policy for the other our analysis provides managerial insights into the effectiveness of different resource allocation mechanisms for flexible and indivisible resources

the real consequences of financial stress abstract we introduce a dynamic banking macro model which abstains from conventional mean reversion assumptions and in which similar to brunnermeier and sannikov 2010 adverse asset price movements and their impact on risk premia and credit spreads can induce instabilities in the banking sector to assess such phenomena empirically we employ a multi regime vector autoregression mrvar approach rather than conventional linear vector autoregressions we conduct bivariate empirical analyses using country specific financial stress indices and industrial production for the u s the uk and the four large euro area countries our mrvar based impulse response studies demonstrate that compared to a linear specification response profiles are dependent on the current state of the economy as well as the sign and size of shocks previous multi regime based studies focusing solely on the regime dependence of responses conclude that during a high stress period stress increasing shocks have more dramatic consequences for economic activity than during low stress conducting size dependent response analysis we find that this holds only for small shocks and reverses when shocks become sufficiently large to induce immediate regime switches our findings also suggest that in states of high financial stress large negative shocks to financial stress have sizeable positive effects on real activity and support the idea of unconventional monetary policy measures in cases of extreme financial stress

supply capacity acquisition and allocation with uncertain customer demands we study a class of capacity acquisition and assignment problems with stochastic customer demands often found in operations planning contexts in this setting a supplier utilizes a set of distinct facilities to satisfy the demands of different customers or markets our model simultaneously assigns customers to each facility and determines the best capacity level to operate or install at each facility we propose a branch and price solution approach for this new class of stochastic assignment and capacity planning problems for problem instances in which capacity levels must fall between some pre specified limits we offer a tailored solution approach that reduces solution time by nearly 80 over an alternative approach using a combination of commercial nonlinear optimization solvers we have also developed a heuristic solution approach that consistently provides optimal or near optimal solutions where solutions within 0 01 of optimality are found on average without requiring a nonlinear optimization solver

volume flexibility in services the costs and benefits of flexible labor resources organizations can create volume flexibility the ability to increase capacity up or down to meet demand for a single service through the use of flexible labor resources e g part time and temporary workers as compared to full time workers although organizations are increasingly using these resources the relationship between flexible labor resources and financial performance has not been examined empirically in the service setting we use two years of archival data from 445 stores of a large retailer to study this relationship we hypothesize and find that increasing the labor mix of temporary or part time workers shows an inverted u shaped relationship with sales and profit while temporary labor mix has a u shaped relationship with expenses thus although flexible labor resources can create volume flexibility for a firm along multiple dimensions it is possible to have too much of a good thing this paper was accepted by serguei netessine operations management

a real options approach to labour shifts planning under different service level targets abstract firms that experience uncertainty in demand as well as challenging service levels face among other things the problem of managing employee shift numbers decisions regarding shift numbers often involve significant expansions or reductions in capacity in response to changes in demand in this paper we quantify the impact of treating shifts in workforce expansion as investments while considering required service level improvements the decision to increase shifts whether by employing temporary workers or hiring permanent employees is one that involves significant risks traditional theories typically consider reversible investments and thus do not capture the idiosyncrasies involved in shift management in which costs are not fully reversible in our study by using real options theory we quantify managers ability to consider this irreversibility aiming to enable them to make shift decisions under conditions of uncertainty with the maximum level of flexibility our model aims to help managers make more accurate decisions with regard to shift expansion under service level targets and to defer commitment until future uncertainties can be at least partially resolved overall our investigation contributes to studies on the time required to introduce labour shift changes while keeping the value of service level improvements in mind

liquidity flows and fragility of business enterprises abstract this paper develops a macroeconomic model in which funds are channeled to entrepreneurs through long term relationships between entrepreneurs and lenders the flow of funds to a relationship may be low causing it to break up due to insufficient liquidity multiple pareto ranked steady states emerge from complementarity between financial intermediation reflected by the number of relationships and households incentives to provide funds this complementarity also serves as a mechanism for propagating aggregate shocks financial collapse may become inescapable if a shock destroys sufficiently many relationships

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

dynamic capacity management with substitution we examine a multiperiod capacity allocation model with upgrading there are multiple product types corresponding to multiple classes of demand and the firm purchases capacity of each product before the first period within each period after demand arrives products are allocated to customers customers who arrive to find that their product has been depleted can be upgraded by at most one level we show that the optimal allocation policy is a simple two step algorithm first use any available capacity to satisfy same class demand and then upgrade customers until capacity reaches a protection limit so that in the second step the higher level capacity is rationed we show that these results hold both when all capacity is salvaged at the end of the last demand period as well as when capacity can be replenished in the latter case an order up to policy is optimal for replenishment although finding the optimal protection limits is computationally intensive we describe bounds for the optimal protection limits that take little effort to compute and can be used to effectively solve large problems using these heuristics we examine numerically the relative value of strictly optimal capacity and dynamic rationing the value of perfect demand information and the impact of demand and economic parameters on the value of optimal substitution

estimating the reduction in labor hours due to a new technology under uncertain demand abstract when investing in a new machine one must estimate the reduced labor costs in the past this was usually done in a deterministic way assuming that we have accurate point estimation of demand rates and the reduction in labor costs is proportional to the reduction in labor hours however if demand rates of products are known probabilistically the expected reduction in labor hours follows a probability distribution this distribution not just the mean value is important because 1 it shows the effect of the uncertainty in demand on estimating the reduction in labor hours and 2 it allows better estimation of labor cost savings when labor costs are not proportional to labor hours using the distribution of product demand rates this paper presents a procedure for estimating the distribution of reduction in labor hours obtained from a new machine

regime dependence of the fiscal multiplier abstract after the financial market meltdown of the years 2007 2008 the obama administration responded with large fiscal stimulus package yet the reaction to this stimulus has been diverse some predicted a multiplier effect in the order of 1 5 others argued that the multiplier will be less than 0 5 such multiplier estimates typically stem from estimated linear vector autoregressions vars or linearized versions of dsge models in this paper we argue that neither conventional var analysis nor linearized dgse models may be appropriate to evaluate demand effects arising from such a stimulus package the reason is as recent research suggests that the timing of demand shocks matters to assess the multiplier s variability we adopt a regime dependent var approach as is shown in detail our model specification is grounded on theoretical considerations the empirical analysis presented here suggests that a regime dependent var specification is favored for u s output and employment data and that the standard one regime var methodology is inappropriate for analyzing multi regime processes although we employ a nonlinear var framework the chosen setup allows the use of largely familiar macroeconometric modeling tools estimating a two regime var we show that the fiscal multiplier varies with the state of the business cycle and the particular specifics of the measure taken for the u s we find for example the fiscal expansion multiplier is much higher in a regime of a low economic activity than in a regime of high activity as we also show it is size dependent

flexible capacity strategy with multiple market periods under demand uncertainty and investment constraint abstract we establish a flexible capacity strategy model with multiple market periods under demand uncertainty and investment constraints in the model a firm makes its capacity decision under a financial budget constraint at the beginning of the planning horizon which embraces n market periods in each market period the firm goes through three decision making stages the safety production stage the additional production stage and the optimal sales stage we formulate the problem and obtain the optimal capacity the optimal safety production the optimal additional production and the optimal sales of each market period under different situations we find that there are two thresholds for the unit capacity cost when the capacity cost is very low the optimal capacity is determined by its financial budget when the capacity cost is very high the firm keeps its optimal capacity at its safety production level and when the cost is in between of the two thresholds the optimal capacity is determined by the capacity cost the number of market periods and the unit cost of additional production further we explore the endogenous safety production level we verify the conditions under which the firm has different optimal safety production levels finally we prove that the firm can benefit from the investment only when the designed planning horizon is longer than a threshold moreover we also derive the formulae for the above three thresholds

inventory pooling under heavy tailed demand risk pooling has been studied extensively in the operations management literature as the basic driver behind strategies such as transshipment manufacturing flexibility component commonality and drop shipping this paper explores the benefit of risk pooling in the context of inventory management using the canonical model first studied in eppen eppen gd 1979 effects of centralization on expected costs in a multi location newsboy problem management sci 25 5 498 501 specifically we consider a single period multilocation newsvendor model where n different locations face independent and identically distributed demands and linear holding and backorder costs we show that eppen s celebrated result i e that the expected cost savings from centralized inventory management scale with the square root of the number of locations depends critically on the light tailed nature of the demand uncertainty in particular we establish that the benefit from pooling relative to the decentralized case in term

vertical flexibility in supply chains jordan and graves jordan w c s c graves 1995 principles on the benefits of manufacturing process flexibility management sci 41 4 577 594 initiated a stream of research on supply chain flexibility which was furthered by graves and tomlin graves s c b t tomlin 2003 process flexibility in supply chains management sci 49 7 907 919 that examined various structures for achieving horizontal flexibility within a single level of a supply chain in this paper we extend the theory of supply chain flexibility by considering placement of vertical flexibility across multiple stages in a supply chain specifically we consider two types of flexibility logistics flexibility and process flexibility and examine how demand production and supply variability at a single stage impacts the best stage in the supply chain for each type of flexibility under the assumptions that margins are the same regardless of flexibility location capacity investment costs are the same within and across stages a

competition under capacitated dynamic lot sizing with capacity acquisition lot sizing and capacity planning are important supply chain decisions and competition and cooperation affect the performance of these decisions in this paper we look into the dynamic lot sizing and resource competition problem of an industry consisting of multiple firms a capacity competition model combining the complexity of time varying demand with cost functions and economies os scale arising from dynamic lot sizing costs is developed each firm can replenish inventory at the beginning of each period in a finite planning horizon fixed as well as variable production costs incur for each production setup along with inventory carrying costs the individual production lots of each firm are limited by a constant capacity restriction which is purchased up front for the planning horizon the capacity can be purchased from a spot market and the capacity acquisition cost fluctuates with the total capacity demand of all the competing firms we solve the competition model and establish the existence of a capacity equilibrium over the firms and the associated optimal dynamic lot sizing plan for each firm under mild conditions

competitive incentives for manufacturing flexibility abstract a game theoretic model is used in this paper to analyze firms incentives to acquire product flexibility the degree of product flexibility is determined by the cost a firm must incur to produce a new product the model helps to identify characteristics of industries which are likely to encourage product flexibility strategies the model suggests that firms in industries where the ratio of price to variable cost is high are likely to expend more effort to increase product flexibility this hypothesis is then tested empirically

optimal investment strategies for flexible resources considering pricing and correlated demands we study the optimal resource investment decision faced by a two product price setting firm that operates in a monopolistic setting and employs a postponed pricing scheme the firm has the option to invest in dedicated resources as well as a more expensive flexible resource that can satisfy both products while the resource investment decision is made under demand uncertainty pricing and resource allocation decisions are postponed to the time when demand curves are realized our analysis provides the structure of the firm s optimal resource investment strategy as a function of demand parameters and investment costs and shows that the flexible resource investment decision follows athreshold policy we also show that it can be optimal for the firm to invest in the flexible resource even when demand patterns are perfectly positively correlated the reason for flexible capacity investment in this case is financial rather than risk pooling on the other hand we show that it can be optimal for the firm not to invest in the flexible resource even when demand patterns are perfectly negatively correlated the flexible resource investment decision in this case depends on the profitability of the two products based on our analysis we provide principles on the firm s optimal resource investment decision

resource flexibility with responsive pricing this article studies two types of flexibility used by firms to better respond to uncertain market conditions resource flexibility and responsive pricing we consider a situation in which a single flexible resource can be used to satisfy two distinct demand classes while the resource capacity must be decided based on uncertain demand functions the resource allocation as well as the pricing decision are made based on the realized demand functions we characterize the effects of two key drivers of flexibility demand variability and demand correlation assuming normally distributed demand curve intercepts demand variability creates opportunity costs and with fixed prices decreases the firm s profit we show that with the additional flexibility gained from responsive pricing the firm can maximize the benefits of favorable demand conditions and mitigate the effects of poor demand conditions ultimately profiting from variability positive demand correlation on the other hand remains undesirable under responsive pricing the optimal capacity of the flexible resource is always increasing in both demand variability and demand correlation this contrasts with the scenarios based on fixed prices highlighting the crucial difference that responsive pricing makes in the management of flexible resources we further quantify the value of flexibility for the firm and its customers by considering as a benchmark a firm relying on two dedicated resources the value of flexibility is most significant if the demand levels are highly variable and negatively correlated in such cases the firm benefits from demand variability due to responsive pricing while facing limited demand risk due to resource flexibility finally we endogenize the input price of the flexible resource by considering the pricing decision of the resource supplier

meta data envelopment analysis finding a direction towards marginal profit maximization abstract this paper discusses a new meta dea approach to solve the problem of choosing direction vectors when estimating the directional distance function the proposed model emphasizes finding the direction for productivity improvement rather than estimating the score of efficiency focusing on planning over evaluation in fact the direction towards marginal profit maximization implies a step by step improvement and wait and see decision process which is more consistent with the practical decision making process an empirical study of u s coal fired power plants operating in 2011 validates the proposed model the results show that the efficiency measure using the proposed direction is consistent with all other indices with the exception of the direction towards the profit maximized benchmark we conclude that the marginal profit maximization is a useful guide for determining direction in the directional distance function

the impact of budget constraints on flexible vs dedicated technology choice this paper studies the flexible versus dedicated technology choice and capacity investment decisions of a multiproduct firm under demand uncertainty in the presence of budget constraints the firm operates under a capital budget for financing the capacity investment and an operating budget which is uncertain in the capacity investment stage for financing the production we investigate how the tightening of the capital budget and a lower financial flexibility in the production stage the likelihood of having a sufficient operating budget shape the optimal technology choice we find that the dominant regime is one where dedicated technology should be adopted for a larger investment cost range and thus is the best response to the tighter capital budget whereas flexible technology is the best response to lower financial flexibility we identify the key roles that the capacity intensity the ratio of unit capacity cost to total unit capacity and production cost of each technology and the pooling value

real wage rigidities and the new keynesian model most central banks perceive a trade off between stabilizing inflation and stabilizing the gap between output and desired output however the standard new keynesian framework implies no such trade off in that framework stabilizing inflation is equivalent to stabilizing the welfare relevant output gap in this paper we argue that this property of the new keynesian framework which we call the divine coincidence is due to a special feature of the model the absence of nontrivial real imperfections we focus on one such real imperfection namely real wage rigidities when the baseline new keynesian model is extended to allow for real wage rigidities the divine coincidence disappears and central banks indeed face a trade off between stabilizing inflation and stabilizing the welfare relevant output gap we show that not only does the extended model have more realistic normative implications but it also has appealing positive properties in particular it provides a natural interpretation for the dynamic inflation unemployment relation found in the data

fair inequality attitudes toward pay differentials the united states in comparative perspective are american attitudes toward economic inequality different from those in other countries one tradition in sociology suggests american exceptionalism while another argues for convergence across

equilibrium unemployment job flows and inflation dynamics this paper develops a general equilibrium model to explain a set of facts regarding job flows unemployment and inflation dynamics it integrates a theory of equilibrium unemployment into a monetary model with nominal price rigidities the labor market displays matching frictions and endogenous job destruction the model can explain the cyclical behavior of unemployment job creation job destruction and the joint fluctuations of the labor input along both the extensive and the intensive margin conditional on a shock to monetary policy allowing for variation of the labor input at the extensive margin leads to a significantly lower elasticity of marginal costs with respect to output this helps to explain the sluggishness of inflation and the persistence of output after a monetary policy shock

contingent labor contracting under demand and supply uncertainty firms increasingly use contingent labor to flexibly respond to demand in many environments labor supply agencies are growing to fill this need as a result firms and agencies are engaging in long term contracts for labor supply we develop mathematical models of the interaction between firms and labor supply agencies when demand and supply are uncertain we consider two models of labor supply uncertainty termed productivity and availability uncertainty and study how each affects the nature of the contracts formed these models reflect two major roles played by the labor supply agency in the case of productivity uncertainty we find that it is possible to construct a contract that coordinates the firm and agency hiring in an optimal way in contrast we show that in environments characterized by availability uncertainty optimal contracts are not possible however there is a large range of contract parameters for which both parties would benefit from a contract we analyze these and discuss the trade offs that should be considered in contract negotiation

efficient supply contracts for fashion goods with forecast updating and two production modes we examine the problem of developing supply contracts that encourage proper coordination of forecast information and production decisions between a manufacturer and distributor of high fashion seasonal products operating in a two mode production environment the first production mode is relatively cheap but requires a long lead time while the second is expensive but offers quick turnaround we focus on contracts of the form w1 w2 b wherewi is the wholesale price offered for production modei andb is a return price offered for items left over at the end of the season we find that such a contract can coordinate the manufacturer and distributor to act in the best interest of the channel the pricing conditions needed to ensure an efficient solution vary depending on the degree of demand forecast improvement between periods and the manufacturer s access to forecast information we also examine whether these conditions ensure a pareto optimal solution with respect to two traditional production settings

social mobility and redistributive politics just like economists voters have conflicting views about redistributive taxation because they estimate its incentive costs differently we model rational agents as trying to learn from their dynastic income mobility experience the relative importance of effort and predetermined factors in the generation of income inequality and therefore the magnitude of these incentive costs in the long run left wing dynasties believing less in individual effort and voting for more redistribution coexist with right wing dynasties this allows us to explain why individual mobility experience and not only current income matters for political attiitudes and how persistent differences in perceptions about social mobility can generate persistent differences in redistribution across countries

strategic investments trading and pricing under forecast updating this paper considers two independent firms that invest in resources such as capacity or inventory based on imperfect market forecasts as time progresses and new information becomes available the firms update their forecasts and have the option to trade their resources the trade contract is determined as the bargaining equilibrium or alternatively as the price equilibrium assuming a fairly general form of the profit functions we characterize the nash equilibrium investment levels which are first best under the price equilibrium trade contract but not under the bargaining equilibrium trade contract to gain additional insights we then focus on firms that face stochastic demand functions with constant price elasticity and have contingent pricing power assuming a general forecast evolution process we characterize the impact of the option to trade and the firms cooperation on equilibrium investments expected prices profits and consumer surplus finally to study the main driving forces of trading we employ a well established and empirically tested forecast updating model in which the forecast evolution process follows a two dimensional geometric brownian motion under this model we prove that the equilibrium investments expected prices profits and consumer surplus are nondecreasing in the quality and timing of forecast revisions in market variability and in foreign exchange volatility but are nonincreasing in market correlation

inclusion of flexibility benefits in discounted cash flow analyses for investment evaluation a simulation optimization model abstract it has been argued that conventional discounted cash flow dcf techniques which are commonly used for investment justification are inadequate and may even be inappropriate for the justification of advanced manufacturing systems whose strategic value comes from such attributes as flexibility the problem lies in the proper estimation of the value of flexibility in financial or cash flow terms so that the dcf techniques which are otherwise conceptually sound become relevant this involves an assessment of the value of the flexibility of the manufacturing system in dealing with the uncertainties in its operating environment we propose a simulation optimization methodology for this assessment in cash flow terms and use it in a dcf framework we use simulation to generate the environmental parameters in each period of an appropriate evaluation horizon we develop a mathematical programming model to determine the distribution of the possible net revenues of the system in each period by capturing the combined effect of the different types of flexibilities that the manufacturing system may possess we illustrate the application of our methodology using numerical examples and discuss how it can be used to assess the value of flexibility in cash flow terms we show that our approach facilitates the justification of capital investment in advanced manufacturing systems which tend to get undervalued under the traditional dcf approaches it would also help managers address such important questions as how much incremental investment should we be willing to make now for the additional flexibility features and does the expected present value of the future benefits of added flexibility justify the incremental capital investment now in essence our paper addresses the question as to appropriate techniques or approaches for justifying proposed strategic investment decisions

perceptions of equity and the distribution of income this article develops a model in which quit rates and thus the income distribution depend on employee perceptions of the accuracy of employer assessments of individual productivity because these latter assessments affect wages when employees believe that these assessments are accurate income inequality tends to be high the model can account for the negative correlation across some countries of inequality and the extent to which inequality is deemed to be excessive it also fits the contrast in u s and french experiences concerning the tenure of highly educated workers with high wages relative to the tenure of lower paid workers

modeling process switching decisions under product life cycle uncertainty abstract we address the process switching decision of a firm that adopts a mixed process strategy with respect to a new product in the context of product life cycle uncertainty a mixed process strategy uses a flexible process in the early stages of the product s life cycle and later switches to a dedicated process to gain cost economies we present a model that captures uncertainty through alternative life cycle demand functions to guide the process switching decision we develop a dynamic decision rule that can be used with any uncertainty resolution scheme and demonstrate its application and robustness using an illustrative numerical example

endogenous indoctrination occupational choices the evolution of beliefs and the political economy of reforms i analyse a model where workers self select in the educational occupation in a way which is correlated with their beliefs about the working of the market economy teachers have a disproportionate effect on the transmission of beliefs therefore they generate a bias which makes it harder for the population to learn the true parameters of the economy if these are favourable to the market economy two parameters determine this bias social entropy defines how predictable one s occupation is as a function of one s beliefs heritability is the weight of the family s beliefs in the determination of the priors of a new generation both heritability and social entropy reduce the bias and make it easier to learn that the market economy is good under the assumption that it is

managing flexible capacity in a make to order environment flexible capacity has been shown to be very effective to hedge against forecast errors at the investment stage in a make to order environment this flexibility can also be used to hedge against variability in customer orders in the short term for that purpose production levels must be adjusted each period to match current demands to give priority to the higher margin product or to satisfy the closest customer however this will result in swings in production inducing larger order variability at upstream suppliers and significantly higher component inventory levels at the manufacturer through a stylized two plant two product capacitated manufacturing setting we show that the performance of the system depends heavily on the allocation mechanism used to assign products to the available capacity although managers would be inclined to give priority to higher margin products or to satisfy customers from their closest production site these practices lead to greater swings in production result in higher operational costs and may reduce profits

inventory management under price based and stockout based substitution abstract we examine a stochastic inventory and pricing problem for a firm that sells two vertically differentiated products the demands for the two products are determined by total random market size and the customers net utility from buying the two products which is determined by the products quality attributes the individual quality valuation unknown to the firm and the selling prices in case the preferred product is out of stock customers may be willing to buy a substitute instead if their net utility is non negative therefore we analyze an inventory and pricing model considering price based and stockout based substitution we show that the demand function is not continuous in price by decomposing the profit function into different price regimes we are able to derive closed form expressions for the stockout based substitution rates upward and downward substitution and the optimal inventory levels under exogenous pricing under endogenous pricing we find that the profit function is not necessarily unimodal however we show that a unique solution exists for the integrated price and inventory problem under price based substitution only numerical results reveal that not considering stockout based substitution i leads to lower profit margins for high quality products and ii may cause severe supply demand mismatches throughout the entire assortment finally we show the performance of two approximated pricing policies

budget allocation for permanent and contingent capacity under stochastic demand we develop a model of budget allocation for permanent and contingent workforce under stochastic demand the level of permanent capacity is determined at the beginning of the horizon and is kept constant throughout whereas the number of temporary workers to be hired must be decided in each period compared to existing budgeting models this paper explicitly considers a budget constraint under the assumption of a restricted budget the objective is to minimize capacity shortages when over expenditures are allowed both budget deviations and shortage costs are to be minimized the capacity shortage cost function is assumed to be either linear or quadratic with the amount of shortage which corresponds to different market structures or different types of services we thus examine four variants of the problem that we model and solve either approximately or to optimality when possible a comprehensive experimental design is designed to analyze the behavior of our models when several levels of demand variability and parameter values are considered the parameters consist of the initial budget level the unit cost of temporary workers and the budget deviation penalty reward rates varying these parameters produce several trade offs between permanent and temporary workforce levels and between capacity shortages and budget deviations numerical results also show that the quadratic cost function leads to smooth and moderate capacity shortages over the time periods whereas all shortages are either avoided or accepted when the cost function is linear

optimizing the use of contingent labor when demand is uncertain abstract we develop a new model for flexible workforce management in environments with uncertainty in the demand for labor in particular we model a workforce comprised of regular workers who have fixed schedules and may work overtime and contingent workers whose working hours are flexible as specified by a contract over a finite planning horizon our model can represent a variety of contracts including temporary workers on call workers with guaranteed minimum pay and comp time arrangements we formulate the model as an optimization problem that determines the regular and contingent worker pool sizes that minimize expected labor and backlog costs embedded within this problem is a dynamic programming problem of making optimal operational staffing decisions with respect to the utilization of contingent and overtime resources numerical examples demonstrate the effect that the timing of information has on the benefits of flexibility we also derive structural results that may be exploited to reduce the computational effort required to use the model

long lasting effects of socialist education abstract political regimes influence the content of education and criteria used to select and evaluate students we study the impact of a socialist education on the likelihood of obtaining a college degree and on several labor market outcomes by exploiting the reorganization of the school system in east germany after reunification our identification strategy uses cutoff birth dates for school enrollment that lead to variation in the length of exposure to the socialist education system within the same birth cohort an additional year of socialist education decreases the probability of obtaining a college degree and affects longer term labor market outcomes for men

disagreement and learning about reforms when it comes to economic reforms in developing countries many economists agree on broad objectives broad objectives however can be pursued in different ways and policy experimentation is often indispensable for learning which alternative works locally we propose a theoretical model to study this societal learning process the model explores the role of disagreeing beliefs about what works it suggests that such disagreement can stall the societal learning process and cause economic stagnation although everyone knows that growth promoting reforms do exist our analysis is motivated by the observation of a negative relationship between disagreement and economic growth among poorer countries

strategic facility location capacity acquisition and technology choice decisions under demand uncertainty robust vs non robust optimization approaches abstract this paper presents a robust optimization ro modeling approach to develop insights into strategic capacity planning and resource acquisition decisions including the facility location problem and the technology choice problem the main purpose of the proposed model and numerical experiments is to examine the effects of economies of scale economies of scope and the combined effects of scale and scope under uncertain demand realizations using robust optimization the type of capacities or technology alternatives that a firm can acquire can be classified on two basic dimensions the first dimension relates to the effects of scale via distinction between labor intensive technologies and capital intensive technologies the second dimension relates to the effects of scope via distinction between product dedicated and flexible technologies moreover each product dedicated and flexible technology can have different levels of labor or capital intensity leading to the joint effects of economies of scale and economies of scope extensive computational results document how the optimal technology choice patterns depend on the cost structures and levels of model robustness specified to accommodate uncertain demand realizations the results obtained by the two stage robust optimization approach are compared to the results obtained by a non robust approach

skiba points in free end time problems abstract since the end of the seventies skiba points have been studied in infinite time optimal control problems with multiple steady states at such a skiba point the decision maker is indifferent between choosing trajectories that approach different steady states this paper extends this theory towards free end time optimal control problems where the decision maker collects a salvage value at the endogenous horizon date in particular besides operating forever the decision maker can choose to stop operations immediately or to operate during a finite time interval after which the decision maker stops and collects a salvage value this paper illustrates the new theory with a firm level capital accumulation problem in which the manager has the option to sell the firm be acquired at any time this situation may be relevant for certain high tech start ups that create intellectual property which may be of value to an acquiring firm and which is hard for an outside firm to tap in other ways e g via licensing

integrating resource and production decisions in a simple multi stage assembly system we consider a simple multi stage assembly system with stationary stochastic demand for a single final product that is made to stock the assembly tasks are performed by human resources this workforce consists of two parts regular workforce with a long term contract and temporary workforce that are contracted based on the actual demand contracting resources early is always cheaper than contracting later when we separate resource and production decisions we can first determine order up to levels and production decisions in a standard way and afterwards find the best mix of regular and temporary workforce next to this decoupled approach we present an integrated approach where these decisions influence each other in a set of examples we show that the integrated approach can be very beneficial

social mobility and the demand for redistribution the poum hypothesis this paper examines the often stated idea that the poor do not support high levels of redistribution because of the hope that they or their offspring may make it up the income ladder this prospect of upward mobility poum hypothesis is shown to be fully compatible with rational expectations and fundamentally linked to concavity in the mobility process a steady state majority could even be simultaneously poorer than average in terms of current income and richer than average in terms of expected future incomes a e rst empirical assessment suggests on the other hand that in recent u s data the poum effect is probably dominated by the demand for social insurance in the future everyone will be world famous for e fteen minutes andy warhol 1968

the macroeconomics of labor and credit market imperfections labour market frictions are not the only possible source of high unemployment credit market imperfections driven by microeconomic frictions and influenced by macroeconomic factors could also be to blame to develop this idea in a simple and tractable macroeconomic model we treat credit and labour market imperfections in a symmetrical way accordingly we introduce specificity in credit relationships and assume that credit to potential entrepreneurs is rationed due to endogenous search frictions in the spirit of diamond 1990 these imperfections mirror job search frictions in the labour market we study the determination of equilibrium unemployment in the presence of credit market frictions both with exogenous and endogenous wages we explore a number of possible extensions endogenous destruction monetary policy and the short run effects of financial liberalization

long term capacity decisions in uncertain markets for advanced manufacturing systems incorporating scope economies abstract by examining the literature in the field of manufacturing flexibility many researchers have located several form of flexibility by distinguishing them into strategic and operational flexibility forms furthermore many measures and design methods have been proposed for flexible manufacturing systems surely scope economies are one of the most important strategic form of flexibility in manufacturing systems and their strategic impact has been acknowledged by the very beginning of the flexible manufacturing era however despite several researches are available to address scope economies measurement and design methodologies very few researches investigate their economic convenience in front of dedicated manufacturing systems depending on the competitive market conditions this paper proposes a theoretical model whose main aim is the general understanding of the convenience conditions of scope economies based manufacturing systems the results of the theoretical model are very interesting because they locate market conditions that make scope economies manufacturing systems less profitable than dedicated manufacturing ones moreover the proposed model sets some general criteria to guide the entrepreneur in making right investment decision regarding this kind of manufacturing investments such results can explain the reason of many failures of flexible manufacturing systems and it suggests the use of this kind of approach to investigate other flexibility forms of manufacturing systems the ultimate goal of this research is the construction of a decision support system for supporting the entrepreneur in making decision on advanced manufacturing systems investment decisions

competition and investment in flexible technologies this paper examines the implications of market structure on investment in flexible manufacturing systems fms we analyze a two stage game in which firms choose between a flexible and a less flexible technology in the first stage then choose production quantities in the second stage in equilibrium a large proportion of fms firms is associated with more concentrated markets our model predicts that a larger market and or a more differentiated product results in a higher proportion of fms firms being sustained these predictions are empirically supported using cross section industry level data from both the us and japan

coordinating the resource investment decision for a two market price setting firm abstract we study the capacity investment decision of a two product firm that is a price setter for both products the products are of varying complexities such that the resource that can be used to produce the higher level product can also be used to produce the lower level one but not vice versa although the firm needs to make its capacity investment decision under demand uncertainty it can utilize this limited downward resource flexibility in addition to pricing to more effectively match its supply with demand as an example consider a firm that owns a main plant satisfying both end product and intermediate product demand and a subsidiary satisfying the intermediate product demand only we formulate this decision problem as a two stage stochastic programming problem with recourse and analyze the impact of coordinated decision making when the resource flexibility is taken into account in the investment decision and demand correlation on the firm s optimal investment strategy our results offer managerial principles on the firm s optimal resource investment strategy

strategic technology choice and capacity investment under demand uncertainty this paper studies the impact of competition on a firm s choice of technology product flexible or product dedicated and capacity investment decisions specifically we model two firms competing with each other in two markets characterized by price dependent and uncertain demand the firms make three decisions in the following sequence choice of technology technology game capacity investment capacity game and production quantities production game the technology and capacity games occur while the demand curve is still uncertain and the production game is postponed until after the demand curve is revealed we develop best response functions for each firm in the technology game and compare how a monopolist and a duopolist respond to a given flexibility premium we show that the firms may respond to competition by adopting a technology which is the same as or different from what the competitor adopts we conclude that contrary to popular belief flexibility is not always the best response to competition flexible and dedicated technologies may coexist in equilibrium we demonstrate that as the difference between the two market sizes increases a duopolist is willing to pay less for flexible technology whereas the decision of a monopolist is not affected further we find that a firm that invests in flexibility benefits from a low correlation between demands for two products but the extent of this benefit differs depending on the competitor s technology choice our results indicate that higher demand substitution may or may not promote the adoption of flexibility under competition whereas it always facilitates the adoption of flexibility without competition finally we show that contrary to intuition as the competitor s cost of capacity increases the premium a flexible firm is willing to pay for flexibility decreases

dedicated vs product flexible production technology strategic capacity investment choice this paper studies the optimal investment strategies of an incumbent and a potential entrant that can both choose between a product flexible and dedicated technology in a two product market characterized by uncertain demand the product flexible production technology has certain advantages especially when the economic environment is uncertain on the other hand the dedicated production technology allows a firm to commit to production quantities this gives strategic advantages which can outweigh the value of flexibility it turns out that both firms prefer for some scenarios the dedicated production technology however we find that in a game with sequential technology choices both firms investing dedicated will not be an equilibrium especially when the economic environment is more uncertain the incumbent overinvests in product flexible capacity to force the entrant to choose the dedicated technology then the incumbent is the only firm with the product flexible production technology which results in a high payoff

dynamic capacity management with general upgrading this paper studies a capacity management problem with upgrading a firm needs to procure multiple classes of capacities and then allocate the capacities to satisfy multiple classes of customers that arrive over time a general upgrading rule is considered i e unmet demand can be satisfied using multistep upgrade no replenishment is allowed and the firm has to make the allocation decisions without observing future demand we first characterize the structure of the optimal allocation policy which consists of parallel allocation and then sequential rationing specifically the firm first uses capacity to satisfy the same class demand as much as possible then considers possible upgrading decisions in a sequential manner we also propose a heuristic based on certainty equivalence control to solve the problem numerical analysis shows that the heuristic is fast and delivers close to optimal profit for the firm finally we conduct extensive numerical studies to derive insights into the problem it is foun

debt deflation financial market stress and regime change evidence from europe using mrvar the economic meltdown since 2008 9 has created disinflation and even deflation in some countries in the euro area in a period with large debt overhang creating the condition for a continuing financial market stress in the euro area as disinflation and deflation push up the real interest rate while growth and income declines the leveraging problem becomes more severe and the economy risks shifting into a regime with high insolvency risk high financial stress rising credit spreads possibly accompanied by strong adverse macroeconomic feedback loops investigating the consequences of those magnifying feedback loops given the debt deflation we demonstrate the possibility of unstable dynamics and downward spirals in the presence of regime dependent macro feedback loops using a theoretical model with decentralized matching mechanisms on both labor and financial markets to explore the amplifying linkages between deflation output labor and financial markets we employ a new solution procedure called nmpc to solve our models variants for out of steady state dynamics we empirically explore deflationary trends in europe and employ a global var gvar model for a large euro area macro data set to estimate the impact of deflation on output moreover we use a four variable multi regime var mrvar model with regime dependent irs to study deflationary as well as well as the financial risk drivers in a mrvar setting new measures for financial risk drivers are employed and multi regime irs for output inflation rates interest rates and financial stress are explored we also study regime changes in central macro relationships such as regime change in the credit output link the phillips curve and in okun s law

optimal capacity for substitutable products under operational postponement abstract we consider a monopolist producing two substitutable products with one flexible shared capacity the demand of each product is a linear function of the prices of both products and is subject to an additive shock we study the impact of two key drivers namely the degree of substitution between the products and the level of operational postponement on the optimal capacity and the resulting expected profit we show that the relationship between the optimal capacity and the degree of product substitution is not impacted by the different postponement strategies the firm can utilize or by the different settings forced clearance versus holdback considered in the previous literature on the other hand how capacity is affected by postponement critically depends on how closely substitutable the products are in particular we show that the well known result that operational postponement and capacity are strategic complements in a single product setting van mieghem and dada 1999 no longer holds in our setting because the two substitutable products are now linked through consumer driven substitution which the firm can influence through pricing in particular capacity and operational postponement in the form of quantity postponement can be either strategic substitutes or strategic complements and this depends on both the firm s cost structure and the degree of substitution between the products we also study the impact of forced clearance on the firm s expected profit and find that clearance deteriorates the firm s earnings more when the products it offers are highly differentiated

optimal investment in product flexible manufacturing capacity this paper presents a model and an analysis of the cost flexibility tradeoffs involved in investing in product flexible manufacturing capacity flexible capacity provides a firm with the ability to respond to a wide variety of future demand outcomes but at the expense of the increased cost of acquiring flexible manufacturing capacity as compared with dedicated or nonflexible capacity we formulate the product flexible manufacturing capacity investment decision as a two stage stochastic program in the first stage the firm must make its investment decision in manufacturing capacity before the resolution of uncertainty in product demand in the second stage after demand for products are known the firm implements its production decisions constrained by the first stage investments the main contributions of this paper are threefold first we develop a model of the firm s flexible manufacturing investment decision that conceptually captures some of the key characteristics of this complex decision probl

business cycles and labor market search the quantitative implications of labor market search for economic fluctuations are evaluated in the context of a real business cycle model incorporating labor market search into the model is found to improve its empirical performance along several dimensions in particular hours now fluctuate substantially more than wages and the contemporaneous correlation between hours and productivity falls in addition the model replicates the observation that output growth displays positive autocorrelation at short horizons overall the empirical results suggest that the labor market search environment embodies a quantitatively important propagation mechanism copyright 1996 by american economic association

preferences for redistribution in the land of opportunities this paper explores how individual preferences for redistribution depend on future income prospects in addition to estimating the impact of individuals socioeconomic background and of their subjective perceptions of future mobility we employ panel data to construct dobjectivet measures of expected gains and losses from redistribution for different categories of individuals we find that such measures have considerable explanatory power and perform better than dgeneral mobilityt indexes we also find that preferences for redistribution respond to individual beliefs on what determines one s position in the social ladder ceteris paribus people who believe that the american society offers equal opportunities are more averse to redistribution d 2004 published by elsevier b v

economics of efficiency measurement by the dea approach three aspects of efficiency measurement by data envelopment analysis are discussed here analytically these aspects comprise output specific input allocations by each firm flexibility in the production process and the role of learning by doing in efficiency improvement

a brownian approximation of a production inventory system with a manufacturer that subcontracts this paper considers a production inventory problem where a manufacturer fulfills stochastic stationary demand for a single product from a finished goods inventory the inventory can be replenished by two production resources in house production and a subcontractor which both have finite capacity we construct a brownian approximation of the optimal control problem assuming that the manufacturer uses a dual base stock policy to control replenishment from the two sources and that her objective is to minimize average cost a closed form expression is obtained for one optimal base stock policy and an analytical expression is derived from which the other optimal base stock can be computed numerically we show conditions under which the objective is convex in capacity and the unique globally optimal capacity can be computed numerically we thus provide a tractable approximation to the two source problem which is generally intractable we demonstrate the accuracy of this approximation for an m m 1 model we also draw managerial insight from the brownian optimal base stock results into how the optimal base stock policies control the inventory distribution and under what conditions the contingent source is used to build inventory or to resolve backorders

flexible production resources and capacity utilization rates a robust optimization perspective abstract this paper presents a novel application of robust optimization ro in the context of optimal choices of product dedicated and flexible capacities in a spatial setting specifically we examine the impact of acquiring flexible production technologies on a firm s overall capacity utilization rates under demand uncertainty uncorrelated negatively and positively correlated demands are considered we implement an efficient ro algorithm which can solve large samples of robust min max problems in a realistic amount of time this paper examines the impact of three critical factors that lead to different capacity utilization and resource flexibility outcomes the degree of solution robustness selected by the decision maker to accommodate uncertain demand realizations the flexible capacity costs relative to dedicated capacity costs and the level of correlation between product demands one of our results show that according to robust solutions the total capacity may not be fully utilized because of the distinction between largest in unit terms and costliest demand realizations the second result shows that increasing the proportion of flexible capacity can increase capacity utilization however our results report less than full utilization even when using flexible capacity only we show that the optimal amount of flexible capacity and its impact on overall capacity utilization rate substantially depends on demand correlation

investments in flexible production capacity abstract we examine the technology and capacity choice problem of a multi output firm facing stochastic demands in a continuous time framework the firm can install output specific capital or at greater cost flexible capital that can be used to produce different outputs investment is irreversible the firm must choose a technology and decide how much capital to install knowing it can add more later as demand evolves we formulate the capacity choice problem as a singular stochastic control problem show that the value of the firm equals the value of its installed capital plus the value of its options to add capacity in the future and derive an optimal investment rule that maximizes the firm s market value we also address the analogous problem for a multi input firm that faces stochastically evolving factor costs and can install input specific or flexible capital

excess capacity in a fixed cost economy abstract this paper proposes a new mechanism that can explain persistent economic slack the theory shows that when producers face negligible marginal costs and desired spending is below the economy s capacity the economy features slack in equilibrium even when prices are flexible and there are no other frictions a heterogeneous household version of the model demonstrates how an economy can enter a capacity trap in response to a temporary negative demand shock when demand by some consumers falls temporarily other consumers permanent income and hence their desired consumption also falls since output is determined by demand the permanent fall in desired consumption causes a permanent state of excess capacity

flexible service capacity optimal investment and the impact of demand correlation we consider a firm that provides multiple services using both specialized and flexible capacity the problem is formulated as a two stage single period stochastic program the firm invests in capacity before the actual demand is known and optimally assigns capacity to customers when demand is realized sample applications include a car rental company s use of mid sized cars to satisfy unexpectedly high demand for compact cars and an airline s use of business class seats to satisfy economy class demand we obtain an analytical solution for a particular case when services may be upgraded by one class the simple form of the solution allows us to compare the optimal capacities explicitly with a solution that does not anticipate flexibility given that demand follows a multivariate normal distribution we analytically characterize the effects of increasing demand correlation on the optimal solution for the case with two customer classes the effects of demand correlation are intuitive increasing correlation induces a shift from flexible to dedicated capacity when there are three or more classes there are also adjustments to the resources not directly affected by the correlation change as correlation rises these changes follow an alternating pattern for example if the optimal capacity of one resource rises then the optimal capacity of the adjacent resource falls these results make precise conjectures based on numerical experiments that have existed in the literature for some time

the value of flexibility in make to order systems the effect of demand correlation we consider a manufacturer of mass customized modular products who orders components under demand uncertainty and sets prices produces to order and trades excess components in a secondary market after this uncertainty is resolved the sequence of events reflects in a parsimonious fashion the considerable reduction in demand uncertainty between the procurement stage and the selling season typical of industries with long supply lead times and short product life cycles we prove that in contrast to conventional wisdom the value of production flexibility and expected profit increase with demand correlation if and only if commonality between the corresponding products does not exceed a threshold we also prove that the value of flexibility and expected profit may each increase or decrease with demand variability depending on demand correlations and component commonalities across the entire product line finally we prove that when demand shocks are independent the optimal product prices are positively correlated if and only if the degree of commonality between the corresponding products exceeds a threshold

component commonality with service level requirements this paper extends recent results of baker et al baker k r m j magazine h l w nuttle 1986 the effect of commonality on safety stocks in a simple inventory model management sci 32 982 988 in understanding the impact of component commonality on stocking levels under service level constraints a model is formulated for an arbitrary number of products with general joint demand distribution the results obtained are not all intuitive while utilizing commonality is beneficial nothing general can be said about the resulting change in the components stock levels when the cost structure is of a particular simple form though some interesting general patterns do emerge we also discuss the case of using a service level measure where rationing of common components might be required and characterize the implied rationing rule

time to build option value and investment decisions abstract investment decisions and outlays are often made sequentially for example the rate at which construction proceeds is usually flexible and can be adjusted with the arrival of new information traditional discounted cash flow methods which treat the pattern of investment as fixed ignore this flexibility and understate the value of the project this paper uses contingent claims analysis to derive optimal decision rules and to value such investments we determine the effects of time to build opportunity cost and uncertainty on the investment decision for reasonable parameter values we show how a simple npv rule can lead to gross errors

machine and labor flexibility in manufacturing networks abstract many industrial companies today operate under strict employment legislation and work agreements since flexible capacity has been widely recognized as an important hedge against uncertain demand there exist strong efforts to introduce more flexible workforce models in this paper we investigate the benefits of such labor flexibility and its interplay with machine flexibility from a network capacity investment perspective we consider a firm that has to invest simultaneously in labor and machine capacity under uncertain demand and a given network configuration while anticipating the deployment of labor flexibility after demand has been realized instruments of labor flexibility range from temporary employment to personnel transfers between plants the underlying decision problem is formulated as a two stage stochastic program with recourse based on numerical studies and the analysis of a stylized model we demonstrate the impact of labor flexibility on the optimal levels of machine and labor capacity we compare the benefits obtained by personnel transfers with those of temporary workers and find that temporary employment always decreases the number of permanent workers while personnel transfers may even allow for a larger workforce our results further indicate that personnel transfers are more effective in larger manufacturing networks although these benefits are decreasing when most plants in the network are capable of producing more than one product machine flexibility finally we present evidence for the efficiency of a combined usage of personnel transfers and temporary workers

operational flexibility and financial hedging complements or substitutes we consider a firm that invests in capacity under demand uncertainty and thus faces two related but distinct types of risk mismatch between capacity and demand and profit variability whereas mismatch risk can be mitigated with greater operational flexibility profit variability can be reduced through financial hedging we show that the relationship between these two risk mitigating strategies depends on the type of flexibility product flexibility and financial hedging tend to be complements substitutes i e product flexibility tends to increase decrease the value of financial hedging and vice versa financial hedging tends to increase decrease the value of product flexibility when product demands are positively negatively correlated in contrast to product flexibility postponement flexibility is a substitute to financial hedging as intuitively expected although our analytical results assume perfect flexibility and perfect hedging and rely on a linear approximation of the value of hedging we validate their robustness in an extensive numerical study

pricing and operational recourse in coproduction systems coproduction systems in which multiple products are produced simultaneously in a single production run are prevalent in many industries such systems typically produce a random quantity of vertically differentiated products this product hierarchy enables the firm to fill demand for a lower quality product by converting a higher quality product in addition to the challenges presented by random yields and multiple products coproduction systems often serve multiple customer classes that differ in their product valuations furthermore the sizes of these classes are uncertain employing a utility maximizing customer model we investigate the production pricing downconversion and allocation decisions in a two class stochastic demand stochastic yield coproduction system for the single class case we establish that downconversion will not occur if prices are set optimally in contrast we show that downconversion can be optimal in the two class case even if prices are set optimally we consider the benefit of postponing certain operational decisions e g the pricing or allocation rule decisions until after uncertainties are resolved we use the term recourse to denote actions taken after uncertainties have been resolved we find that recourse pricing benefits the firm much more than either downconversion or recourse allocation do implying that recourse demand management is more valuable than recourse supply management special cases of our model include the single class and two class random yield newsvendor models

process flexibility in supply chains process flexibility whereby a production facility can produce multiple products is a critical design consideration in multiproduct supply chains facing uncertain demand the challenge is to determine a cost effective flexibility configuration that is able to meet the demand with high likelihood in this paper we present a framework for analyzing the benefits from flexibility in multistage supply chains we find two phenomena stage spanning bottlenecks and floating bottlenecks neither of which are present in single stage supply chains which reduce the effectiveness of a flexibility configuration we develop a flexibility measureg and show that increasing this measure results in greater protection from these supply chain inefficiencies we also identify flexibility guidelines that perform very well for multistage supply chains these guidelines employ and adapt the single stage chaining strategy of jordan and graves 1995 to multistage supply chains

technology investment under flexible capacity strategy with demand uncertainty abstract this paper investigates technology investment under flexible capacity strategy with demand uncertainty technology investment enables a firm to reduce its total production cost while flexible capacity strategy aims to reduce a firm s production waste by postponing production until demand is known adopting a general technology investment cost we examine how technology investment cost structure affects a firm s technology investment decisions we derive the conditions under which the firm will benefit from technology investment we show that the firm can increase its expected profit through technology investment only when the unit technology investment cost that varies inversely with the basic technology level is below a threshold however even though the technology investment cost is zero the benefit from the increase in technology level is limited furthermore we analytically determine the optimal technology levels and establish their relationships under different technology investment cost structures our findings will help firms evaluate various technology investment options and choose the most proper one