dynamic oligopoly with incomplete information we consider learning and signalling in a dynamic cournot oligopoly where firms have private information about their production costs and only observe the market price which is subject to unobservable demand shocks an equilibrium is markov if play depends on the history only through the firms beliefs about costs and calendar time we characterize symmetric linear markov equilibria as solutions to a boundary value problem in every such equilibrium given a long enough horizon play converges to the static complete information outcome for the realized costs but each firm only learns its competitors average cost the weights assigned to costs and beliefs under the equilibrium strategies are non monotone over time we explain this by decomposing incentives into signalling and learning and discuss implications for prices quantities and welfare

technology factor proportions and competitiveness the paper reports an attempt to explain changes in the industrial pattern of relative international competitiveness and specialization in the swedish manufacturing industry during the period 1969 84 in particular we evaluate the role of rd this was true for industries intensive in human as well as physical capital the analysis confirmed the technology gap hypothesis in that a high level of rd on the other hand no indication was found of increased international specialization on r d intensive products in swedish industry

factor endowments factor proportions and the allocative efficiency of u s interregional trade the heckscher ohlin h o theory of trade has been subjected to numerous international tests based upon the empirical evidence presented in the literature it appears that the theory s explanatory power of the actual pattern of international trade is somewhat limited this may not be surprising however when one considers a host of extraneous factors such as tariffs quotas and other policy and institutional barriers to trade which distort the pattern of trade on the other hand some of the requisites of the h o theory are more nearly satisfied in interregional trade within a nation the extent of policy distortions on the overall pattern of commodity trade should be far less in interregional trade than in international trade likewise both production technologies and demand conditions assumed to be identical between nations in the h o theory should be more nearly so among regions within a nation while the theoretical basis of regional trade is of course the same as that of international trade it is primarily for these reasons that a number of researchers have more recently turned to interregional trade for the purpose of testing the h o theory the current literature on the u s regional comparative advantage includes the contributions by moroney and walker 1966 moroney 1972 1975 estle 1967 and klaasen 1973 whereas these studies focused primarily on the pattern of regional production as revealed by value added concentration ratios for the u s south the major objectives of this paper are i to design and perform factor proportion tests based upon the actual interregional pattern of trade and ii to investigate one neglected empirical aspect of the h o theory bearing upon the substitutive role that commodity trade plays for direct factor mobility in section ii we present estimates of the regional distribution of major input supplies in the united states the input classes considered are capital equipment human capital labor and renewable and nonrenewable natural resources in particular we have found that there are fairly distinct differences among u s census regions pertaining to relative aggregate input supplies defined by physical capital labor ratio human capital labor ratio renewable natural resource labor ratio and nonrenewable resource labor ratio section iii presents the methodology and major empirical findings of the factor proportions test as adapted to interregional trade section iv extends the analysis to consider an alternative hypothesis of the h o theory based on the substitutive relationship between direct factor movements and commodity trade as embedded in the original h o theory this aspect of the theory has not been explicitly dealt with in the empirical literature and we consider its practical implication concerning the allocative efficiency of trade a summary section concludes the paper

consumer scores and price discrimination we study the implications of aggregating consumers purchase histories into scores that proxy for unobserved willingness to pay a long lived consumer interacts with a sequence of firms each firm relies on the consumer s current score a linear aggregate of noisy purchase signals to learn about her preferences and to set prices if the consumer is strategic she reduces her demand to manipulate her score which reduces the average equilibrium price firms in turn prefer scores that overweigh past signals relative to applying bayes rule with disaggregated data as this mitigates the ratchet effect and maximizes the firms ability to price discriminate consumers with high average willingness to pay benefit from data collection because the gains from low average prices dominate the losses from price discrimination finally hidden scores those only observed by the firms reduce demand sensitivity increase average prices and reduce consumer surplus sometimes below the naive consumer level

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

performance comparisons and dynamic incentives it is well known that comparative performance information cpi can enhance efficiency in static principal agent relationships by improving the trade off between insurance and incentives in the design of explicit contracts in dynamic settings however there may be implicit as well as explicit incentives for example managerial career concerns and the ratchet effect in regulation we show that the dynamic effects of cpi on implicit incentives can either reinforce or oppose the familiar static insurance effect and in either case can be more important for efficiency the overall welfare effects of cpi are thus ambiguous and can be characterized in terms of the underlying information structure

why has u s inflation become harder to forecast we examine whether the u s rate of price inflation has become harder to forecast and to the extent that it has what changes in the inflation process have made it so the main finding is that the univariate inflation process is well described by an unobserved component trend cycle model with stochastic volatility or equivalently an integrated moving average process with time varying parameters this model explains a variety of recent univariate inflation forecasting puzzles and begins to explain some multivariate inflation forecasting puzzles as well

the direction of developing country trade empirical evidence of differences between south south and south north trade abstract declining market opportunities in northern markets led to views that greater south south trading might provide an alternative growth stimulus this paper analyses the characteristics of south south trade in manufactures and recent changes in the level of such trade to help clarify the potential of greater self reliance within the south south south trade is found to be more intensive in the use of both physical and human capital hence less rational from the static comparative advantage viewpoint than south north trade there is indirect but strong evidence that exporting countries with greatest orientation towards the south are those with greater distortions less rapid movements up the ladder of comparative advantage and weaker export performance finally it is observed that the recent boom in south south trade is largely explained by simple market size effects very rapid growth of rich oil exporters and the faster gnp growth of developing compared to developed countries the paper concludes that while south south trade of about the present magnitude one of greater developing country exports is certainly rational there is little evidence to support views that greater south south trade should be especially promoted arguments of dynamic comparative advantage may favor south south trade but so far these have been more speculative and not yet well researched empirically

determinants of the structure of u s foreign trade 1958 1976 abstract the heckscher ohlin model with three direct factor inputs is borne out for u s net exports of manufactures in annual cross section regressions for 1958 1976 the coefficient on unskilled labor became significantly more negative over the period and there is evidence that the negative sign on physical capital may reflect the inclusion of natural resource industries further analysis based upon 1960 and 1970 census years suggests the importance as well of skill and technological variables calculations of the total factor requirements of u s trade uphold the leontief paradox for 1958 but not for 1972

the leontief paradox continued or resolved cited in giancarlo gandolfo s textbook international economics i the pure theory of international trade springer verlag 1995 abstract currently unavailable this abstract was borrowed from another version of this item

comparative advantage geographic advantage and the volume of trade a functional relationship between the degree of a country s comparative advantage and the volume of its net exports of any good to its trading partner is established using a model with per unit distance transportation costs between countries coasts and their interiors the greater a country s comparative advantage the deeper its exports penetrate geographically into its trading partner the internal spatial structure of a country consists of cities on a river it is shown that population sizes wage rates and residential rental rates are greatest in the port city and decline monotonically as one moves inland copyright 1991 by royal economic society

on the incentive effects of job rotation abstract a new employee may work hard to build his reputation this effect is greatest when he starts the longer he is employed at his job the more the firm will already have learned about his ability the incentives for an employee to influence the firm s perceptions of his ability decrease over time if rotating the employee to a different job leads to new uncertainty about his ability this generates a fresh impulse for effort however job rotation also reduces the employee s time horizon thus reducing future rents from reputation this trade off leads to a unique optimum we derive a simple rule of thumb for an optimal rotation time our main results still hold for cases of complete but imperfect information transmission the incentive effects of job rotation also prevail in a setting in which skills are job specific we study several extensions rotations across multiple employees absence of commitment to a rotation time different bargaining positions discounting over time and learning by doing effects

immiserizing investment from abroad the singer prebisch thesis reconsidered the present paper lends new analytical support to the controversial singer prebisch thesis according to this well known thesis less developed countries ldcs suffer a welfare loss from secular decline in their international terms of trade for primary product exports the standard theoretical criticism of the thesis makes two basic arguments both relating to the impact of economic expansion 2 first there is no well established presumption that the terms of trade for primary products will indeed deteriorate in a growing world economy second if domestic economic expansion does happen to worsen the terms of trade for ldcs economic welfare of these countries still need not deteriorate except under bhagwati s 1958 well known conditions for immiserizing growth thus the traditional critique sees the singer prebisch thesis as an unconvincing allegation about the relationship between growth and welfare via the terms of trade the following discussion suggests an alternative more favorable interpretation of the thesis this reinterpretation focuses upon the process of foreign investment4 rather than economic growth as the essential reason for adverse changes in the terms of trade and level of welfare for ldcs exporting primary products such a focus appears to be fully consistent with the analysis of singer 19501 5 whose main

a theory of ambiguity credibility and inflation under discretion and asymmetric information this paper develops a positive theory of credibility ambiguity and inflation under discretion and asymmetric information the monetary policymaker maximizes his own politically motivated objective function that is positively related to economic stimulation through monetary surprises and negatively related to monetary growth the relative importance he assigns to each target shifts stochastically through time his current preference trade off is known to him but not to the public when choosing the state contingent path of money growth for the present and the future the policymaker compares the benefits from current stimulation with the costs associated with higher future inflation expectations current monetary growth conveys information to the public about future money growth because there is persistence in the policymaker s objectives although expectations are rational information is imperfect because monetary control procedures are imprecise as a result the public cannot correctly distinguish persistent changes of emphasis on different policy objectives from transitory monetary control errors the public becomes aware of changes gradually by observing past monetary growth credibility is defined in terms of the speed with which the public recognizes changes in the objectives of the policymaker credibility is lower the noisier monetary control and the more stable the objectives of the policymaker looser monetary control and a higher degree of time preference on the part of the policymaker induce him to produce higher and more variable monetary growth when the policymaker is free to determine the accuracy of monetary control he does not always choose the most effective control available in spite of the fact that monetary surprises always have an expected value of zero the reason is that ambiguous control procedures enable the policymaker to generate positive surprises when he cares more than on average about economic stimulation he leaves the inevitable negative surprises for periods in which he cares more about inflation prevention this result provides an explanation for the fed s preference for ambiguity recently documented by goodfriend 1986 the policymaker is more likely to pick more ambiguous control procedures the more uncertain his objectives and the higher his time preference the paper also provides a theoretical underpinning for the well documented crosscountry positive correlation between the level and the variability of inflation

dynamic pricing models for used products in remanufacturing with lost sales and uncertain quality in this paper we investigate the remanufacturing problem of pricing single class used products cores in the face of random price dependent returns and random demand specifically we propose a dynamic pricing policy for the cores and then model the problem as a continuous time markov decision process we first design a basic model that does not consider the quality uncertainty of cores and then extend our model to incorporate this factor besides proving optimal policy uniqueness and establishing monotonicity results for the optimal policy we also characterize the impact of system parameters on the optimal policies which can provide simple managerial insights finally we use computational experiments to assess the benefits of dynamic pricing compared to static pricing and identify the impacts of specific parameters on the relative merits of dynamic pricing policy

industrialisation and the factor content of latin american exports of manufactures this article shows that latin american exports of manufactures that grow consistently over time arise from both traditional as well as policy induced sources of comparative advantage case studies for argentina colombia and venezuela show that manufactures originally developed for the domestic market were exported with consistent growth rates and came to represent an important proportion of total manufacturing exports the study also shows that inter country differences in the factor content of these exports reflect both differences in original resource endowments as well as the effects of industrialisation policy

two sided learning and the ratchet principle i study a class of continuous time games of learning and imperfect monitoring a long run player and a market share a common prior about the initial value of a gaussian hidden state and learn about its subsequent values by observing a noisy public signal the long run player can nevertheless control the evolution of this signal and thus affect the market s belief the public signal has an additive structure and noise is brownian i derive conditions for an ordinary differential equation to characterize equilibrium behavior in which the long run player s actions depend on the history of the game only through the market s correct belief using these conditions i demonstrate the existence of pure strategy equilibria in markov strategies for settings in which the long run player s flow utility is nonlinear the central finding is a learning driven ratchet principle affecting incentives i illustrate the economic implications of this principle in applications to monetary policy earnings management and career concerns

managerial incentive problems a dynamic perspective the paper studies how a person s concern for a future career may influence his or her incentives to put in effort or make decisions on the job in the model the person s productive abilities are revealed over time through observations of performance there are no explicit output contingent contracts but since the wage in each period is based on expected output and expected output depends on assessed ability an implicit contract links today s performance to future wages an incentive problem arises from the person s ability and desire to influence the learning process and therefore the wage process by taking unobserved actions that affect today s performance the fundamental incongruity in preferences is between the individual s concern for human capital returns and the firm s concern for financial returns the two need be only weakly related it is shown that career motives can be beneficial as well as detrimental depending on how well the two kinds of capital returns are aligned it is well understood by now that informational externalities may place special demands on the organization of economic exchange simple price mediated markets will frequently fail in the presence of asymmetric information in that case more elaborate contractual arrangements have to be used as substitutes for the price system lately considerable effort has been devoted to the analysis of contracting under incomplete information with the objective to understand the range of economic institutions that emerge in response to the failure of the price system the analysis of moral hazard has played a prominent role in this development moral hazard problems arise when for some reason or another transacting parties cannot contract contingent on the delivery of the good for instance in buying labour services it may be that the amount of labour supplied is not directly observable precluding a simple exchange of wage for labour as a partial remedy to this problem an imperfect mutually observed signal about the supply of labour can be used as a proxy in the contract frequently output is taken as such a proxy the drawback is that output is often influenced by other factors than labour input which induce undesirable risk into the contract one is therefore faced with a tradeoff between allocating risk associated with incomplete observability and providing incentives for a proper supply of labour gaining insight into this tradeoff is important not only for understanding contracting in the small e g managerial incentive schemes but also because it is closely related to the fundamental tension between equity and efficiency in the society as a whole while our understanding of moral hazard has advanced a lot in past years it is clear that much work remains an important question that has received little attention until

a note on international trade and market structure as exports become an increasing part of industry sales the determinants of a firm s international position become increasingly important tests have supported single factors such as product life cycle lutz and green 1983 as well as multi factor models to explain the determinants of industry imports and exports stern and maskus 1981 harkness and kyle 1975 baldwin 1971 this study also presents a multi factor analysis of the determinants of u s trade patterns this study utilized the spi strategic planning institute data set which allows research at the business unit product line level results indicate that productivity and product development are the principal characteristics of high export percentage business units these findings are especially true for nonconsumer industries thus to the degree that business are concerned over the short term costs of product development direct or indirect for example insurance government aid may be required to promote u s export industries

an infinite horizon inventory model with periodic order commitment abstract this paper studies an infinite horizon inventory model of a buyer with a periodic order commitment the commitment requires the buyer to purchase at least a certain fixed amount on a periodic basis there is no extra adjustment cost should the buyer decide to order more than the basic amount we consider general discrete demand distributions we formulate a markov chain to represent the behavior of the inventory system stimulated by the solution approach to the classical gi m 1 queue we derive the steady state results and obtain the exact closed form cost function numerical examples are provided

horizontal reputation and strategic audience management we study how a decision maker uses his reputation to simultaneously influence the actions of multiple receivers with heterogenous biases the reputational payoff is single peaked around a bliss reputation at which the incentives of the average receiver are perfectly aligned we establish the existence of two equilibria characterized by repositioning toward this bliss reputation that only differ through a multiplier capturing the efficiency of reputational incentives repositioning is moderate in the more efficient equilibrium but the less efficient equilibrium features overreactions and welfare may then be lower than in the no reputation case we highlight how strategic audience management e g centralization delegation to third parties with dissenting objectives alleviates inefficient reputational incentives and how multiple organizational or institutional structures may arise in equilibrium as a result

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

the leontief paradox continued according to leamer 1980 the leontief paradox is based on a simple conceptual misunderstanding in a multifactor version of the heckscher ohlin model he argues that a capital abundant country need not have its exports more capital intensive than its importsprovided that the country s commodity trade embodies a net export of both labor and capital services as was the case for the united states in leontief s 1954 data for such a country however the model does imply that capital per worker be greater in net exports than in consumption leamer finds that this implication is indeed consistent with leontief s data this note shows however that there is another feature of the trade data which is not so easily explained the fact that the united states exported labor services is in itself paradoxical as discussed below sec ii the model which leamer uses to explain the paradox implies that a country is a net exporter of labor services if and only if its aggregate expenditure per worker is less than that in the rest of the world this implication is clearly inconsistent with the evidence reviewed below in sec iii which shows that expenditure per worker was substantially greater in the united states than the rest of the world and yet the united states exported labor services therefore a modified version of the leontief paradox continues to stand

modelling product returns in inventory control exploring the validity of general assumptions the literature on stochastic models for inventory control with product returns commonly makes the following simplifying assumptions demand and returns are each a homogeneous compound poisson process and the processes are independent of each other in this paper we explore the validity of these assumptions by analysing real data on return flows in addition we discuss practical implications of our findings and we provide insights on information management for inventory systems with return flows

measurement of the factor content of foreign trade with traded intermediate goods abstract in a recent article helpman 1984 develops readily testable bilateral restrictions in a model of international trade which preserves the spirit of heckscher ohlin trade theory important in any empirical exploration of the heckscher ohlin model is the decision of whether to employ direct or direct plus indirect calculations in determining the factor content of trade this paper extends helpman s analysis to a world of freely traded intermediate goods and shows that direct factor content calculations are the theoretically appropriate measure for use in evaluating these empirical implications of the heckscher ohlin model

new products and the factor content of international trade this paper extends the multicommodity two input version of the heckscher ohlin model to include new products on which considerable interest has been focused by the product cycle hypothesis and related analyses the extended model is then used to reexamine the implications of relative factor abundance for the capital and labor content of international commodity trade as this analysis shows the presence of new products might in principle resolve the leontief paradox under certain specific conditions

comparative advantage in manufactured goods a re appraisal japanese input coefficients are used to investigate the pattern of comparative advantage in the exportation of manufactured products in a cross country framework estimates are made for the imports of manufactured products as well as for net exports also alternative techniques of estimation are utilized and an attempt to explain the residuals in the regression equations and to indicate the predictive power of these equations is made the paper shows that patterns of comparative advantage in manufactured goods can be explained by reference to commodity characteristics and country characteristics in turn intercountry differences in the extent of trade orientation the concentration of exports and foreign direct investment explain part of the residuals of the cross country regression equations finally it has been found that the method applied permits projecting the factor intensity of trade for individual countries

an empirical investigation of the heckscher ohlin theorem further empirical tests are required to substantiate or disprove the heckscher ohlin theorem because earlier tests were based on an incorrect test statistic a multi commodity two country two factor model is constructed to test the theorem and derive an appropriate test statistic the model provides testable hypotheses for trade based on its profit and wage content rather than on its capital and labour content the results show that the 1968 trade patterns for australia ireland japan korea new zealand and the united states support the heckscherohlin theorem while those of israel kenya and the united kingdom do not une etude empirique du theoreme heckscher ohlin il faut des tests empiriques additionnels pour decider si l on doit supporter ou renvoyer le theoreme de heckscher ohlin puisque les tests anterieurs ont ete eriges sur une statistique incorrecte les auteurs developpent un modele de commerce international pour deux pays deux facteurs de production et plusieurs biens afin de pouvoir confectionner un test approprie du theoreme le modele suggere des hypotheses veifiables construites a partir des variables profits et salaires plutot qu a partir de variables comme les coefficients d intensite en capital et en travail les resultats indiquent que les patterns de commerce en 1968 pour l australie l irlande le japon la nouvelle zelande et les etats unis tendent a supporter le theoreme heckscher ohlin alors que 1 experience du kenya et du royaume uni va dans l autre sens starting with leontief s seminal paper 1953 examinations of the factoral content of international trade have cast doubt on the reliability of the heckscher ohlin theorem in these studies patterns of trade between the rest of the world and the united states japan west germany and canada contradicted the theorem while those of east germany and india supported it bharadwaj 1962 leontief 1953 1956 roskamp 1961 stolper and roskamp 1961 tatemoto and ichimura 1959 and wahl 1961 as baldwin 1971 126 stated these results effectively destroyed the comfortable confidence of economists in the simple version of the heckscher ohlin trade theory they also provoked numerous articles advancing other ways to account for the pattern of a country s trade the test statistic used for these empirical studies of the heckscher ohlin theorem was developed by leontief and further applied by later investigators although it was never set within a theoretical framework no one questioned it until williams canadian journal of economics revue canadienne d economique xvii no 1 february fevrier 1984 printed in canada imprime au canada 0008 4085 84 0000 0032 1 50 1984 canadian economics association this content downloaded from 157 55 39 104 on mon 20 jun 2016 05 49 18 utc all use subject to http about jstor org terms empirical investigation of heckscher ohlin theorem 33 published his paper in 1970 in that work williams asserted that leontief s inference is incorrect the united states is plentiful in capital and he provided a model from which he derived a correct test statistic williams 1970 from a practical point of view a major limitation of williams s model is the assumption that trade is perfectly free and that factor prices will be equalized through trade more recent papers by deardorff 1979 and brecher and choudhri 1982 have suggested in a two country context at least that the factor content condition developed by williams should hold when factor prices are unequal and there are tariffs or other impediments to trade marxsen 1983 has demonstrated that such is the case and therefore that the williams condition should hold even if factor prices are unequal and trade is tariff ridden the purpose of this paper is to provide an empirical test of the heckscher ohlin theorem in the first section a multi commodity two country two factor model is constructed and an approprite test statistic is devised based on the profit and wage content rather than the capital and labour content of trade the second section presents the empirical test results for the 1968 trade patterns of the nine countries under study in the third section these results are considered in the light of previous work and conclusions are drawn about the heckscher ohlin theorem

earnings quality evidence from the field abstract we provide insights into earnings quality from a survey of 169 cfos of public companies and in depth interviews of 12 cfos and two standard setters cfos believe that i above all high quality earnings are sustainable and repeatable specific characteristics include consistent reporting choices backing by actual cash flows and absence of one time items and long term estimates ii about 50 of earnings quality is driven by non discretionary factors such as industry and macro economic conditions iii in any given period about 20 of firms manage earnings to misrepresent economic performance and for such firms 10 of eps is typically managed iv earnings manipulation is hard to unravel from the outside but peer comparisons and lack of correspondence between earnings and cash flows provide helpful red flags in addition cfos disagree with current standard setting on a number of issues including the sheer number of promulgated rules the top down approach to rule making the neglect of the matching principle and the emphasis on fair value accounting they indicate that a rules based culture makes the audit function centralized and mechanical and hinders the development of audit professionals a summary impression from our work is that cfos view earnings quality as more of a single and unconditional characteristic in contrast to current research where measures of earnings quality are strongly conditional on the decision setting this cfo view is related to their idea of one number a single earnings metric that shapes both their interactions with external stakeholders and internal decision making

persistent private information this paper studies the design of optimal contracts in dynamic environments where agents have private information that is persistent in particular i focus on a continuous time version of a benchmark insurance problem where a risk averse agent would like to borrow from a risk neutral lender to stabilize his utility the agent privately observes a persistent state variable typically either income or a taste shock and he makes reports to the principal i give verifiable sufficient conditions showing that incentive compatible contracts can be written recursively conditioning on the report and two additional state variables the agent s promised utility and promised marginal utility of the private state i then study two examples where the optimal contracts can be solved in closed form showing how persistence alters the nature of the contract unlike the previous discrete time models with independent and identically distributed i i d private information the agent s consumption under the contract may grow over time furthermore in my setting the efficiency losses due to private information increase with the persistence of the private information and the distortions vanish as i approximate an i i d environment

optimal control of a production inventory system with productreturns abstract we consider a production inventory system that consists of n stages each stage has a finite production capacity modelled by an exponential server the downstream stage faces a poisson demand each stage receives returns of products according to independent poisson processes that can be used to serve demand the problem is to control production to minimize discounted or average holding and backordering costs for the single stage problem n 1 we fully characterize the optimal policy we show that the optimal policy is base stock and we derive an explicit formula for the optimal base stock level for the general n stage problem we show that the optimal policy is characterized by state dependent base stock levels in a numerical study we investigate three heuristic policies the base stock policy the kanban policy and the fixed buffer policy the fixed buffer policy obtains poor results while the relative performances of base stock and kanban policies depend on bottlenecks we also show that returns have a non monotonic effect on average costs and strongly affect the performances of heuristics finally we observe that having returns at the upstream stage is preferable in some situations

examining the leontief paradox in u s agricultural trade abstract factor intensity of united states agricultural trade is examined in the context of leontief s classic paradox using leontief s method as well as methods developed recently by leamer and others findings indicate that factor endowments are important determinants of u s agriculture s comparative advantage in trade as suggested by the heckscher ohlin theory

inventory rationing in a make to stock production system with several demand classes and lost sales this paper considers the stock rationing problem of a single item make to stock production system with several demand classes and lost sales for the case of poisson demands and exponential production times we show that the optimal policy can be characterized by a sequence of monotone stock rationing levels for each demand class there exists a stock rationing level at or below which it is optimal to start rejecting the demand of this class in anticipation of future arrival of higher priority demands a simple queueing model is analyzed to compute the operating cost of a rationing policy in a numerical study we compare the optimal rationing policy with a first come first served policy to investigate the benefit of stock rationing under different operating conditions of the system

the kennedy round evidence on the regulation of international trade in the united states the purpose of this paper is to analyze and provide empirical evidence regarding the regulation of international trade flows our goal is to provide an explanation of the changes in the interindustry pattern of trade restrictions which emerged from the kennedy round of tariff negotiations the principal conclusion of the analysis is that the pattern of protection which resulted from the kennedy round was shaped to minimize the domestic political disruption resulting from liberalization industries which faced significant import threats and whose characteristics enhanced their potential political influence were able to maintain tariff protection in the face of overall liberalization the potential impact of the agreed upon tariff reductions was partially undermined by the introduction of offsetting nontariff trade barriers ntbs in addition ntbs were introduced systematically in industries that were becom

exports and economic growth in industrialized countries the prima facie causal relationships between growth exports and factor inputs capital and labour are investigated in five industrialized countries germany itlay japan united kingdom and united states over the period 1960 87 by analysing a four variable vector autoregressive var model for each country our results indicate that germany and japan experienced export led growth reverse causality between exports and growth is found in the case of the us and uk while to causal relationship between exports and output is found for itlay

the financing of innovation learning and stopping we consider the financing of a research project under uncertainty about the time of completion and the probability of eventual success we distinguish between two financing modes namely relationship financing where the allocation decision of the entrepreneur is observable and arm s length financing where it is unobservable we find that equilibrium funding stops altogether too early relative to the efficient stopping time in both financing modes the rate at which funding is released becomes tighter over time under relationship financing and looser under arm s length financing the tradeoff in the choice of financing modes is between lack of commitment with relationship financing and information rents with arm s length financing

earnings management to avoid earnings decreases and losses this paper provides evidence that firms manage reported earnings to avoid earnings decreases and losses specifically in cross sectional distributions of earnings changes and earnings we lind unusually low frequencies of small decreases in earnings and small losscs and unusually high frequencies of small increases in earnings and small positive income we find evidence that two components of earnings cash flow from operations and changes in working capital are used to achieve increases in earnings we present two theories based on stakeholder use of information processing heuristics and prospect theory about the motivation for avoidance of earnings decreases and losses

testing two trade models in latin american agriculture abstract the heckscher ohlin and markusen models state that countries export the goods intensive in the use of their relatively abundant factor latin american agricultural trade is consistent with both models the paper then shows that latin american agricultural trade is primarily explained by country differences in relative factor abundance between countries rather than differences in technology this findings does not reject the heckscher ohlin model but rejects one of markusen s models

control of a production inventory system with returns under imperfect advance return information we consider a production inventory system with product returns that are announced in advance by the customers demands and announcements of returns occur according to independent poisson processes an announced return is either actually returned or cancelled after a random return lead time we consider both lost sale and backorder situations using a markov decision formulation the optimal production policy with respect to the discounted cost over an infinite horizon is characterized for situations with and without advance return information we give insights in the potential value of this information also some attention is paid to combining advance return and advance demand information further applications of the model as well as topics for further research are indicated

effects of system parameters on the optimal cost and policy in a class of multidimensional queueing control problems we consider a class of markov decision processes frequently employed to model queueing and inventory control problems for these problems we explore how changes in different system input parameter

science and technology in united states foreign trade economists generally believe that modern science technology such as the presence of scientists and engineers or research and development is a central factor in the comparative advantage of advanced industrial nations however most discussion of this topic rests on cross industry regressions which leamer and bowen i981 do not provide a valid indication of factor abundance so the overall role of science still remains to be established in addition much remains to be known about the role of different facets of science and innovation in the process of generating comparative advantage there are two fundamentally different ways of understanding technological differences between countries one point of view adopted in the standard neoclassical theory of international trade assumes all countries are on the same production function under these circumstances relative factor abundance determines the factor services which a country exports or imports within this perspective one can make progress towards an understanding of the role of science and technology in international trade by dividing science into many highly specific narrowly defined input factors calculations can then determine the relative abundance of those inputs associated with science technology versus other input factors in a given country or the relative abundance of different elements within the broad area of overall science technology quite another procedure assumes there are substantial differences in the production possibilities faced by different countries for example krugman i979 recently argued that advantages in innovation and lags in the diffusion of knowledge are the basic influences which permit incomes to be higher in the industrialised world than in developing nations this view illustrates the potential economic significance of innovation in advanced countries since the generation of new technologies in industrialised countries and their diffusion to the rest of the world then essentially determines world income distribution and world economic development however empirical implementation of the diffusion viewpoint requires data for many countries which greatly limits the number of facets of technology which can be considered since the present paper is centrally concerned with the effect which a wide variety of technological elements has on international trade we choose to select a framework within which the ample data available on different aspects of technology in the united states can be utilised the first view of technological

resource supplies and changing world agricultural comparative advantage abstract this paper advances consideration of the heckscher ohlin h o theory of comparative advantage to agriculture in a dynamic setting the dynamic relationship among trade flows resource supplies and factor contents is studied the view that special circumstances in the agricultural sector render the h o theory inapplicable as a guide to agricultural trade is challenged consistent with the h o theory the results suggest that changing world patterns of resource abundance are an important explanation of the evolving structure of world trade in agriculture commodities

r d rivalry industrial policy and u s japanese trade the authors examine how the strategic aspect of japanese research and development expenditures and industrial policies affected u s japanese bilateral trade during the late 1970s and investigate which component of r d expenditures on process innovation product quality improvements new products and new technology or technology transfer proved to be most effective they find that while japanese r d expenditures have generally promoted japan s trade advantage certain components of r d have proved more effective than other the depreciation subsidy and special status with the ministry of international trade and industry is positively related to the japanese trade performance while legal cartelization status has not had any apparent effect copyright 1988 by mit press

free trade fair trade strategic trade and protectionism in the u s congress 1987 88 what conditions led the one hundredth congress of the united states to enact fair trade and strategic trade policies into law during 1987 88 political partisanship is an important force with democrats supporting and republicans opposing all types of trade intervention otherwise the coalitions of support for and opposition to the various trade policies differ particularly in the senate in that body international business is associated with support for fair trade policies and with opposition to classical protectionism while domestic u s business is associated with support for classical protectionism liberalism is strongly associated with support for fair and strategic trade policies but is not associated with classical protectionism in the house of representatives the long standing protectionist coalition remains an influence few forces in support of free trade remain in u s politics changing international market conditions rapidly affect the making of u s trade policy

the impact of technological innovation on international trade patterns the evidence reconsidered abstract this paper presents some new evidence in relation to the role of technical change in particular industrial innovation on the international competitiveness of the various oecd countries its originality consists primarily of a using a technology output indicator to measure technological performance b presenting and comparing various measures of trade and technological performance for each individual oecd country with the exception of iceland c analysing at a relatively high level of product industry disaggregation the relationship between export performance and technological performance at the same time the very limited scope of the paper has to be emphasized a the analysis is purely static all the evidence presented relates to one year 1977 b most of the results obtained are preliminary and should be further substantiated by more detailed empirical and theoretical research c as a consequence little attention has been paid to policy implications which it was felt could only be discussed properly in a later stage the paper consists of four sections a brief review of the state of the art section 1 a discussion on definitions of technology intensity section 2 the development of the best technology output indicator section 3 and the empirical analysis itself section 4 the following most important results emerge from these various sections a there are serious shortcomings in using average technology intensity as bench mark for classifying products or industries in technology intensive or nontechnology intensive categories b there is a substantial difference between technology intensity as measured on the basis of a technology input proxy rd c yet as between countries the most traditional output and input indicators the number of patents granted and the amount spent on rd d foreign patenting in particular foreign patenting in the united states figs 1 and 2 section 3 is a more reliable technology output proxy than domestic patenting e in terms of technological comparative advantage as opposed to technology intensity it is the small oecd countries as opposed to the large ones which seem to base their trade comparative advantage on technological comparative performance table 7 section 4 1 f at the individual industry level it is found that i for most technology intensive industries defined however in a less restrictive way than us r d intensities a close relation exists between technological performance and export performance and ii that as compared to other country specific resource variables technological performance is the most important trade explanatory variable its elasticity increasing with the technology intensity of industries tables 11 and 12 section 4 2 space constraints prevented us from presenting the data in relation to the inter industry and inter country analysis these can however be obtained from the author

influence of dependency between demands and returns in a reverse logistics system we consider two reverse logistics systems where returned products are as good as new for the first system the product return flow is independent of the demand flow we prove that the optimal policy is of base stock type and we establish monotonicity results for the optimal base stock levels with respect to the system parameters arrival rate production rate return rate production cost lost sale cost return cost and holding cost we also provide an efficient algorithm to compute the optimal base stock level for the second system demands and returns are strongly correlated a satisfied demand induces a product return after a stochastic return lead time with a certain probability when the return lead time is null we extend the results obtained for the first system when the return lead time is positive the optimal control problem is more complex and we do not prove that the optimal policy is of base stock type however we provide a framework to analyse base stock policies finally we carry out a numerical study on many scenarios to investigate the impact of ignoring dependency between demands and returns we observe that ignoring this dependency yields to non negligible cost increase