supply chain relationships and contracts the impact of repeated interaction on capacity investment and procurement consider a firm developing an innovative product due to market pressures production must begin soon after the product development effort is complete which requires that an upstream supplier invests in capacity while the design of the product and production process are in flux because the product is ill defined at this point in time the firms are unable to write court enforceable contracts that specify the terms of trade or the supplier s capacity investment however the firms can adopt an informal agreement relational contract regarding the terms of trade and capacity investment the potential for future business provides incentive for the firms to adhere to the relational contract we show that the optimal relational contract may be complex requiring the buyer to order more than her demand to indirectly monitor the supplier s capacity investment we propose a simpler relational contract and show that it performs very well for a broad range of parameters finally we identify characteristics of the business environment that make relational contracting particularly valuable

optimal pricing and return policies for perishable commodities this paper considers the pricing decision faced by a producer of a commodity with a short shelf or demand life a hierarchical model is developed and the results of the single period inventory model are used to examine possible pricing and return policies the paper shows that several such policies currently in effect are suboptimal these include those where the manufacturer offers retailers full credit for all unsold goods or where no returns of unsold goods are permitted the paper also demonstrates that a policy whereby a manufacturer offers retailers full credit for a partial return of goods may achieve channel coordination but that the optimal return allowance will be a function of retailer demand therefore such a policy cannot be optimal in a multi retailer environment it is proven however that a pricing and return policy in which a manufacturer offers retailers a partial credit for all unsold goods can achieve channel coordination in a multi retailer environment this article was originally published in marketing science volume 4 issue 2 pages 166 176 in 1985

planning under incomplete information and the ratchet effect abstract central planning of production is usually performed under asymmetric information the firm in general has more information about its productive possibilities than the central planner from now on for short cp this justifies the use of incentives schemes in which the cp does not directly fix activity levels casual observation of such existing schemes suggests that the time dimensions is crucial for their working typically the cp revises the incentive scheme over time to take into account the information provided by the firm s performance managers of centrally planned economies as well as economists have long recognized that this revision induces firms to underproduce in order to avoid demanding schemes in the future this is the ratchet effect it is purpose of the present paper to study the ratchet effect under the non commitment assumption which we believe to be more realistic the inadequacy of conceptual tools made if difficult in the past to consider such an assumption now basic research on dynamic games with incomplete information recently resulted in new ideas which look particularly relevant for a theoretical analysis of the problem

designing supply contracts contract type and information asymmetry this paper studies the value to a supplier of obtaining better information about a buyer s cost structure and of being able to offer more general contracts we use the bilateral monopoly setting to analyze six scenarios three increasingly general contracts wholesale pricing schemes two part linear schemes and twopart nonlinear schemes each under full and incomplete information about the buyer s cost structure we allow both sides to refuse to trade by explicitly including reservation profit levels for both for the supplier this is implemented through a cutoff policy we derive the supplier s optimal contracts and profits for all six scenarios and examine the value of information and of more general contracts our key findings are as follows first the value of information is higher under two part contracts second the value of offering two part contracts is higher under full information and third the proportion of buyers the supplier will choose to exclude can be substantial

tastes and technology in a two country model of the business cycle explaining international trade on international financial markets allows people to insure country specific risk and smooth consumption intertemporally equilibrium models of business cycles with trade on global financial markets typically yield international consumption correlations near one and excessive volatility of investment the authors incorporate nontraded goods in the model and find that the implications for aggregate consumption investment and the trade balance are consistent with business cycle properties of industrialized countries however the model driven by technology shocks alone yields counterfactual implications for comovements between consumption and prices at the sectoral level taste shocks produce price quantity relationships more consistent with the data copyright 1995 by american economic association

the outlook for us oil dependence abstract oil dependence is defined as a dynamic problem of short and long run market power the potential monopoly power of an oil cartel depends on its market share and the elasticities of oil supply and demand while the economic vulnerability of oil consuming states depends most directly on the quantity of oil imported and the oil cost share of gross domestic product gdp of these factors only the market share of the organization of petroleum exporting countries opec cartel and the rate of growth of world oil demand are clearly different than they were 25 years ago opec still holds the majority of world oil and in the future will regain market share a hypothetical 2 year supply reduction in 2005 2006 similar in size to those of 1973 1974 or 1979 1980 illustrates the potential benefits to opec and harm to the us economy of a future oil price shock opec s revenues are estimated to increase by roughly 0 7 trillion while the us economy loses about 0 5 trillion strategic petroleum reserves seem ineffective against a determined multi year supply curtailment increasing the market s price responsiveness by improving the technologies of oil supply and oil demand can greatly reduce the costs of oil dependence each element of this interpretation of the oil dependence problem is well supported by previous studies this paper s contribution is to unite these elements into a coherent explanation and to point out the enormously important implications for energy policy

fuel taxes an important instrument for climate policy abstract this article shows that fuel taxes serve a very important role for the environment and that we risk a backlash of increased emissions if they are abolished fuel taxes have restrained growth in fuel demand and associated carbon emissions although fuel demand is large and growing our analysis shows that it would have been much higher in the absence of domestic fuel taxes people often assert that fuel demand is inelastic but there is strong research evidence showing the opposite the price elasticity is in fact quite high but only in the long run in the short run it may be quite inelastic which has important implications for policy makers had europe not followed a policy of high fuel taxation but had low us taxes then fuel demand would have been twice as large hypothetical transport demand in the whole oecd area is calculated for various tax scenarios and the results show that fuel taxes are the single most powerful climate policy instrument implemented to date yet this fact is not usually given due attention in the debate

interdependent international relations and the expansion of ethanol production and consumption the brazilian perspective abstract the global production and consumption of ethanol are expected to increase the growing interdependence of markets and nations producers and consumers of biofuels has led actors to seek and devise mechanisms intended to develop the sector this paper aims to analyze the interdependent international relations between brazil and other ethanol biofuel producer and consumer countries to do so the paper explores the theory of complex interdependence and the game theory a quali quantitative study was conducted involving the application of two questionnaires to experts on biofuels and documentary analysis aided by qda miner software the results show that brazil shares highly interdependent relations with the united states an intermediate degree of interdependence with europe and a low degree of interdependence with china the dimensions of those interdependent relations can be ranked according to importance in the following order first the political then the economic technical and finally the social environmental dimensions a number of actions can be envisaged that could lead ethanol to achieve an increasingly strategic position in the diversification of the energy matrix in different countries technological efforts to improve production efficiency the creation of globally integrated policies designed to provide security and develop the production and consumption infrastructure the reduction of international tariffs on the product and the transformation of ethanol into a global commodity with a large number of countries buying and selling the product this paper faced the challenge of integrating approaches and concepts from two complex theoretical areas complex interdependence theory and game theory the research methodology and the insights gained from the ethanol case contribute to the literature on the applicability of these two theoretical approaches

risk sharing and real exchange rates the role of non tradable sector and trend shocks abstract in this paper we show that the tradable and non tradable total factor productivity tfp processes of the us and europe have unit roots and can be modeled by a vector error correction model vecm then we develop a standard two country and two good tradable and non tradable dsge model our model implies that using cointegrated tfp processes and including non tradables help solve the real exchange rate rer volatility and risk sharing puzzles cointegrated tfp shocks or trend shocks generate significant income effects and amplify the mechanisms that produce high rer volatility moreover trend shocks can break the tight link between relative consumption and rer for low and high values of trade elasticity parameters the non tradable sector in the model improves the results for the risk sharing significantly

the price of anarchy in supply chains quantifying the efficiency of price only contracts in this paper we quantify the efficiency of decentralized supply chains that use price only contracts with a price only contract a buyer and a seller agree only on a constant transaction price without specifying the amount that will be transferred it is well known that these contracts do not provide incentives to the parties to coordinate their inventory capacity decisions we measure efficiency with the price of anarchy poa defined as the largest ratio of profits between the integrated supply chain that is fully coordinated and the decentralized supply chain we characterize the efficiency of various supply chain configurations push or pull inventory positioning two or more stages serial or assembly systems single or multiple competing suppliers and single or multiple competing retailers

the geopolitics of cross border electricity grids the israeli arab case abstract countries often attempt to establish regional electricity grids however whereas research on natural resources frequently seeks to understand policy outcome through a geopolitical prism when it comes to electricity studies the prism is always economic or technical hence this study is a first attempt to identify the geopolitical dimension of cross border electricity grids the study argues that success in establishing electricity grids requires identifying how the geopolitical dimension interplays with the physical dimension to examine the role of these geopolitical bottlenecks the study examines negotiation protocols spanning over 15 years on establishing ten grid connections between israel and its arab neighbors it finds that electricity geopolitics has been used both as a platform for deeper international cooperation and as a stick against neighboring states when policies are driven by a peace dividend proposals for grid connection appear to evolve and overcome the dependency and the security economy bottlenecks when relations deteriorate proposals for grid connections appear to undergo reconsideration and to be held hostage by higher politics if when and how electricity grids materialize is a function of the nature of the electricity network as a twofold package and of the ability of the planning process to accommodate geopolitical uncertainty

towards sustainability of energy systems a primer on how to apply the concept of energy services to identify necessary trends and policies virtually all goods and services that characterize modern societies welfare depend on the provision of commercial energy the core objective of this paper is to identify necessary changes in trends for achieving a transition towards more sustainable energy systems and development paths the major conclusions of this analysis are i a rigorous rethinking process has to take place to identify which level of energy services per capita lead to enhancing human welfare and quality of life ii a significant increase in energy conversion efficiency has to be triggered to finally provide energy services with far less input of energy than today iii a continuous increase in the share of renewable energy sources and other low emission options has to be brought about iv however as history has shown this process of technological learning has to be accompanied by proper energy price and regulatory policies otherwise it is very likely that energy conservation gains due to technical efficiency improvements will be outweighed again by increases in energy service demand and straightforward energy consumption and co 2 emissions

do trade costs in goods market lead to home bias in equities abstract two of the main puzzles in international economics are the consumption and the portfolio home biases we solve for international equity portfolios in a two country two good stochastic equilibrium model with trade costs in goods markets we show that introducing trade costs as suggested by obstfeld and rogoff obstfeld m rogoff k 2000a the six major puzzles in international macroeconomics is there a common cause nber macroeconomics annual 15 is not sufficient to explain these two puzzles simultaneously on the contrary we find that trade costs create a foreign bias in portfolios for reasonable parameter values this result is robust to the addition of non tradable goods for standard calibrations of the preferences

home bias and high turnover dynamic portfolio choice with incomplete markets why do investors trade a lot in foreign assets and hold so little of them in their portfolios this paper shows that both observations can arise naturally in the presence of nondiversifiable nontraded consumption risk when each country specializes in production preferences exhibit consumption home bias and asset markets are incomplete using a general equilibrium two country two sector tradable and nontradable model of the world economy with production i show that low diversification occurs because variations in relative prices i increase the riskiness of foreign assets and ii facilitate risk sharing across countries large and volatile capital flows are necessary to take advantage of international risk premia differentials that occur in response to productivity changes in the nontradable sector i characterize the optimal portfolio holdings the evolution of the investment opportunity set the risk premium and the dynamics of capital flows using a new methodology for solving dynamic general equilibrium models with incomplete markets and portfolio choice

dynamic bargaining in a supply chain with asymmetric demand information we analyze a dynamic bargaining game in which a seller and a buyer negotiate over quantity and payment to trade for a product both firms are impatient and they make alternating offers until an agreement is reached the buyer is privately informed about his type which can be high or low the high type s demand is stochastically larger than the low type s in the dynamic negotiation process the seller can screen whereas the buyer can signal information through their offers and the buyer has an endogenous and type dependent reservation profit with rational assumptions on the seller s belief structure we characterize the perfect bayesian equilibrium of the bargaining game interestingly we find that both quantity distortion and information rent may be avoided depending on the firms relative patience and the seller may reach an agreement with either the high type or the low type first or with both simultaneously furthermore we explore our model to characterize the effect of demand forecasting accuracy on firm profitability we find that improved demand forecast benefits the buyer but hurts the seller when the buyer s forecasting accuracy is low however once the buyer s forecasting accuracy exceeds a threshold both firms will benefit from further improvement of the forecast this observation makes an interesting contrast to previous findings based on the one shot principal agent model in which improvement of forecasting accuracy mostly leads to a win lose outcome for the two firms and the buyer has an incentive to improve his forecasting accuracy only when it is extremely low this paper was accepted by yossi aviv operations management

international portfolios capital accumulation and foreign assets dynamics despite the liberalization of capital ows among oecd countries equity home bias remains sizable we depart from the two familiar explanations of equity home bias transaction costs that impede international diversi cation and terms of trade responses to supply shocks that provide risk sharing so that there is little incentive to hold diversi ed portfolios we show that the interaction of the following ingredients generates a realistic equity home bias capital accumulation shocks to the e ciency of physical investment as well as international trade in stocks and bonds in our model domestic stocks are used to hedge uctuations in local wage income terms of trade risk is hedged using bonds denominated in local goods and in foreign goods in contrast to related models the low level of international diversi cation does not depend on strongly countercyclical terms of trade the model also reproduces the cyclical dynamics of foreign asset positions and of international capital ows

international real business cycles we ask whether a two country real business cycle model can account simultaneously for domestic and international aspects of business cycles with this question in mind we document a number of discrepancies between theory and data the most striking discrepancy concerns the correlations of consumption and output across countries in the data outputs are generally more highly correlated across countries than consumptions in the model we see the opposite

does britain or the united states have the right gasoline tax this paper develops an analytical framework to assess the second best optimal level of gasoline taxation taking into account unpriced pollution congestion and accident externalities as well as interactions with the broader fiscal system we provide calculations of the optimal taxes for the us and the uk under a variety of parameter scenarios under our central parameter values the second best optimal gasoline tax is 1 01 gal for the us and 1 34 gal for the uk current tax rates are much lower than this in the us and higher in the uk the calculations are moderately sensitive to alternative parameter assumptions the congestion externality is the largest component in both nations revenue raising needs also play a significant role as do accident externalities and local air pollution potential welfare gains from reducing the current uk tax rate are estimated at nearly one fourth the production cost of all gasoline used in the uk even larger gains could be achieved by switching to a tax on vehicle miles with equal revenue yield for the us the welfare gains from optimizing the gasoline tax are smaller but those from switching to an optimal tax on vehicle miles are very large

energy security and sustainability in northeast asia abstract energy security has typically to those involved in making energy policy meant mostly securing access to oil and other fossil fuels with increasingly global diverse energy markets however and increasingly transnational problems resulting from energy transformation and use old energy security rationales are less salient and other issues including climate change and other environmental economic and international considerations are becoming increasingly important as a consequence a more comprehensive operating definition of energy security is needed along with a workable framework for analysis of which future energy paths or scenarios are likely to yield greater energy security in a broader more comprehensive sense work done as a part of the nautilus institute s pacific asia regional energy security pares project developed a broader definition of energy security and described an analytical framework designed to help to compare the energy security characteristics both positive and negative of different quantitative energy paths as developed using software tools such as the leap long range energy alternatives planning system

information distortion in a supply chain the bullwhip effect this article originally appeared in management science april 1997 volume 43 number 4 pp 546 558 published by the institute of management sciences consider a series of companies in a supply chain each of whom orders from its immediate upstream member in this setting inbound orders from a downstream member serve as a valuable informational input to upstream production and inventory decisions this paper claims that the information transferred in the form of orders tends to be distorted and can misguide upstream members in their inventory and production decisions in particular the variance of orders may be larger than that of sales and distortion tends to increase as one moves upstream a phenomenon termed bullwhip effect this paper analyzes four sources of the bullwhip effect demand signal processing rationing game order batching and price variations actions that can be taken to mitigate the detrimental impact of this distortion are also discussed

indicators of energy security in industrialised countries energy security has become a popular catch phrase both in the scientific arena as well as in the political discussion yet in general the applied concepts of energy security are rather vague this paper sheds some light on concepts and indicators of energy security first we conceptually discuss the issue of energy supply security and explain why it is not to handle by one science alone and what economics may contribute in order to structure the topic after providing a brief survey of existing attempts to define or measure energy security we suggest an additional dimension along which indicators of energy security may be classified ex post and ex ante indicators finally we illustrate our concept on the basis of several simplified indicators while ex post indicators are mostly based on price developments ex ante indicators are to a greater extent aimed at illustrating potential problems our illustration suggests that it is worthwhile to take into account the market structure along with the political stability of exporting countries

adverse selection and renegotiation in procurement as was shown by dewatripont optimal long term contracts are generally not sequentially optimal the parties ex post renegotiate them to their mutual advantage this paper fully characterizes the equilibrium of a simple two period procurement situation and studies the extent to which renegotiation reduces ex ante welfare i a central result is that like in the non commitment case the second period allocation is optimal for the principal conditionally on his posterior beliefs about the agent ii the first period allocation exhibits an increasing amount of pooling when the discount factor grows iii with a continuum of types it is never optimal to induce full separation the paper also analyzes whether renegotiated long term contracts yield outcomes resembling those under either unnegotiated long term contracts or a sequence of short term contracts and it links the analysis with the multiple unit durable good monopoly problem

the dynamics of incentive contracts the paper studies a simple two period principal agent model in which the principal updates the incentive scheme after observing the agent s first period performance the agent has superior information about his ability the principal offers a first period incentive scheme and observes some measure of the agent s first period performance cost or profit which depends on the agent s ability and unobservable first period effort the relationship is entirely run by short term contracts in the second period the principal updates the incentive scheme and the agent is free to accept the new incentive scheme or to quit the strategies are required to be perfect and updating of the principal s beliefs about the agent s ability follows bayes rule the central theme of the paper is that the ratchet effect leads to much pooling in the first period first for any first period incentive scheme there exists no separating equilibrium second when the uncertainty about the agent s ability is small the optimal scheme must involve a large amount of pooling the paper also gives necessary and sufficient conditions for the existence of partition equilibria and looks at the effect of cost uncertainty

technical note optimal long term supply contracts with asymmetric demand information we consider a manufacturer selling to a retailer with private demand information arising dynamically over an infinite time horizon under a backlogging model we show that the manufacturer s optimal dynamic long term contract takes a simple form in the first period based on her private demand forecast the retailer selects a wholesale price and pays an associated upfront fee and from then on the two parties stick to a simple wholesale price contract with the retailer s chosen price under a lost sales model we show that the structure of the optimal long term contract combines a menu of wholesale pricing contracts with an option that if exercised by the retailer reduces future wholesale prices in exchange for an immediate payment to the manufacturer the online appendix is available at https doi org 10 1287 opre 2017 1626

in the name of energy security the struggle over the exportation of israeli natural gas the aim of this study is to place the notion of energy security under critical scrutiny by unpacking how different actors manipulate the term through the mobilization of existential language as a prism for creating securitization discourse through an examination of an israeli inter ministerial committee charged with developing national policy regarding newly discovered natural gas reserves off the coast of israel the study finds that the concept of energy security is open for manipulation and various interpretations while some actors stress environmental acceptability and independency as pillars of energy security others prioritized supply reliability and geopolitical benefits associated with gas exportation each definition of energy security was also found to be anchored in different ideologies goals policies and legitimizing factors the coupling of energy with securitization rhetoric was ultimately determined as working against cooperative efforts as committee conflicts intensified and suggested institutional measures became disproportional

financial globalization and monetary policy abstract recent data show substantial increases in the size of gross external asset and liability positions the implications of these developments for optimal conduct of monetary policy are analyzed in a standard open economy model which is augmented to allow for endogenous portfolio choice the model shows that monetary policy takes on new importance due to its impact on nominal asset returns nevertheless the case for price stability as an optimal monetary rule remains in fact it is reinforced even without nominal price rigidities price stability is optimal because it enhances the risk sharing properties of nominal bonds

borders and nominal exchange rates in risk sharing models of risk sharing predict that relative consumption growth rates are positively related to changes in real exchange rates we investigate this hypothesis using a new multicountry and multiregional data set within countries we find evidence for risk sharing episodes of high relative regional consumption growth are associated with regional real exchange rate depreciation across countries however the association is reversed relative consumption and real exchange rates are negatively correlated we define this reversal as a border effect we find the border effect and show that it accounts for over half of the deviations from full risk sharing since cross border real exchange rates involve different currencies it is natural to ask how much of the border effect is accounted for by movements in exchange rates our measures indicate that a large part of the border effect comes from nominal exchange rate fluctuations we develop a simple open economy model that is consistent with the importance of nominal exchange rate variability in accounting for deviations from cross country risk sharing

sustaining long term supply chain partnerships using price only contracts abstract in this paper we study how an informal long term relationship between a manufacturer and a retailer performs in turbulent market environments characterized by uncertain demand we show that the long term partnership based on repeated interaction is sustainable under price only contracts when the supply chain partners are sufficiently patient that is the channel can be coordinated over a long time horizon when the factor whereby the members discount the future value of this trusting relationship is sufficiently high second above the minimum discount factor a range of wholesale prices exists that can sustain the long term partnership and there are different possible profit divisions between the two players third when the market is turbulent i e either the expected demand or the demand variance changes from period to period according to a probabilistic law it is typically less possible to sustain the long term partnership in a booming market or in a market with low demand variability finally obtaining more information about future market fluctuation may not help the supply chain to sustain the long term partnership due to partners strategic considerations with the availability of the market signal total supply chain profits increase but the retailer may even be worse off

a supplier s optimal quantity discount policy under asymmetric information in the supply chain literature an increasing body of work studies how suppliers can use incentive schemes such as quantity discounts to influence buyers ordering behaviour thus reducing the supplier s and the total supply chain s costs various functional forms for such incentive schemes have been proposed but a critical assumption always made is that the supplier has full information about the buyer s cost structure we derive the optimal quantity discount policy under asymmetric information and compare it to the situation where the supplier has full information

the international transmission of economic fluctuations abstract this paper suggests that for a wide class of international real business cycle models including models with imperfect competition the traditional channels of international transmission of business cycles through world interest rate and terms of trade variations cannot explain the cyclical response of the canadian economy to innovations in u s output empirically testable quantitative models of the effects on canadian economic activity of shocks to the u s economy are developed and their empirical relevance is tested by comparing impulse responses estimated from vector autoregressions to the quantitative predictions of the theoretical models

consumption and real exchange rates in dynamic economies with non traded goods abstract we examine the possibility that non traded goods may account for several striking features of international macroeconomic data large persistent deviations from purchasing power parity small correlations of aggregate consumption fluctuations across countries and substantial international real interest rate differentials a dynamic exchange economy is used to show that non traded goods in principle can account for each of these phenomena in the theory there is a close relation between fluctuations in consumption ratios and those in bilateral real exchange rates but we find little evidence for this relation in time series data for eight oecd countries

supply chain performance under market valuation an operational approach to restore efficiency based on a supply chain framework we study the stocking decision of a downstream buyer who receives private demand information and has the incentive to influence her capital market valuation we first characterize a market equilibrium under a general single buyback contract we show that the buyer s stocking decision can be distorted in equilibrium such a downstream stocking distortion hurts the buyer firm s own performance and it also influences the performances of the supplier and the supply chain we further reveal scenarios where full supply chain efficiency cannot be reached under any single buyback contract then focusing on contract design we characterize conditions under which a menu of buyback contracts can prevent downstream stocking distortion and restore full efficiency in the supply chain our study demonstrates that in a supply chain context a firm s incentive to undertake real economic activities to influence capital market valuation can potentially be resolved through operational means this paper was accepted by yossi aviv operations management

contract renegotiation and coasian dynamics consider a long term relationship between a seller and a buyer whose valuation for a per period service or a durable good is private as trade progresses the valuation will be partially revealed and it may be impossible for the parties to commit ex ante not to take advantage of this we analyse this situation first by supposing that the parties can sign a sequence of short term contracts and secondly by supposing that they can sign a long term contract but cannot commit not to renegotiate it later we find a close relationship in the second case between the optimal long term contract and the non commitment outcome in the standard coasian durable good model our results also have implications for hidden information principal agent models

abandoning the concept of renewable energy abstract renewable energy is a widely used term that describes certain types of energy production in politics business and academia renewable energy is often framed as the key solution to the global climate challenge we however argue that the concept of renewable energy is problematic and should be abandoned in favor of more unambiguous conceptualization building on the theoretical literature on framing and based on document analysis case examples and statistical data we discuss how renewable energy is framed and has come to be a central energy policy concept and analyze how its use has affected the way energy policy is debated and conducted we demonstrate the key problems the concept of renewable energy has in terms of sustainability incoherence policy impacts bait and switch tactics and generally misleading nature after analyzing these issues we discuss alternative conceptualizations and present our model of categorizing energy production according to carbon content and combustion the paper does not intend to criticize or promote any specific form of energy production but instead discusses the role of institutional conceptualization in energy policy

optimal dynamic procurement policies for a storable commodity with levy prices and convex holding costs abstract in this paper we study a continuous time stochastic inventory model for a commodity traded in the spot market and whose supply purchase is affected by price and demand uncertainty a firm aims at meeting a random demand of the commodity at a random time by maximizing total expected profits we model the firm s optimal procurement problem as a singular stochastic control problem in which controls are nondecreasing processes and represent the cumulative investment made by the firm in the spot market a so called stochastic monotone follower problem we assume a general exponential levy process for the commodity s spot price rather than the commonly used geometric brownian motion and general convex holding costs we obtain necessary and sufficient first order conditions for optimality and we provide the optimal procurement policy in terms of a base inventory process that is a minimal time dependent desirable inventory level that the firm s manager must reach at any time in particular in the case of linear holding costs and exponentially distributed demand we are also able to obtain the explicit analytic form of the optimal policy and a probabilistic representation of the optimal revenue the paper is completed by some computer drawings of the optimal inventory when spot prices are given by a geometric brownian motion and by an exponential jump diffusion process in the first case we also make a numerical comparison between the value function and the revenue associated to the classical static newsvendor strategy

international capital flows abstract the surge in international asset trade since the early 1990s has lead to renewed interest in models with international portfolio choice we develop the implications of portfolio choice for both gross and net international capital flows in the context of a simple two country dynamic stochastic general equilibrium dsge model we focus on the time variation in portfolio allocation following shocks and resulting capital flows endogenous time variation in expected returns and risk which are the key determinants of portfolio choice affect capital flows in often subtle ways the model is consistent with a broad range of empirical evidence an additional contribution of the paper is to overcome the technical difficulty of solving dsge models with portfolio choice by developing a broadly applicable solution method

an exploration into pigou s theory of cycles abstract this paper explores a theory of business cycles in which recessions and booms arise due to difficulties encountered by agents in properly forecasting the economy s future needs in terms of capital the idea has a long history in the macroeconomic literature as reflected by the work of pigou industrial fluctuation macmillan london 1926 the contribution of this paper is twofold first we illustrate the type of general equilibrium structure that can give rise to such phenomena second we examine the extent to which such a model can explain the observed pattern of u s recessions frequency depth without relying on technological regress we argue that such a model offer a framework for understanding elements of both the recent u s recession and of the asia downturns of the late 1990s

a unified world oil market regions in physical economic geographic and political space although there is a general consensus that the market is unified here we quantify the factors that create regions by analyzing the price relation between 33 crude oils adf statistics indicate that 447 of the 528 crude oil pairings cointegrate 81 do not the presence absence of cointegration is analyzed using a logit model the likelihood that the prices for two crude oils cointegrate depends on their physical characteristics density and sulfur content economic factors country risk for the nation of origin their geographic location distance between supply ports and political factors opec membership over the sample period the technology to refine heavy crude oils penetrates the market and this reduces the price difference between heavy and light crude oils the effect of country risk implies that crude oils from high risk nations are not perfect substitutes for crude oils of similar quality from low risk nations finally crude oils from widely separated suppliers are more likely to cointegrate than crude oils from near by nations which suggests consumers diversify supply across transportation chokepoints for this sample these sources of regionalization add 0 20 per barrel to the 2 86 average price difference between crude oils in the same market together these factors have important implications for the efficacy of policy aimed at reducing dependence on unreliable suppliers and the spill over effects of holding inventories

vertical contracts in a supply chain and the bullwhip effect this paper shows that decentralized supply chains in which upstream firms use linear wholesale prices may experience lower upstream production and downstream sales volatility than vertically inte

strategic inventories in vertical contracts classical reasons for carrying inventory include fixed nonlinear production or procurement costs lead times nonstationary or uncertain supply demand and capacity constraints the last decade has seen active research in supply chain coordination focusing on the role of incentive contracts to achieve first best levels of inventory an extensive literature in industrial organization that studies incentives for vertical controls largely ignores the effect of inventories does the ability to carry inventory influence the problem of vertical control conversely can inventories arise purely due to incentive effects this paper explicitly considers both incentives and inventories and their interplay in a dynamic model of an upstream firm supplier and a downstream firm buyer who can carry inventories in our model none of the classical reasons for carrying inventory exists however as we prove the buyer s optimal strategy in equilibrium is to carry inventories and the supplier is unable to prevent

security independence and sustainability imprecise language and the manipulation of energy policy in the united states abstract this article examines the impact of imprecise terminology on the energy policymaking process in us focusing on the manipulation of discourse by different political economic interests seeking to sway popular opinion using the 2012 us presidential elections as a backdrop the analysis highlights the cooption of the concepts security independence and sustainability in energy debates by different and often opposing interest groups the article s first section traces the malleability of energy terminology to the vagueness of the term energy itself and notes how qualifying words like security independence and sustainability have been selectively exploited to introduce further ambiguity to an already fungible concept the second section notes that while energy is a critical and complex factor of macroeconomic production its main public visibility comes via a few partially representative numbers like gasoline prices this mismatch of broad social importance and piecemeal public understanding enables organized interests to leverage vague terminology in support of particular policy ideas the third section examines three policymaking tools 1 taxation 2 regulation and 3 technology promotion and compares these administrative instruments ultimately the article concludes that loosely defined terminology inhibits energy policy discussion and stifles meaningful public debate over and action on energy issues

procuring fast delivery sole sourcing with information asymmetry this paper studies a queuing model in which a buyer sources a good or service from a single supplier chosen from a pool of suppliers the buyer seeks to minimize the sum of her procurement and operating costs the latter of which depends on the suppliers lead time the selected supplier can regulate his lead time but faster lead times are costly although the buyer selects the supplier to source from possibly via an auction and dictates the contractual terms the buyers bargaining power is limited by asymmetric information the buyer only has an estimate of the suppliers costs while the suppliers know their costs precisely we identify a procurement mechanism that minimizes the buyers total cost procurement plus operating this mechanism is not simple it is a numerically derived nonlinear menu of contracts therefore we study several simpler mechanisms e g one that charges a late fee and one that specifies a fixed lead time requirement no menus no nonlinear functions we find that simple mechanisms are nearly optimal generally within 1 of optimal because asymmetric information conveys significant protection to the supplier i e the supplier is able to retain most of the benefit of having a lower cost renegotiation is another concern with the optimal mechanism because it does not minimize the supply chains cost the firms can be both better off if they throw away the contract and start over interestingly we find that the potential gain from renegotiation is relatively small with either the optimal or our simple mechanisms we conclude that our simple mechanisms are quite attractive along all relevant dimensions buyers performance supply chain performance simplicity and robustness to renegotiation

the external wealth of nations measures of foreign assets and liabilities for industrial and developing countries abstract although capital flows are closely monitored surprisingly little is known about the accumulated stocks of foreign assets and liabilities held by various countries especially in the developing world this paper constructs estimates of foreign assets and liabilities and their equity and debt subcomponents for a sample of 67 industrial and developing countries it characterizes the stylized facts of international balance sheets and asks whether there are trends in net foreign asset positions and shifts in debt equity ratios over time finally it explores the sensitivity of estimated stock positions to the treatment of valuation effects not captured in balance of payments data

consumption real exchange rates and the structure of international asset markets abstract international real business cycle irbc models that assume complete asset markets yield strong restrictions for consumption and bilateral real exchange rate series empirical tests with data for the us japan france uk italy canada and sweden suggest that neither the trend behavior nor high frequency movements of consumption and real exchange rates are well explained by irbc models with complete markets it appears however that high frequency fluctuations of consumption and real exchange rates are consistent with unrestricted international trade in risk free bonds

portfolio allocation and international risk sharing we show that recent explanations of the consumption real exchange rate anomaly that rely on goods and financial market frictions are not robust to introducing just one additional international asset when portfolios are selected optimally international trade in two nominal bonds implies a consumption real exchange rate correlation that is too high compared with the data even when there are many shocks monetary policy specification plays a potentially important role for the degree of risk sharing provided by nominal bonds both in the benchmark model with only tradable and non tradable sector supply shocks and also in the model that allows for news

stalking information bayesian inventory management with unobserved lost sales retailers are frequently uncertain about the underlying demand distribution of a new product when taking the empirical bayesian approach of scarf 1959 they simultaneously stock the product over time and learn about the distribution assuming that unmet demand is lost and unobserved this learning must be based on observing sales rather than demand which differs from sales in the event of a stockout using the framework and results of braden and freimer 1991 the cumulative learning about the underlying demand distribution is captured by two parameters a scale parameter that reflects the predicted size of the underlying market and a shape parameter that indicates both the size of the market and the precision with which the underlying distribution is known an important simplification result of scarf 1960 and azoury 1985 which allows the scale parameter to be removed from the optimization is shown to extend to this setting we present examples that reveal two interesting phenomena 1 a retailer may hope that compared to stocking out realized demand will be strictly less than the stock level even though stocking out would signal a stochastically larger demand distribution and 2 it can be optimal to drop a product after a period of successful sales we also present specific conditions under which the following results hold 1 investment in excess stocks to enhance learning will occur in every dynamic problem and 2 a product is never dropped after a period of poor sales the model is extended to multiple independent markets whose distributions depend proportionately on a single unknown parameter we argue that smaller markets should be given better service as an effective means of acquiring information

long term energy services security what is it and how can it be measured and valued abstract the paper reviews some recent approaches towards measuring the extent of long term energy security and security externality valuation it starts out to discuss the contextual connotations of notions of energy security in medium to long term time frames and reviews some indicators that have been proposed to quantify it special attention is paid to two of these approaches which the authors helped to develop i e diversity based indices and the supply demand index the paper takes issue with conventional welfare economic approaches that neglect i the scope on the demand side for raising security and ii negative feedback mechanisms of socio political impacts of international rent transfers in fossil fuels exporting countries the concept of energy services security is proposed with a demand side focus this enables application of an integrated approach to gauge the resilience of a society to meet the needs of its population for energy services over longer timescales ahead from various interrelated perspectives propositions are made on the attribution of security externalities to the use of fossil fuels policies and suggestions for further improvements of measures for energy services security

indicators for energy security the concept of energy security is widely used yet there is no consensus on its precise interpretation in this research we have provided an overview of available indicators for long term security of supply sos we distinguished four dimensions of energy security that relate to the availability accessibility affordability and acceptability of energy and classified indicators for energy security according to this taxonomy there is no one ideal indicator as the notion of energy security is highly context dependent rather applying multiple indicators leads to a broader understanding incorporating these indicators in model based scenario analysis showed accelerated depletion of currently known fossil resources due to increasing global demand coupled with increasing spatial discrepancy between consumption and production international trade in energy carriers is projected to have increased by 142 in 2050 compared to 2008 oil production is projected to become increasingly concentrated in a few countries up to 2030 after which production from other regions diversifies the market under stringent climate policies this diversification may not occur due to reduced demand for oil possible benefits of climate policy include increased fuel diversity and slower depletion of fossil resources

dynamic supplier contracts under asymmetric inventory information in this paper we examine a supply chain in which a single supplier sells to a downstream retailer we consider a multiperiod model with the following sequence of events in period t the supplier offers a contract to the retailer and the retailer makes her purchasing decision in anticipation of the random demand the demand then unravels and the retailer carries over any excess inventory to the next period unmet demand is lost in period t 1 the supplier designs a new contract based on his belief of the retailer s inventory and the game is played dynamically we assume that short term contracts are used i e the contracting is dynamically conducted at the beginning of each period we also assume that the retailer s inventory before ordering is not observed by the supplier this setting describes scenarios in which the downstream retailer does not share inventory sales information with the supplier for instance it captures the phenomenon of retailers distorting past sales information to secure better contracting terms from their suppliers we cast our problem as a dynamic adverse selection problem and show that given relatively high production and holding costs the optimal contract can take the form of a batch order contract which minimizes the retailer s information advantage we then analyze the performance of this type of contract with respect to some useful benchmarks and quantify the value of prudent contract design and the value of inventory information to the supply chain markovian adverse selection models in which the state and action in a period affect the state in the subsequent period are recognized as theoretically challenging and are relatively less understood we take a nontrivial step towards a better understanding of such models under short term contracting

news and business cycles in open economies we study the effects of news about future total factor productivity tfp in a small open economy we show that an open economy version of the neoclassical model produces a recession in response to good news about future tfp we propose an open economy model that generates comovement in response to tfp news the key elements of our model are a weak short run wealth effect on the labor supply and adjustment costs to labor and investment we show that our model also generates comovement in response to news about future investment specific technical change and to sudden stops

country portfolios in open economy macro models this paper develops a simple approximation method for computing equilibrium portfolios in dynamic general equilibrium open economy macro models the method is widely applicable simple to implement and gives analytical solutions for equilibrium portfolio positions in any combination or types of asset it can be used in models with any number of assets whether markets are complete or incomplete and can be applied to stochastic dynamic general equilibrium models of any dimension so long as the model is amenable to a solution using standard approximation methods we first illustrate the approach using a simple two asset endowment economy model and then show how the results extend to the case of any number of assets and general economic structure

dynamic business share allocation in a supply chain with competing suppliers this paper studies a repeated game between a manufacturer and two competing suppliers with imperfect monitoring we present a principal agent model for managing long term supplier relationships using a unique form of measurement and incentive scheme we measure a supplier s overall performance with a rating equivalent to its continuation utility the expected total discounted utility of its future payoffs and incentivize supplier effort with larger allocations of future business we obtain the vector of the two suppliers ratings as the state of a markov decision process and we solve an infinite horizon contracting problem in which the manufacturer allocates business volume between the two suppliers and updates their ratings dynamically based on their current ratings and the current performance outcome our contributions are both theoretical and managerial we propose a repeated principal agent model with a novel incentive scheme to tackle a common but challenging incentive problem in a multiperiod s

optimal dynamic information provision abstract we study a dynamic model of information provision a state of nature evolves according to a markov chain an advisor with commitment power decides how much information to provide to an uninformed decision maker so as to influence his short term decisions we deal with a stylized class of situations in which the decision maker has a risky action and a safe action and the payoff to the advisor only depends on the action chosen by the decision maker the greedy disclosure policy is the policy which at each stage minimizes the amount of information being disclosed in that stage under the constraint that it maximizes the current payoff of the advisor we prove that the greedy policy is optimal in many cases but not always

resource allocation under demand uncertainty and private information we study the effect of multilateral private information on the efficiency of markets where capacity constrained upstream agents supply a resource to downstream entities facing uncertain end demands we analyze two models a pooling system in which a single downstream principal pools a resource from multiple upstream agents and a distribution system in which one upstream principal allocates a resource across multiple downstream agents we show that the presence of multilateral private information does not hinder efficiency in the pooling system in contrast in the distribution system the quantities allocated to downstream agents can exceed as well as fall short of their first best levels these results shed light on the recently improved performance of u s agricultural produce market and the observed episodes of shortages oversupplies in flu vaccine and other seasonal markets this paper was accepted by manel baucells decision analysis