forecasting model of rss3 price in futures market 3 abstract the agricultural futures market affects the rubber price in thailand rubber processors use the agricultural futures market to avoid risks associated with fluctuations in rubber price investors make profits from the difference between the current price and the future price this paper presents the forecasting models for futures price of the natural rubber ribbed smoked sheets no 3 rss3 the results from the most efficient model can inform the decision of investors on buying and selling at the proper time the study employs the least mean squared error as a criterion for the selection of the best prediction model it includes an analysis of factors affecting the rss3 futures prices in thailand s futures market the results show that the previous monthly futures prices and oil prices significantly affected the futures prices in the same direction the net import of natural rubber by japan was the leading indicator for the trend in rubber futures prices in thailand the analytical model was shown to be applicable and would facilitate related studies in forecasting the futures prices of other commodities time series data was found to be suitable for the forecasting model keywords futures price forecasting agricultural futures market

composite forecasting approach application for next day electricity price forecasting abstract accurate forecasting of electricity prices can provide significant benefits to energy suppliers when allocating their assets and to energy consumers for defining an optimal portfolio there are numerous methods that efficiently support the forecasting of time series such as electricity prices which have high volatility however the performance of these approaches varies depending on data sets and operational conditions in this work the concept of composite forecasting is presented and implemented in a retrospective study in real industrial forecasting conditions to show the potential of forecast performance improvement and comparable high consistency of a forecast performance across different day peak and day base electricity price data sets for different seasons as individual methods support vector regression artificial neural networks and ridge regression are implemented the forecast performances of these methods are evaluated and compared with their forecast combination using different error measures the results show that composite forecasting processes with inverse root mean squared error combination approach can generate on average a more accurate and robust forecast than using an individual methods or other combination schemas

integration of discrepant sales forecasts the influence of plausibility inferences based on an evoked range abstract the authors hypothesize that when managers integrate two projections to form a sales estimate they evoke and use a sales range to judge inappropriately the plausibility of each projection this judged plausibility as well as the margin of error based on the market research company s typical accuracy is used to assign weights to each projection five experiments find strong evidence for this process and demonstrate a resulting bias

the behavior of prices in the nikkei spot and futures market abstract we examine the relation between the prices of japanese stocks traded on the tokyo stock exchange tse as reflected in the nikkei stock average nsa stock index and the prices of the nsa futures contract traded on the singapore international monetary exchange simex since the inception of trading in september 1986 the nsa futures contract has generally sold at a discount relative to its theoretical value trading restrictions and transaction costs may explain some of this mispricing which has been declining over time as in the u s markets

combining day ahead forecasts for british electricity prices abstract this paper considers how well the approach of combining forecasts extends to the context of electricity prices with the increasing popularity of regime switching and time varying parameter models for predicting power prices the multi model and evolutionary considerations that usually support the combining of simpler time series methods may be less applicable when the individual models incorporate these features we address this question with a backtesting analysis on british day ahead prices furthermore given the volatility of power prices and concerns about accurate forecasting under extreme price excursions we evaluate the results using various error metrics including expected shortfall the comparisons are furthermore carefully simulated to consider model selection uncertainty in order to realistically test the value of combining as an ex ante policy overall our results support combining for both accurate operational planning and risk management

which dreams come true endogeneity industry structure and forecasting accuracy forecasts are plentiful accurate long range forecasts are rare but some forecasts are more accurate than others are and a few are very accurate in this paper we first explore the case of moore s law a forecast that has proven quite accurate for almost 40 years we illustrate how expectations that moore s law will continue to be accurate actually make it accurate based on the insights of this case we hypothesize that two factors facilitate such self fulfilling forecasts and so make accuracy more possible we test these hypotheses on a set of 3142 forecasts about us manufacturing industries during the 1970s we find that high industry concentration and high control over the predicted variable tend to increase the accuracy of forecasts copyright 2003 oxford university press

forming coalitions and the shapley ntu value a simple protocol for coalition formation is presented first an order of the players is randomly chosen then a coalition grows by sequentially incorporating new members in this order the protocol is studied in the context of non transferable utility ntu games in characteristic function form if weighted utility transfers are feasible when everybody cooperates then the expected subgame perfect equilibrium payoff allocation anticipated before any implemented game is the shapley ntu value

the effectiveness of alternative preference elicitation procedures in predicting choice in a large scale national study the authors evaluated the effectiveness of several preference elicitation techniques for predicting choices the criteria for accuracy included both individual hit

preferences over solutions to the bargaining problem there are several solutions to the nash bargaining problem in the literature since various authors have expressed preferences for one solution over another we find it useful to study preferences over solutions in their own right we identify a set of appealing axioms on such preferences that lead to unanimity in the choice of solution which turns out to be the solution of nash

combining economic forecasts a method for combining forecasts may or may not account for dependence and differing precision among forecasts in this article we test a variety of such methods in the context of combining forecasts of gnp from four major econometric models the methods include one in which forecasting errors are jointly normally distributed and several variants of this model as well as some simpler procedures and a bayesian approach with a prior distribution based on exchangeability of forecasters the results indicate that a simple average the normal model with an independence assumption and the bayesian model perform better than the other approaches that are studied here

the nash bargaining solution is optimal abstract we consider the problem faced by players in a two person bargaining game who have different opinions about what is the appropriate solution concept to use a procedure is proposed to resolve such a conflict and it is shown that the nash bargaining solution constitutes the unique equilibrium of the game induced by the procedure as a by product we obtain that in the axiomatic characterization of the nash solution the controversial independence of irrelevant alternatives axiom can be replaced by a much weaker recursivity axiom which amounts to requiring independence of alternatives that cannot be obtained as an outcome of a risk sensitive solution

forecaster diversity and the benefits of combining forecasts the expected error variance of a combined forecast is necessarily lower than that of an individual forecast but in practice there may be considerable variation around these expected values this paper introduces a measure of the benefit from combining the probability of a reduction in error variance which recognizes this problem the measure is applied to data on the forecasts and forecasting methods of a panel of u s economists to determine how the benefits of combining vary with the number of forecasts combined and with the diversity in theories and techniques among the component forecasts

marketing information a competitive analysis selling information that is later used in decision making constitutes an increasingly important business in modern economies jensen jensen fred o 1991 information services congram friedman eds the ama handbook of marketing for the service industries chapter 22 ama com new york 423 443 information is sold under a large variety of forms industry reports consulting services database access and or professional opinions given by medical engineering accounting financial and legal professionals among others this paper is the first attempt in marketing to study competition in the rapidly emerging information sector specifically we are interested in answering the following questions 1 is competition fundamentally different when competing firms sell information rather than traditional goods and services and if yes why 2 what are the implications of such differences for decision makers marketers and regulators 3 can we explain some of the observed marketing strategies in the information industry as such the audience of the paper includes academics as well as professionals who are interested in understanding what is specific about competition in information markets familiarity with the practical implications of such differences and understanding of the mechanisms that drive them is essential for those who are faced with the problem of marketing information to answer the above research questions we build a simple game theoretic model that consists of two firms selling information to a population of consumers who are heterogeneous in their willingness to pay for the quality of information the most important features of the model are the following information products sold by the two firms are modeled as random draws from two normal distributions having equal mean the variances of these distributions and their correlatedness constitute the product attribute space which is assumed to be common knowledge consumers are interested in assessing the mean of the distributions and to do so they can buy the sample from any of the firms or they can buy both samples and combine them to obtain a more accurate estimate quality of information is linked to the accuracy of consumers estimate of the mean which in turn is influenced by the accuracy of each sample as well as by their correlatedness consumers utility depends on the quality of information they purchased on their inherent utility for quality taste and on the total price they paid to acquire information knowing consumer preferences firms simultaneously price their information products the main finding of the paper is that information markets face unique competitive structures in particular the qualitative nature of competition changes depending on basic product characteristics while traditional products and services compete either as substitutes or as complements in the relevant product attribute space information may be one or the other depending on its position within the same product attribute space said differently the nature of competition changes qualitatively with a continuous change in basic product attribute levels the intuition behind this finding is the following when purchasing information consumers facing important decisions may find it beneficial to purchase from several information sellers this is more likely to happen when the reliability of information is low and the sources of information are independent under such conditions information products tend to be complements and as a result competition between sellers is relatively mild in the opposite case when information is reliable and or sellers sources are highly correlated consumers are satisfied after consulting a single source in this case information products are substitutes and sellers tend to undercut one another s prices to induce consumers to choose their brand understanding this discontinuity in competitive structures has important implications for decision makers as very different strategies are optimal under different product characteristics under substitution traditional strategies to avoid competition e g differentiation are recommended when the competing products reliability is generally low they are complements firms are better off accommodating competition in fact we find that a firm may benefit from inviting a competitor finally our findings are also important for regulators of information markets as the literature on complementarity suggests price fixing agreements between firms offering complementary products may benefit firms as well as consumers

forecasting with temporal hierarchies this paper introduces the concept of temporal hierarchies for time series forecasting a temporal hierarchy can be constructed for any time series by means of non overlapping temporal aggregation predictions constructed at all aggregation levels are combined with the proposed framework to result in temporally reconciled accurate and robust forecasts the implied combination mitigates modelling uncertainty while the reconciled nature of the forecasts results in a unified prediction that supports aligned decisions at different planning horizons from short term operational up to long term strategic planning the proposed methodology is independent of forecasting models it can embed high level managerial forecasts that incorporate complex and unstructured information with lower level statistical forecasts our results show that forecasting with temporal hierarchies increases accuracy over conventional forecasting particularly under increased modelling uncertainty we discuss organisational implications of the temporally reconciled forecasts using a case study of accident emergency departments

perfect equilibria in a model of bargaining with arbitration abstract we consider an alternating offer bargaining model in which the players may agree to call in an arbitrator in case of disagreement the main message of our study is that the mere presence of an arbitrator who can only become active with the consent of both parties in the background of negotiations may entirely drive their outcome we compare our results with those obtained in models with outside options journal of economic literature classification number c78

trade wars trade negotiations and applied game theory what is the value of trade negotiations quantitative measures of the value of trade liberalisation generally ignore the strategic aspects of protection policy the traditional approach is to compare welfare levels under the existing structure of protection with welfare levels under some alternative structure of protection such as unilateral or multilateral free trade we add two additional questions first in a non cooperative context are either of these points of comparison consistent with countries adopting best response policies given the policies of other countries second in the context of a cooperative negotiation are either of these points of comparison consistent with the outcome that meets certain plausible criteria for a bargaining process if the answer to either of these questions is no then the traditional approach provides at best an incomplete answer to the original question and could provide a misleading answer a simple example illustrates our basic point consider the game in table i this is a non cooperative game between the united states and ec in which each agent has just two pure strategies to do nothing and keep k the existing structure of protection in place or to abolish a trade barriers on imports from the other agent only the payoffs shown are the annual welfare impact relative to the status quo as measured by the equivalent variation ev in income in billions of i973 u s dollars the values shown are taken from the simulation results of brown and whalley i980 table i 4 p 864 what is the best response of the united states in this context if the ec decides to keep its protection structure the united states does better by also keeping its protection structure intact in other words given that the ec plays k it is a best response for the united states to also play k thus the traditional approach would imply that the united states gains from protection in this case however what is the best response of the united states if the ec decides to abolish its protection structure in this instance the united states does best by also abolishing its protection structure the point here is simply that the welfare cost of protection to the united states depends on what the ec does without saying something about what the ec will do one cannot answer our question vis a vis the united states as it happens in this particular game we

intraday volatility in international stock index futures markets meteor showers or heat waves the international transmission of intraday price volatility among the united states united kingdom and japanese stock index futures markets in the period 1988 1994 is investigated in this paper the empirical results based on extreme value estimators and vector autoregression indicate the rapid transmission of information between markets the volatilities of the u s and u k futures markets appear to follow a meteor shower rather than a heat wave type of process this means that these volatilities react to shocks from other markets i e they cannot be described only by their past values however the heat wave hypothesis is not rejected for the japanese market meaning that the shocks to japanese volatility are mostly country specific a multivariate garch model supports the u k and japanese but not the u s results

automated earnings forecasts beat analysts or combine and conquer prior studies attribute analysts forecast superiority over time series forecasting models to their access to a large set of firm industry and macroeconomic information an information advantage which they use to update their forecasts on a daily weekly or monthly basis a timing advantage this study leverages recently developed mixed data sampling midas regression methods to synthesize a broad spectrum of high frequency data to construct forecasts of firm level earnings we compare the accuracy of these forecasts to those of analysts at short horizons of one quarter or less we find that our midas forecasts are more accurate and have forecast errors that are smaller than analysts when forecast dispersion is high and when the firm size is smaller in addition we find that combining our midas forecasts with analysts forecasts systematically outperforms analysts alone which indicates that our midas models provide information orthogonal to analysts our results provide preliminary support for th

aggregating subjective forecasts some empirical results the impact on forecast accuracy of aggregating the subjective forecasts of up to 13 individuals was examined for five forecast weighting methods equal weighting two ex post methods that took advantage of prior information about the individuals relative accuracy and two ex ante methods based on objective and subjective assessments of relative accuracy the individuals were executives managers and sales personnel employed by time inc and the variable forecasted was the number of advertising pages sold annually by time magazine over a 14 year period the results show that both the average forecast error and the variance of the error decrease as additional individuals forecasts are included in the aggregate only two to five individuals forecasts must be included to achieve much of the total improvement available from combining all 13 forecasts three of the differential weighting methods produced more accurate forecasts than equal weighting but the magnitude of the improvement was small implications for realistic forecasting situations are discussed as are conditions under which the use of aggregates seems attractive

quadratic social welfare functions john harsanyi has provided an intriguing argument that social welfare can be expressed as a weighted sum of individual utilities his theorem has been criticized on the grounds that a central axiom that social preference satisfies the independence axiom has the morally unacceptable implication that the process of choice and considerations of ex ante fairness are of no importance this paper presents a variation of harsanyi s theorem in which the axioms are compatible with a concern for ex ante fairness the implied mathematical form for social welfare is a strictly quasi concave and quadratic function of individual utilities

averages of forecasts some empirical results an alternative to using a single forecasting method is to average the forecasts obtained from several methods in this paper we investigate empirically the impact of the number and choice of forecasting methods on the accuracy of simple averages it is concluded that the forecasting accuracy improves and that the variability of accuracy among different combinations decreases as the number of methods in the average increases thus combining forecasts seems to be a reasonable practical alternative when as is often the case a true model of the data generating process or a single best forecasting method cannot be or is not for whatever reasons identified

probabilistic decision model of wind power investment and influence of green power market this paper presents results from a model of a representative wind power investor s decision making process using a monte carlo simulation of a project financial analysis data in the form of probability distribution functions pdfs for key input variables were collected from interviews with investors and other professionals active in the u s wind power industry using a formal expert elicitation protocol this study presents the first quantitative estimates of the effect of the u s voluntary renewable energy certificate rec market on renewable energy generation the results indicate that the investment decisions of wind power project developers in the united states are unlikely to have been altered by the voluntary rec market the problem with the current voluntary rec market is that it does not offer developers a reliable risk adjusted revenue stream consequently the claims by u s green power retailers and promoters that voluntary market recs result in additional wind power projects lack credibility even dramatic increases in voluntary market rec prices in the absence of long term contracts were found to have only a small effect on investor behavior

robust min max portfolio strategies for rival forecast and risk scenarios we consider an extension of the markowitz mean variance optimization framework to multiple return and risk scenarios it is well known that asset return forecasts and risk estimates are inherently inaccurate the method proposed provides a means for considering rival representations of the future the optimal portfolio is computed simultaneously with the worst case to take account of all rival scenarios this is a min max strategy which is essentially equivalent to a robust pooling of the scenarios robustness is ensured by the noninferiority of min max for example a basic worst case optimal return is guaranteed in view of multiple return scenarios if robustness happens to have too high a cost guided by the min max pooling it is also possible to explore other pooling alternatives a min max algorithm is used to solve the problem and illustrate the robust character of min max with return and risk scenarios we study the properties of the min max risk return frontier and compare with the potentially suboptimal worst case where the investment strategy and the worst case are computed separately 2000 elsevier science b v all rights reserved jel classixcation c44 c61 c63 g11

on the interpretation of the nash bargaining solution and its extension to non expected utility preferences the paper reexamines the foundations of the axiomatic nash bargaining theory more specifically it questions the interpretation of the nash bargaining solution and extends it to a family of non expected utility preferences a bargaining problem is presented as x d 2 where x is a set of feasible agreements described in physical terms d is the disagreement event and 1 and 2 are preferences defined on the space of lotteries in which the prizes are the elements in x and d the ordinal nash bargaining solution is defined as an agreement y satisfying for all p e 0 1 and for all x e x if px 1 y then py 2 x and if px 2 y then py x where px is the lottery which gives x with probability p and d with probability 1 p revisions of the pareto symmetry and iia axioms characterize the ordinal nash bargaining solution in the expected utility case this definition is equivalent to that of the nash bargaining solution however this definition is to be preferred since it allows a statement of the nash bargaining solution in everyday language and makes possible its natural extension to a wider set of preferences it also reveals the logic behind some of the more interesting results of the nash bargaining solution such as the comparative statics of risk aversion and the connection between the nash bargaining solution and strategic models

consensus forests of corporate earnings analysts forecasts and time series methods an alternative to using a single forecasting method is to average the forecasts made by various methods in this paper we examine empirically combinations of financial analysts forecasts and forecasts from time series methods in order to predict corporate earnings per share we conclude that on average the primary forecasting advantages of analysts over time series methods based on annual data appear to occur over short forecast horizons less than a year neither analysts nor other time series methods substantially outperform a random walk prediction of no change when forecasts are made near the beginning of the fiscal year for predictions in the first half of the fiscal year there is evidence of forecasting benefits from combining time series and analysts forecasts especially if there are few analysts forecasts

average of forecasts an improvement stein rules are used in forming combination forecasts such forecasts have smaller prediction risk under certain conditions than the preferred method of average of forecasts the new composite forecasts will be theoretically biased but are likely to have smaller mean squared error of forecasts as shown in the empirical exercises examined when the forecasts appear to be unbiased and have a common mean lindley type combination is most useful

arbitrage opportunities in the japanese stock and futures markets 1990 arbitrage opportunities in the japanese stock and futures markets financial analysts journal vol 46 no 2 pp 14 24

the averaging mechanism abstract we consider two person bargaining games and we assume that the agents want to apply two possibly different bargaining solutions problems arise if the allocations chosen by these bargaining solutions do not coincide we propose a mechanism which mimics a step by step bargaining procedure in order to resolve such a conflict and give a characterization of the mechanism

stock index futures arbitrage in finland theory and evidence in a new market abstract this paper examines the pricing of stock index futures contracts on the new finnish market the striking feature of the finnish market is that there is no institutional framework for short selling of stocks this has been suggested to be the most important reason for the underpricing futures contracts persistent mispricing would however imply that also early and delayed unwindings have value which increases the arbitrage profits several rollover profits are reported in this study this suggest that current stock owners have not yet begun trading on the finnish futures market on a large scale

commitment and conflict in bilateral bargaining building on crawford 1982 we study a model of bilateral bargaining in which negotiators can make binding commitments at a low positive cost c our primary solution concept is iterated strict dominance if commitment attempts never fail there are three solutions in two solutions all the surplus goes to one player in the third solution there is a high probility of con ict if commitment attempts succeed with probability q 1 the unique solution entails con ict with probability q 2 when c 0 analogous results hold if the requirement of iterated strict dominance is replaced by iterated weak dominance

nash equilibria of over the counter bargaining for insurance risk redistributions the role of a regulator this paper proposes a way to optimally regulate bargaining for risk redistributions we discuss the strategic interaction between two firms who trade risk over the counter in a one period model novel to the literature we focus on an incomplete set of possible risk redistributions this keeps the set of feasible contracts simple we consider catastrophe and longevity risk as two key examples the reason is that the trading of these risks typically occurs over the counter and that there are no given pricing functions if the set of feasible strategies is unconstrained we get that all nash equilibria are such that no firm benefits from trading a way to avoid this is to restrict the strategy space a priori in this way a nash equilibrium that is interesting for both firms may exist the intervention of a regulator is possible by restricting the set of feasible strategies for instance a firm has to keep a deductible on its prior risk we characterize optimal regulation by means of nash bargaining solutions

short sale restrictions implications for stock index arbitrage abstract this paper offers a study of relevant transaction costs when examining the efficiency of stock index futures markets we suggest that a different transaction cost estimate should be used when testing the upper side of the cost of carry model than when testing the lower side of the model empirical evidence indicates that this explains most of the underpricing observed in the finnish stock index futures market

robustness of intermediate agreements and bargaining solutions abstract most real life bargaining is resolved gradually during this process parties reach intermediate agreements these intermediate agreements serve as disagreement points in subsequent rounds we identify robustness criteria which are satisfied by three prominent bargaining solutions the nash proportional and as a special case to the egalitarian solution and discrete raiffa solutions we show that the robustness of intermediate agreements plus additional well known and plausible axioms provide novel axiomatizations of the above mentioned solutions hence we provide a unified framework for comparing these solutions bargaining theories

index futures arbitrage and the behavior of stock index futures prices this article examines intraday transaction datafor s p 500 stock indexfutures prices and the intraday quotes for the underlying index the data indicate that thefutures price changes are uncorrelated and that the variability of these price changes exceeds the variability ofprice changes in the s p 500 index this excess variability of the futures over the index remains even after controlling for the nonsynchronous prices in the index quotes which induces autocorrelation in the index changes we advance and examine empirically two hypotheses regarding the difference between the futures price and its theoretical value that this mispricing increases on average with maturity and that it is path dependent evidence supporting these hypotheses is presented

scaling heuristics shape technology should economic theory take notice in some economics textbooks production theory is developed axiomatically the divisibility axiom presents a bold affront to realism it distorts the static theory and forecloses some potential encounters with technological change the article reviews propositions about geometrical scaling that have long been recognized as relevant to the realities studied in many fields including industrial organization economics the article concludes by sketching a program of reform for production theory that would make connections to dosi s concepts of technological paradigms and trajectories dosi 1982

the relative profitability of nash bargaining on the labour demand curve or the contract curve abstract given the nash bargaining solution with parametric bargaining strengths and threat points it is shown that profits are often higher if the bargaining agenda between a union and a single firm or two unions and cournot duopolists excludes employment

a bargaining model of farrell inefficiency abstract an enormous number of empirical papers have estimated technical efficiency the distance of firms inside a frontier following the model of farrell farrell 1957 the measurement of productive efficiency journal of the royal statistical society series a 120 3 253 290 we propose a theory that explains the distance these empirical papers seek to measure the theory is based on the idea that workers can bargain low effort high crew sizes etc if they and the firm have some monopoly power we provide simple theoretical expressions for the empirical measures of technical and allocative efficiency and compare them to those in the statistical literature we also consider the relation between competition and efficiency

collusion among asymmetric firms the case of different discount factors abstract this study investigates collusive behavior among asymmetric firms for this purpose we develop a selection criterion for deriving a unique collusive outcome and apply it to the case when firms have different discount factors our analysis reveals that for collusion to be self enforcing it is unnecessary that all firms have sufficiently high discount factors but rather only that firms on average have a sufficiently long run view the optimal collusive outcome entails a strict ordering of output quotas in which firms with relatively low discount factors receive a disproportionate share of market demand as found in the case of a common discount factor a fall in a firm s discount factor reduces the likelihood of successful collusion this effect reduces firm profits on the other hand in the event that firms can collude a lowering of a firm s discount factor increases its output quota so that its profits rise

the value of combining forecasts in inventory management a case study in banking managing inventories in the face of uncertain stochastic demand requires an investment in safety stocks these are related to the accuracy in forecasting future demands and the noise in the demand generation process reducing the demand forecasting error can free up capital and space and reduce the operating costs of managing the inventories a leading bank in hong kong consumes more than three hundred kinds of printed forms for its daily operations a major problem of its inventory control system for the forms management is to forecast the monthly demand of these forms in this study the idea of combining forecasts is introduced and its practical application is addressed the individual forecasts come from well established time series models and the weights for combination are estimated with quadratic programming the combined forecast is found to perform better than any of the individual forecasts

tourism forecasting to combine or not to combine abstract existing non tourism related literature shows that forecast combination can improve forecasting accuracy this study tests this proposition in the tourism context by examining the efficiency of combining forecasts based on three different combination methods the data used for this study relate to tourist arrivals in hong kong from the top ten tourism generating countries regions the forecasts are derived from four different forecasting models autoregressive integrated moving average arima model autoregressive distributed lag model adlm error correction model ecm and vector autoregressive var model all forecasts are ex post and the empirical results show that the relative performance of combination versus single model forecasts varies according to the origin destination tourist flow under consideration which parallels previous findings regarding the relative performance of individual forecasting methods the results also vary with the combination techniques used furthermore although the combined forecasts do not always outperform the best single model forecasts almost all the combined forecasts are not outperformed by the worst single model forecasts this suggests that forecast combination can considerably reduce the risk of forecasting failure this conclusion also implies that combined forecasts are likely to be preferred to single model forecasts in many practical situations

unstable weights in the combination of forecasts the weights used in the combination of forecasts are shown to be very unstable they are generally so unstable that the combined forecasts often do not perform better than some of the individual forecasts or a simple average of the forecasts in practice the instability is found from a series of monte carlo experiments as well as from the nominal gnp forecasts from four well known macro forecasters the monte carlo experiments also show that when the underlying models are known a composite forecast from a composite model is generally more accurate than the combination of the individual forecasts a simple average is shown to be the best technique to use in practice because the weights in the combination are so unstable

the accuracy of combining judgemental and statistical forecasts judgement based forecasts are widely used in practice either alone or in conjunction with computer prepared forecasts this study empirically examines the improvement in accuracy which can be gained from combining judgemental forecasts either with other judgemental or with quantitatively derived forecasts two judgemental forecasting approaches are used by each of two different groups in a laboratory setting to give four sets of judgemental forecasts for the 68 monthly time series of the m competition these are combined either with each other or with forecasts from deseasonalised single exponential smoothing combined forecasts are found to be more accurate than single forecasts with the greatest benefit realised at short forecast horizons and for easier as opposed to harder forecast series averaging was observed to be a far better way of combining judgemental forecasts than a judgemental nonsystematic combination

a meta allocation mechanism in cooperative bargaining abstract we analyze an iterative meta allocation mechanism the minimal agreement procedure which can be used to resolve bargaining conflicts generated by players proposal of differing solution concepts in two person cooperative bargaining at each stage of the iteration our procedure improves the disagreement point so that its limit is on the pareto frontier

the saga of the first stock index futures contract benchmarks models and learning in the presence of imperfect or perturbed benchmarks pricing based on relative valuation or arbitrage can be affected adversely this study highlights persistent pricing irregularities in the kansas city value line kcvl stock index futures market this contract is especially interesting because the underlying benchmark underwent a midstream change in definition from a complex equally weighted geometric index to an equally weighted arithmetic index empirical analysis reveals that during a four year period the market displayed herd like behavior and priced the kcvl geometric contract using the simple but wrong cost of carry benchmark model a dramatic change occurs around the publication of the eytan harpaz 1986 model when the market turns efficient from the perspective of this new model the market appears to have succumbed initially to a bad information cascade primarily because arbitrage was difficult to understand and carry out under complex benchmarking the evidence provides empirical extension to the observational social learning paradigms of simon 1955 banerjee 1992 and bikhchandani hirshleifer and welch 1992 that lead to behavioral herding and information cascades

search wage bargains and cycles in this paper i describe an equilibrium model of job matchings with perfect foresight that has the following property the number of people looking for work changes temporarily when there is a temporary shock to the value of labour s marginal product it does not change when the shock is permanent by contrast real wages change temporarily by a small amount when the shock is temporary but change permanently and by a bigger amount when the shock is permanent thus the model offers an explanation for the observation that over the cycle small wage changes are associated with changes in unemployment whereas secularly wage growth does not seem to affect the rate of unemployment the two most common explanations for this observation in the literature the phelps lucas misperceptions model and the lucas rapping intertemporal substitution model are well grounded in equilibrium theory but they have not stood up well to empirical testing the misperceptions model requires more ignorance of aggregate changes than can be reasonably assumed whereas the intertemporal substitution model requires bigger wage elasticities of labour supply than those estimated in the model of this paper neither misperceptions nor changes in the supply of labour play a role in generating the unemployment cycle all agents observe the shocks when they occur and they anticipate correctly the economy s adjustment path but like the new classical explanations of the cycle the model is an equilibrium one in the sense that all private gains from trade are fully exploited at all phases of the cycle although the social gains from trade may not be fully exploited because of search externalities the cycle i derive here is not due to externalities unlike other related perfect foresight models such as diamond s 1982a the structure of the model is such that the externalities do not give rise to multiple equilibria the key element of the model which is responsible for the transmission of output shocks to unemployment is the equation for wages in markets where the allocation of jobs takes place through search both firms and workers have some monopoly power a point emphasised by mortensen 1970 though he attributed only temporary monopoly power and only to firms i use the nash bargaining solution to solve for the equilibrium wage rate and show that the firm s and worker s alternative returns threat points or

the determination of price and output quotas in a heterogeneous cartel applying a selection criterion that uses both subgame perfection and the nash bargaining solution this paper investigates the relationship between firms cost functions and collusive behavior it is found that the optimal collusive price exceeds the price that the low cost firm would set if it was a monopolist comparative statics reveal that the optimal collusive price is increasing in the low cost firm s unit cost but is decreasing in the high cost firm s unit cost when the cost differential between firms is sufficiently large copyright 1991 by economics department of the university of pennsylvania and the osaka university institute of social and economic research association

the pricing of japanese equity warrants discrepancies between the black scholes value of japanese equity warrants and their observed prices are explained in part by the stochastic volatility of changes in prices of the underlying stocks we fit garch and egarch models to the stochastic volatility and briefly compare their performance to the cev model a hopscotch algorithm is used to value the warrants in the presence of the stochastic stock price volatility the stochastic volatility hopscotch warrant values still differ substantially from corresponding prices in contrast away from the money short term nikkei 225 options valued with the same stochastic volatility models are close to observed prices a regression model is used to fit the differences between warrant values and prices as a function of proxies for market impediments

optimal regulation and country size this paper studies the relationship between country size and the optimal regulatory policy of firms with market power derived from research and development in equilibrium smaller countries allow less exploitation of market power by innovating firms because smaller countries are more able to free ride upon the incentives to research and development afforded by larger countries the free rider problem implies that the nash equilibrium in government policies is inefficient thus there is an incentive for governments to coordinate their policies finally the model is used to explain past and present regulation of the pharmaceutical industry in canada this paper studies the relationship between country size and the optimal regulatory policy of firms with market power derived from research and development in equilibrium smaller countries allow less exploitation of market power by innovating firms because smaller countries are more able to free ride upon the incentives to research and development afforded by larger countries the free rider problem implies that the nash equilibrium in government policies is inefficient thus there is an incentive for governments to coordinate their policies finally the model is used to explain past and present regulation of the pharmaceutical industry in canada

a proposal to unify some concepts in the theory of fairness so far the theory of distributive justice has tried to single out a unique criterion of justice in our opinion we live in a world in which different people hold conflicting ideas about justice we propose a procedure for representing these individual opinions by means of what we call aspiration functions and we present in this paper three different ways of aggregating such opposing opinions into a socially acceptable judgement furthermore we show that many well known concepts are special cases of our approach we study under a restriction on the form of the aspiration functions the conditions that are necessary and sufficient for a social choice correspondence to be generated from any of our concepts

endogenous public sector budgeting to centralize or not in this paper the impact of budget size on a government s choice to centralize or decentralize the budgetary process is investigated using asymmetric information differing preferences and endogenous budgetary arrangements the central government chooses between a budgetary process that excludes the regional board centralization and one that includes the board decentralization in the determination of program budget levels it is predicted that the central government will decentralize the budgetary process at low and centralize at high overall budget levels switching from decentralization to centralization is predicted to

forecasting aggregate retail sales the case of south africa abstract forecasting aggregate retail sales may improve portfolio investors ability to predict movements in the stock prices of retail chains this paper uses 26 23 single and 3 combination forecasting models to forecast south africa s aggregate seasonal retail sales we use data from 1970 01 2012 05 with 1987 01 2012 05 as the out of sample period unlike the previous literature on retail sales forecasting we not only look at a wide array of linear and nonlinear models but also generate multi step ahead forecasts using a real time recursive estimation scheme over the out of sample period to better mimic the practical scenario faced by economic agents making retailing decisions in addition we deviate from the uniform symmetric quadratic loss function typically used in forecast evaluation exercises by considering loss functions that overweight the forecast error in booms and recessions focusing on the results of single models alone shows that their performances differ greatly across forecast horizons and for different weighting schemes with no unique model performing the best across various scenarios however combination forecast models especially the discounted mean square forecast error method which weighs current information more than past not only produced better forecasts but were also largely unaffected by business cycles and time horizons this result along with individual nonlinear models performing better than linear models led us to conclude that theoretical research on retail sales should look at developing dynamic stochastic general equilibrium models that not only incorporate learning behavior but also allow the behavioral parameters of the model to be state dependent to account for regime switching behavior across alternative states of the economy