disagreement in bargaining an empirical analysis of opec abstract we consider a stylised model in which two cartel members bargain over the aggregate production quota in a world of asymmetric information we show that when the two cartel members are sufficiently different the probability of agreement depends on both the current state of demand and initial production specifically the probability of agreement is much lower when demand is low and initial production is relatively high than when demand is high and initial production is relatively low we also find that regardless of the current demand state the more extreme is initial production the higher is the probability of agreement using an event study where we take as events opec production quota announcements we demonstrate empirically that the predictions of the model are borne out

international evidence on crude oil price dynamics applications of arima garch models abstract we examine the usefulness of several arima garch models for modeling and forecasting the conditional mean and volatility of weekly crude oil spot prices in eleven international markets over the 1 2 1997 10 3 2009 period in particular we investigate the out of sample forecasting performance of four volatility models garch egarch and aparch and figarch over january 2009 to october 2009 forecasting results are somewhat mixed but in most cases the aparch model outperforms the others also conditional standard deviation captures the volatility in oil returns better than the traditional conditional variance finally shocks to conditional volatility dissipate at an exponential rate which is consistent with the covariance stationary garch models than the slow hyperbolic rate implied by the figarch alternative

breaks and outliers when modelling the volatility of the u s stock market this study analyses volatility persistence of the u s stock market after taking into account the role of breaks and outliers by employing a wavelet based algorithm it identifies several outliers which are comfortably associated with major events such as the black monday and the asian crisis there is also evidence of clustering of breaks and a substantial variation in the properties of the identified segments

hedging with crop yield futures a mean variance analysis this investigation into the use of new chicago board of trade yield futures to manage price and yield risks shows that a risk minimizing firm can reduce its variance of profit by hedging in both markets compared to hedging in price futures only the greater the variance of the contract underlying yield the less effective the two instrument hedge hedging effectiveness of the dual strategy also depends on the price and yield bases and the effect of a change in either basis depends on whether the established crop yield futures position is short or long

undominated nash implementation in bounded mechanisms we study implementation in undominated nash equilibrium by bounded mechanisms an undominated nash equilibrium is a nash equilibrium in which no agent uses a weakly dominated strategy a mechanism is bounded if every dominated strategy is dominated by some undominated strategy we identify necessary conditions and sufficient conditions for such implementation these conditions are satisfied in virtually all economic environments and are also satisfied by interesting correspondences from the social choice literature for economic settings we provide a particularly simple implementing mechanism for which the undominated equilibrium outcomes coincide with those obtained from the iterative elimination of weakly dominated strategies

oil and the macroeconomy since world war ii all but one of the u s recessions since world war ii have been preceded typically with a lag of around three fourths of a year by a dramatic increase in the price of crude petroleum this does not mean that oil shocks caused these recessions evidence is presented however that even over the period 1948 72 this correlation is statistically significant and nonspurious supporting the proposition that oil shocks were a contributing factor in at least some of the u s recessions prior to 1972 by extension energy price increases may account for much of post opec macroeconomic performance

coordinating development can income based incentive schemes eliminate pareto inferior equilibria individuals inability to coordinate investment may significantly constrain economic development in this paper we study a simple investment game characterized by multiple equilibria and ask whether an income based incentive scheme can uniquely implement the high investment outcome a general property of this game is the presence of a crossover investment point at which an individual s incomes from investment and noninvestment are equal we show that arbitrarily small errors in the government s knowledge of this crossover point can prevent unique implementation of the high investment outcome we conclude that informational requirements are likely to severely limit a government s ability to use income based incentive schemes as a coordination device

long memory and structural changes in the forward discount an empirical investigation abstract we analyze the evidence for long memory and structural changes in the five g7 countries forward discount we establish evidence for long memory by estimating the long memory parameter without allowing for structural breaks we also document evidence for multiple structural breaks in the mean of the forward discount we then adjust for structural changes in the forward discount rate and re estimate the long memory parameter after removing the breaks we still find evidence of stationary long memory in each country s forward discount

a state space forecasting approach to optimal intertemporal cross hedging cross commodity hedging between fishmeal and soybean meal is investigated the approach uses successively updated out of sample forecasts to approximate subjective price expectations and forecast error variance covariance matrices to measure risk forecasts are generated by state space models of vector valued time series in a stationary environment uncertainty reduces to the difference between the historical autocovariance of the random process and the variance covariance of out of sample forecasts results indicate that weakly risk averse agents can increase average marketing returns within acceptable risk levels by combining information from price forecasting models with an appropriate hedging strategy

arch models properties estimation and testing abstract the aim of this survey paper is to provide an account of some of the important developments in the autoregressive conditional heteroskedasticity arch model since its inception in a seminal paper by engle 1982 this model takes account of many observed properties of asset prices and therefore various interpretations can be attributed to it we start with the basic arch models and discuss their different interpretations arch models have been generalized in different directions to accommodate more and more features of the real world we provide a comprehensive treatment of many of the extensions of the original arch model next we discuss estimation and testing for arch models and note that these models lead to some interesting and unique problems there have been numerous applications and we mention some of these as we present different models the paper includes a glossary of the acronyms for the models we describe

implementing coordinated team play abstract this note studies a moral hazard model of joint production in which there are strong gains to coordination the mechanism we propose for resolving the tacit collusion problem that arises in our setting makes use of at will contracts which provide the agents with the option to quit at any time journal of economic literature classification numbers c72 d82

estimating garch volatility in the presence of outliers garch volatilities depend on the unconditional variance which is a non linear function of the parameters consequently they can have larger biases than estimated parameters using robust methods to estimate both parameters and volatilities is shown to outperform maximum likelihood procedures

designing optimal crop revenue insurance when the indemnity schedule is contingent on the farmer s price and individual yield an optimal crop revenue insurance contract depends only on the farmer s gross revenue however this design is not efficient if as is the case with available contracts the coverage function is based on imperfect estimators of individual yield and or price the producer s degree of prudence and the extent of basis risks have important influences on the optimal indemnity schedule in this broader context optimal protection is not provided by available u s crop insurance contracts and may include combinations of revenue insurance yield insurance futures and options contracts

jumps and stochastic volatility in oil prices time series evidence abstract in this paper we examine the empirical performance of affine jump diffusion models with stochastic volatility in a time series study of crude oil prices we compare four different models and estimate them using the markov chain monte carlo method the support for a stochastic volatility model including jumps in both prices and volatility is strong and the model clearly outperforms the others in terms of a superior fit to data our estimation method allows us to obtain a detailed study of oil prices during two periods of extreme market stress included in our sample the gulf war and the recent financial crisis we also address the economic significance of model choice in two option pricing applications the implied volatilities generated by the different estimated models are compared and we price a real option to develop an oil field our findings indicate that model choice can have a material effect on the option values

the conditional heteroscedasticity of the yen dollar exchange rate this paper examines the conditional heteroscedasticity of the yen dollar exchange rate a model is constructed by extending the asymmetric power autoregressive conditional heteroscedasticity model to a process that is fractionally integrated it is found that unlike the equity markets the appreciation and depreciation shocks of the yen against the dollar have similar effects on future volatilities although the results reject both the stable and the integrated models our analysis of the response coefficients of the past shocks and the application of the models to the estimation of the capital requirements for trading the currencies show that there are no substantial differences between the fractionally integrated models and the stable models 1998 john wiley sons ltd

volatility persistence in crude oil markets financial market participants and policy makers can benefit from a better understanding of how shocks can affect volatility over time this study assesses the impact of structural changes and outliers on volatility persistence of three crude oil markets brent west texas intermediate wti and organization of petroleum exporting countries opec between january 2 1985 and june 17 2011 we identify outliers using a new semi parametric test based on conditional heteroscedasticity models these large shocks can be associated with particular event patterns such as the invasion of kuwait by iraq the operation desert storm the operation desert fox and the global financial crisis as well as opec announcements on production reduction or us announcements on crude inventories we show that outliers can bias i the estimates of the parameters of the equation governing volatility dynamics ii the regularity and non negativity conditions of garch type models garch igarch figarch and hygarch and iii the detection of structural breaks in volatility and thus the estimation of the persistence of the volatility therefore taking into account the outliers on the volatility modelling process may improve the understanding of volatility in crude oil markets

market risk in commodity markets a var approach we put forward value at risk models relevant for commodity traders who have long and short trading positions in commodity markets in a 5 year out of sample study on aluminium copper nickel brent crude oil and wti crude oil daily cash prices and cocoa nearby futures contracts we assess the performance of the riskmetrics skewed student aparch and skewed student arch models while the skewed student aparch model performs best in all cases the skewed student arch model delivers good results and its estimation does not require non linear optimization procedures as such this new model could be relatively easily integrated in a spreadsheet like environment and used by market practitioners

jumps in financial markets a new nonparametric test and jump dynamics this paper introduces a new nonparametric test to detect jump arrival times and realized jump sizes in asset prices up to the intra day level we demonstrate that the likelihood of misclassiflcation of jumps becomes negligible when we use high frequency returns using our test we examine jump dynamics and their distributions in the u s equity markets the results show that individual stock jumps are associated with prescheduled earnings announcements and other company speciflc news events additionally s p 500 index jumps are associated with general market news announcements this suggests difierent pricing models for individual equity options versus index op

persistence in variance structural change and the garch model this article examines the persistence of the variance as measured by the generalized autoregressive conditional heteroskedasticity garch model in stock return data in particular we investigate the extent to which persistence in variance may be overstated because of the existence of and failure to take account of deterministic structural shifts in the model both an analysis of daily stock return data and a monte carlo simulation experiment confirm the hypothesis that garch measures of persistence in variance are sensitive to this type of model misspecification

oil prices and economic activity an asymmetric cointegration approach the aim of this paper is to study the long term relationship between oil prices and economic activity proxied by gdp to account for asymmetries existing in the links between the two variables we propose an approach based on asymmetric cointegration our empirical analysis concerns the u s economy but also the g7 europe and euro area economies results indicate that while standard cointegration is rejected there is evidence for asymmetric cointegration between oil prices and gdp

large shocks in the volatility of the dow jones industrial average index 1928 2013 we determine the events that cause large shocks in volatility of the djia index over the period 1928 2013 using a new semi parametric test based on conditional heteroscedasticity models we find that these large shocks can be associated with particular events financial crashes elections wars monetary policies etc we show that some shocks are not identified as extraordinary movements by the investors due to their occurring during high volatility episodes especially the 1929 1934 1937 1938 and 2007 2011 periods

modelling the relationship between future energy intraday volatility and trading volume with wavelet abstractalthough the energy and stock markets are both characterized by volatility and liquidity and there has been substantial research to explore the relationship between volatility and trading volume tv in stock markets few researchers have investigated this relationship in energy markets moreover studies that have explored this association within energy markets did not describe its nature or impetus to redress this oversight we investigate this relationship using intraday data from the oil and gas markets the most liquid energy markets in the world in this way the current article extends the previous studies through the use of a frequency approach to propose an original analysis of the relationship between volume and volatility more specifically we employ a continuous wavelet transform to identify the lead lag phase between volatility and volume this framework supplants usual time series modelling as it uses a measure of coherence for different frequencies and time scales to capture fu

structural breaks and garch models of exchange rate volatility we investigate the empirical relevance of structural breaks for garch models of exchange rate volatility using both in sample and out of sample tests we find significant evidence of structural breaks in the unconditional variance of seven of eight us dollar exchange rate return series over the 1980 2005 period implying unstable garch processes for these exchange rates and garch 1 1 parameter estimates often vary substantially across the subsamples defined by the structural breaks we also find that it almost always pays to allow for structural breaks when forecasting exchange rate return volatility in real time combining forecasts from different models that accommodate structural breaks in volatility in various ways appears to offer a reliable method for improving volatility forecast accuracy given the uncertainty surrounding the timing and size of the structural breaks copyright 2008 john wiley sons ltd

does oil move equity prices a global view many studies indicate that oil price shocks have an adverse effect on real output and hence an adverse effect on corporate profits where oil is used as a key input the present study examines whether and to what extent the adverse effect of oil price shocks impacts stock market returns to this end we analyse 35 datastream global industry indices for the period from april 1983 to september 2005 our findings indicate that oil price rises have a negative impact on equity returns for all sectors except mining and oil and gas industries generally these results are consistent with economic theory and evidence provided by previous empirical studies little evidence of any asymmetry is detected in the oil price sensitivities in light of our findings we recommend that international portfolio investors consider hedging oil price risk

outliers and garch models in financial data abstract we propose to extend the additive outlier ao identification procedure developed by franses and ghijsels franses p h ghijsels h 1999 additive outliers garch and forecasting volatility international journal of forecasting 15 1 9 to take into account the innovative outliers ios in a garch model we apply it to three daily stock market indexes and examine the effects of outliers on the diagnostics of normality

a century of research on agricultural markets this article provides a perspective on major innovations in research on agricultural markets over the past century we review research on market structure and performance vertical coordination arrangements and institutions for producer collective action contributions to empirical modeling of agricultural price determination and marketing margins are also evaluated as are innovations in research on spatial market relationships and the role of storage finally we discuss contributions to understanding market information systems and the functioning of market based mechanisms for agri

forecasting volatility of crude oil markets abstract this article investigates the efficacy of a volatility model for three crude oil markets brent dubai and west texas intermediate wti with regard to its ability to forecast and identify volatility stylized facts in particular volatility persistence or long memory in this context we assess persistence in the volatility of the three crude oil prices using conditional volatility models the cgarch and figarch models are better equipped to capture persistence than are the garch and igarch models the cgarch and figarch models also provide superior performance in out of sample volatility forecasts we conclude that the cgarch and figarch models are useful for modeling and forecasting persistence in the volatility of crude oil prices

forecasting the conditional volatility of oil spot and futures prices with structural breaks and long memory models this paper extends previous studies by investigating the relevance of structural breaks and long memory in modeling and forecasting the conditional volatility of oil spot and futures prices using a variety of garch type models our results can be summarized as follows first we provide evidence of parameter instability in five out of nine garch based conditional volatility processes for energy prices second long memory is effectively present in all the series considered and a figarch model seems to better fit the data but the degree of volatility persistence diminishes significantly after adjusting for structural breaks finally the out of sample analysis shows that volatility models accommodating instability and long memory characteristics of the data provide the best volatility forecasts for most cases

a nonparametric garch model of crude oil price return volatility the use of parametric garch models to characterise crude oil price volatility is widely observed in the empirical literature in this paper we consider an alternative approach involving nonparametric method to model and forecast oil price return volatility focusing on two crude oil markets brent and west texas intermediate wti we show that the out of sample volatility forecast of the nonparametric garch model yields superior performance relative to an extensive class of parametric garch models these results are supported by the use of robust loss functions and the hansen s 2005 superior predictive ability test the improvement in forecasting accuracy of oil price return volatility based on the nonparametric garch model suggests that this method offers an attractive and viable alternative to the commonly used parametric garch models

unique implementation of incentive contracts with many agents in this paper we consider the problem of implementation when a principal hires many agents and is not able to monitor their actions we distinguish two cases i when actions are mutually observable among agents ii when actions are not observable at all in i there is a mechanism in which the first best arises as a unique perfect equilibrium in ii we show by two examples that typically there are multiple equilibria if the principal merely offers a set of optimal sharing rules however we prove that the principal can use these optimal sharing rules as a starting point and construct a multi stage mechanism that has a unique second best perfect bayesian equilibrium

implementation in undominated nash equilibria without integer games a mechanism which uses neither integer games nor modulo games is shown to implement any social choice function in a production economy with private and excludable public goods more precisely th

modelling oil price volatility in this paper we examine the volatility of crude oil price using daily data for the period 1991 2006 our main innovation is that we examine volatility in various sub samples in order to judge the robustness of our results our main findings can be summarised as follows 1 across the various sub samples there is inconsistent evidence of asymmetry and persistence of shocks and 2 over the full sample period evidence suggests that shocks have permanent effects and asymmetric effects on volatility these findings imply that the behaviour of oil prices tends to change over short periods of time

estimating oil price value at risk using the historical simulation approach abstract in this paper we propose using value at risk var for oil price risk quantification var provides an estimation for the maximum oil price change associated with a likelihood level and can be used for designing risk management strategies we analyse three var calculation methods the historical simulation standard approach the historical simulation with arma forecasts hsaf approach developed in this paper and the variance covariance method based on autoregressive conditional heteroskedasticity models forecasts the results obtained indicate that hsaf methodology provides a flexible var quantification which fits the continuous oil price movements well and provides an efficient risk quantification

regime switching stochastic volatility evidence from the crude oil market this paper incorporates regime switching into the stochastic volatility sv framework in an attempt to explain the behavior of crude oil prices in order to forecast their volatility more specifically it models the volatility of oil return as a stochastic volatility process whose mean is subject to shifts in regime the shift is governed by a two state first order markov process the bayesian markov chain monte carlo method is used to estimate the models the main findings are first there is clear evidence of regime switching in the oil market ignoring it will lead to a false impression that the volatility is highly persistent and therefore highly predictable second incorporating regime switching into the sv framework significantly enhances the forecasting power of the sv model third the regime switching stochastic volatility model does a good job in capturing major events affecting the oil market

opec announcements and their effects on crude oil prices we investigate evidence on the effects of opec announcements on world oil prices by examining announcements from both official conferences and ministerial meetings on major international crudes including the key benchmarks and several other heavy and light grades with data from 1982 to 2008 we use event study methodology and find differentiation in the magnitude and significance of market responses to opec quota decisions under different price bands we also find some weak evidence of differentiation between light and heavy crude grades

are the crude oil markets becoming weakly efficient over time a test for time varying long range dependence in prices and volatility this paper analyzes the efficiency of crude oil markets brent and west texas intermediate by means of estimating the fractal structure of these time series we test for time varying degrees of long range dependence using the rescaled range hurst analysis and find evidence that this market has become more efficient over time these results are robust for controlling for short term autocorrelation by means of a shuffling procedure

implementation in undominated strategies a look at bounded mechanisms this paper examines the impact of placing natural restrictions on the mechanisms considered for implementation problems it is shown that if all mechanisms are considered and preferences satisfy a basic condition then any social choice correspondence can be implemented in undominated strategies an example points out that the strength of this result derives from the use of mechanisms with questionable features in part of the message space the agent who announces the highest integer is rewarded this sort of tail chasing construction common in the constructive proofs of the literature is used to assure that undesired strategy combinations do not form an equilibrium if such mechanisms are ruled out then the social choice correspondences which can be implemented in undominated strategies satisfy an incentive compatibility type condition called strategy resistence for social choice functions this is equivalent to strategy proofness this contrast suggests that this issue should be examined as it applies to other solution concepts used in implementation theory the last portion of the paper begins to explore the issue as it relates to nash implementation and undominated nash implementation

opec in the news abstract this paper introduces a newspaper article count index related to opec that rises in response to important opec meetings and events connected with opec production levels i use this index to measure how interest in opec varies over time and investigate how oil price volatility behaves when the index unexpectedly changes i find that unexpected increases in the newspaper index are strongly associated with higher levels of oil price volatility both realized and implied in some cases these unexpected movements appear to be driven by an unpredictable opec event such as the iraq invasion of kuwait in other cases such as the oil price collapses in late 2008 and late 2014 unforeseen developments in the oil market or broader economy seem to generate the unexpected movements in price volatility and interest in opec the newspaper index is highly correlated with google search volume data on opec an alternative measure of the amount of attention paid to opec events

oil and energy price volatility it is commonly believed that since the 1973 oil crisis oil and energy prices have been more volatile than other commodity prices this study examines monthly producer prices for thousands of products over the period january 1945 through august 2005 the results show that crude oil refined petroleum and natural gas prices are more volatile than prices for about 95 of products sold by domestic producers relative to crude commodities however crude oil prices are currently more volatile than about 65 of other products and oil price volatility first exceeded the median for crude commodities following the 1986 drop in oil prices

a simple forecasting mechanism for moral hazard settings abstract this paper studies a multiagent moral hazard setting we resolve the tacit collusion problem that arises in our setting while employing a solution concept that makes less demanding behavioral assumptions than nash a simple mechanism is constructed that approximately implements the second best solution in two rounds of iteratively removing strictly dominated strategies under our mechanism the agents best reply correspondences are well defined a small message space is employed and the messages can be interpreted as divisional forecasts journal of economic literature classification numbers c72 d82

structural vector autoregressions with nonnormal residuals in structural vector autoregressive svar modeling sometimes the identifying restrictions are insufficient for a unique specification of all shocks in this paper it is pointed out that specific distributional assumptions can help in identifying the structural shocks in particular a mixture of normal distributions is considered as a possible model that can be used in this context our model setup enables us to test restrictions which are just identifying in a standard svar framework the results are illustrated using a u s macro data set and a system of u s and european interest rates

a lagrange multiplier test for garch models abstract this paper extends the lagrange multiplier lm test to testing noise disturbances against garch disturbances in the linear regression model the resulting lm test for the garch alternative is identical to the lm test for an arch alternative

arch and bilinearity as competing models for nonlinear dependence in this article we consider whether the wide acceptance of autoregressive conditional heteroscedasticity arch models may be at the expense of other nonlinear processes such as bilinear models we first propose a joint test for arch and bilinearity a nonnested test is then suggested to determine whether nonlinear dependence should be attributed to arch or bilinearity the tests are then applied to three series when generalized arch garch models are taken as the null hypothesis we fail to reject it for all the data series when bilinearity is taken as the null however it is rejected in two cases moreover an out of sample forecasting exercise shows that the garch model is superior the results therefore indicate a strong preference for the garch model

non stationarities in financial time series the long range dependence and the igarch effects we give the theoretical basis of a possible explanation for two stylized facts observed in long log return series the long range dependence lrd in volatility and the integrated garch igarch both these effects can be explained theoretically if one assumes that the data are nonstationary

modelling oil price volatility with structural breaks in this paper we provide two main innovations i we analyze oil prices of two prominent markets namely west texas intermediate wti and brent using the two recently developed tests by narayan and popp 2010 and liu and narayan 2010 both of which allow for two structural breaks in the data series and ii the latter method is modified to include both symmetric and asymmetric volatility models we identify two structural breaks that occur in 1990 and 2008 which coincidentally correspond to the iraqi kuwait conflict and the global financial crisis respectively we find evidence of persistence and leverage effects in the oil price volatility while further extensions can be pursued the consideration of asymmetric effects as well as structural breaks should not be jettisoned when modelling oil price volatility

modeling and forecasting the volatility of carbon emission market the role of outliers time varying jumps and oil price risk abstract the objectives of this study are three fold first we aim to assess whether outliers or extreme observations occur in the european union allowance eua data second we examine if time varying jumps are present in the carbon emission market third we use the crude oil volatility index ovx to investigate the effect of oil market uncertainty on the emission price volatility in order to detect the possible outliers in the eua market we employ a standard methodology proposed by ane et al 2008 and identify several outliers in the emission data after spotting and then removing those extreme points we apply the garch jump models to both original and outlier free observations the results of the jump model show that while time varying jumps do exist in the uncorrected data most of the jump parameters however become insignificant in case of outlier free observations next the application of an extended egarch model in which ovx is introduced in the garch specification demonstrates that emission prices are highly sensitive to oil market implied volatility and that the impact of ovx on the eua market appears to be asymmetric additionally the use of forecast encompassing test documents that considering the outlier free data and using the information content of ovx would improve the volatility forecasts for the carbon emission market the results of our research carry important implications for both investors and policymakers

nash implementation and uncertain renegotiation we study nash implementation when the outcomes of the mechanism can be renegotiated among the agents but the planner does not know the renegotiation function that they will use we characterize the social objectives that can be implemented in nash equilibrium when the same mechanism must work for every admissible renegotiation function and show the importance of allowing the planner to sometimes take away resources from the agents

the efficiency of the crude oil markets evidence from variance ratio tests this study examines the random walk hypothesis for the crude oil markets using daily data over the period 1982 2008 the weak form efficient market hypothesis for two crude oil markets uk brent and us west texas intermediate is tested with non parametric variance ratio tests developed by wright j h 2000 alternative variance ratio tests using ranks and signs journal of business and economic statistics 18 1 9 and belaire franch j and contreras d 2004 ranks and signs based multiple variance ratio tests working paper department of economic analysis university of valencia as well as the wild bootstrap variance ratio tests suggested by kim j h 2006 wild bootstrapping variance ratio tests economics letters 92 38 43 we find that the brent crude oil market is weak form efficiency while the wti crude oil market seems to be inefficiency on the 1994 2008 sub period suggesting that the deregulation have not improved the efficiency on the wti crude oil market in the sense of making returns less predictable

large shocks small shocks and economic fluctuations outliers in macroeconomic time series summary we analyse fifteen post world war i1 us macroeconomic time series using a modified outlier identification procedure based on tsay 1988a large shocks appear to be present in all the series we examined furthermore there are three basic outlier patterns i outliers seem to be associated with business cycles 2 outliers are clustered together both over time and across series 3 there appears to be a dichotomy between outlier behaviour of real versus nominal series also after controlling for outliers much of the evidence of non linearity in many of the time series is eliminated

finding optimal price risk management instruments the case of the spanish potato sector this article offers a comprehensive analysis of the problem of choosing between alternative market risk management instruments we model farmers behavior to optimize the certainty equivalent formulated by a mean variance model by combining instruments with and without basis risk results are expressed as the demands for hedging with futures forward contracts and insurance theoretical results are applied to a selection of spanish producers of fresh potatoes a sector that is exposed to significant market risks amsterdam s euronext provides potato futures prices and the recently launched revenue insurance in spain provides the example for price insurance three conclusions summarize the article s main findings first we show that spanish potato revenue insurance subsidies are a factor that determines the instrument rankings and choice second the efficiency of insurance subsidies is generally low finally the amsterdam potato futures market does not provide a cost effective means to manage price risks for spanish fresh potato growers

a markov switching model of the conditional volatility of crude oil futures prices abstract this paper examines the temporal behaviour of volatility of daily returns on crude oil futures using a generalised regime switching model that allows for abrupt changes in mean and variance garch dynamics basis driven time varying transition probabilities and conditional leptokurtosis this flexible model enables us to capture many complex features of conditional volatility within a relatively parsimonious set up we show that regime shifts are clearly present in the data and dominate garch effects within the high volatility state a negative basis is more likely to increase regime persistence than a positive basis a finding which is consistent with previous empirical research on the theory of storage e g fama and french 1988a fama and french 1988b and ng and pirrong 1994 the volatility regimes identified by our model correlate well with major events affecting supply and demand for oil out of sample tests indicate that the regime switching model performs noticeably better than non switching models regardless of evaluation criteria we conclude that regime switching models provide a useful framework for the financial historian interested in studying factors behind the evolution of volatility and to oil futures traders interested short term volatility forecasts

output growth and its volatility the gold standard through the great moderation this study examines the relationship between u s output growth and its volatility over the period 1876 i to 2012 ii we adjust the data for outliers and structural breaks we employ generalized autoregressive conditional heteroskedasticity garch and exponential garch egarch specifications normality and homoskedasticity appear only in the garch or egarch model that corrects for the outliers when including the break in the mean equation high volatility persistence remains after also accommodating the breaks in the variance equation the integrated garch effect proves spurious either for the symmetric or the asymmetric model finally our empirical results suggest that the finding of higher output growth volatility stimulating output growth and higher output growth reducing its volatility obtained from the symmetric garch in mean garch m model also proves spurious as a result of the emergence of an asymmetric effect our more appropriately specified asymmetric egarch m model suggests positive volatility in mean and level effects in the long period real gross national product series

oil prices stock markets and portfolio investment evidence from sector analysis in europe over the last decade this article extends the understanding of oil stock market relationships over the last turbulent decade unlike previous empirical investigations which have largely focused on broad based market indices national and or regional indices we examine short term linkages in the aggregate as well as sector by sector levels in europe using different econometric techniques our main findings suggest that the reactions of stock returns to oil price changes differ greatly depending on the activity sector in the out of sample analysis we show that introducing oil asset into a diversified portfolio of stocks allows to significantly improve its risk return characteristics

a response to glazer and rosenthal we are most grateful to glazer and rosenthal for the attention they have paid to our work abreu and matsushima 1992a b c in the process of criticizing our mechanism they have provided an elegant exposition of it which usefully supplements our own efforts the criticisms themselves we feel are misplaced and based on a close reading but narrow interpretation of our results glazer and rosenthal seek to show that in our mechanisms the iterative removal of strictly dominated strategies is or indeed ought to be controversial in terms of conventional decision theory the iterative logic is impeccable when iterative deletion leads to a unique profile that profile is the unique rationalizable profile the unique nash equilibrium and so on of course the logic of iterative dominance entails common knowledge of rationality the theoretical coherence of this assumption has been questioned in the context of backward programming in extensive form games see luce and raiffa 1957 pp 80 81 rosenthal 1981 basu 1988 reny 1992a 1992b bonanno 1991 binmore 1987a 1987b and gul 1989 among others these paradoxes of common knowledge of rationality have been highlighted in stylized examples such as the finitely repeated prisoners dilemma and rosenthal s centipede game which in fact has been a seminal inspiration for this recent literature 2 but our mechanisms are simultaneous there is no opportunity to demonstrate irrationality strategic or otherwise and therefore no scope to rationalize iteratively dominated behavior from a decision theory perspective the glazer and rosenthal critique might therefore be viewed as an elaborate revival of the indefensible claim that players in a one short prisoners dilemma will choose not to confess because they are both better off doing so than by both playing their dominant strategies within the standard game theory paradigm there is really nothing more to be said before turning to issues of bounded rationality we note that the glazer and rosenthal critique is essentially premised on the existence of a countervailing focal point but what is a focal point the notion is notoriously vague and we are aware of no widely accepted definition 3 this is not to deny that in very simple and particular games certain behavior may be focal frequently focalness is identified with a pareto dominating equilibrium and this is the point of view glazer and rosenthal seem to adopt 4 this is implicit in their acknowledgement that when the social choice function does satisfy pareto optimality our objection loses much of its immediate

correlation and relative performance evaluation this paper reexamines the issue of relative versus joint incentive schemes in a multi agent moral hazard framework the model allows a full analysis of the information and dependence structure an important result is that the widespread notion that greater correlation in outcomes calls for more competition is not robust first when the dependence structure is effort sensitive the optimal incentive scheme in general mixes elements of relative evaluation and joint evaluation second under limited liability higher equilibrium correlation tends to make joint performance evaluation more desirable examples are provided regarding incentives in firms finance and innovation

the persistence of volatility and stock market fluctuations this paper examines the potential influence of changing volatility in stock market prices on the level of stock market prices it demonstrates that volatility is only weakly serially correlated implying that shocks to volatility do not persist these shocks can therefore have only a small impact on stockmarket prices since changes in volatility affect expected required rates of return for relatively short intervals these findings lead us to be skeptical of recent claims that the stock market s poor performance during the 1970 s can be explained by volatility induced increases in risk premia this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item this abstract was borrowed from another version of this item

testing for arch in the presence of additive outliers in this paper we investigate the properties of the lagrange multiplier lm test for autoregressive conditional heteroskedasticity arch and generalized arch garch in the presence of additive outliers ao s we show analytically that both the asymptotic size and power are adversely affected if ao s are neglected the test rejects the null hypothesis of homoskedasticity too often when it is in fact true while the test has difficulty detecting genuine garch effects several monte carlo experiments show that these phenomena occur in small samples as well we design and implement a robust test which has better size and power properties than the conventional test in the presence of ao s applications to the french industrial production series and weekly returns of the spanish peseta us dollar exchange rate reveal that sometimes apparent garch effects may be due to only a small number of outliers and conversely that genuine garch effects can be masked by outliers

which determinant is the most informative in forecasting crude oil market volatility fundamental speculation or uncertainty abstract this paper aims to identify the most informative determinant in forecasting crude oil market volatility we use a new garch class model based on mixed data sampling regression and the dynamic model averaging combination method to examine the predicting power of the determinants we integrate both the global economic policy uncertainty gepu indices and several national economic policy uncertainty epu indices with traditional determinants such as global oil demand supply and speculation our analysis suggests that the epu indices comprehensively integrate the information contained in other determinants specifically gepu indices and the u s s epu index have superior predictive powers for west texas intermediate spot oil volatility this finding highlights the importance of epu indices implying that they are key factors to consider when determining crude oil market volatility

effects of oil price fall on the betas in the unconventional oil gas industry abstract we examine the consequences of the oil prices movements started in july 2014 on the financial systematic risk proxied by betas of firms operating in the unconventional oil gas industry compared to that of the conventional oil gas players the analysis is developed using two cross section regressions performed before and after the 2014 oil price drop respectively the results look coherent with the reasonable belief that a sharp and sudden decrease in the oil price can generally lead to higher betas in the oil gas industry interestingly it emerged that the market tends to attribute an additional risk to unconventional firms and analyzing the regression coefficients evolution it appears that this circumstance has been substantially amplified by the 2014 oil price shock to our knowledge this is the first paper covering the topic treated

optimal incentive schemes with many agents the grossman hart principal agent model of moral hazard is extended to the multiple agent case to explore the use of relative performance in optimal incentive contracting under the assumption that the principal chooses incentive schemes to implement agent actions as nash equilibria necessary and sufficient conditions are derived for the optimality of independent contracts of rank order tournaments and for attainability of the first best in this context the relation of the principal s welfare to the correlation between the underlying randomness in outputs of different agents is also investigated finally some problems with the nash equilibrium implementation assumption are discussed in this paper we extend the grossman hart analysis of the principal agent problem to a multiple agent setting in this version of the problem a risk neutral principal is assumed to observe the output or a performance index for each risk averse agent the output of any agent depends on a privately observable action chosen by the agent and an exogenous random variable the realization of which is not observed either by the principal or by the agent before choosing its action we especially focus attention on the role of relative performance evaluation in optimal incentive contracts and the way this depends on properties of the underlying production technology and the joint distribution of the random variables affecting the outputs of different agents in section 2 of the paper we consider the principal s problem of finding an optimal incentive scheme and an action tuple for agents subject to the constraint that the latter be implemented as a nash equilibrium between agents by the chosen incentive scheme where agents must attain at least their reservation utilities a characterization of optimal incentive schemes is derived analogous to the grossman hart characterization for the single agent problem this characterization is then utilized to find sufficient and generically necessary conditions for a optimal contracts for any agent to be independent of the performance of other agents and b optimality of rank order tournaments where payments depend solely on ordinal comparisons of output across agents we then describe a necessary and sufficient condition for the principal to extract maximum advantage from relative performance clauses i e achieve the first best level of expected utility in the multiagent situation an implication of this result is that under fairly weak conditions perfect correlation in the underlying production uncertainties for different agents enables the principal to attain the first best if and only if sufficiently heavy penalties can be inflicted on agents we then enquire what happens in intermediate cases of non perfect correlation it turns out that while in general the principal s welfare is a continuous function of the correlation coefficient it is not always nondecreasing in the latter because the correlation coefficient is not a general measure of association between two random variables but rather a measure of linear association between them

stopping agents from cheating abstract when a principal hires two or more agents to work in a correlated environment each agent s reward will depend on the other s performance unfortunately with just the usual optimal incentive constrained contracts being offered the agents strictly prefer to play equilibrium strategies other than those desired by the principal they cheat however the principal can use a more subtle contractual mechanism to stop them from cheating at no extra cost this mechanism uses one agent to police the other and exploits certain properties of the optimal contracts

detecting multiple breaks in financial market volatility dynamics the paper evaluates the performance of several recently proposed tests for structural breaks in the conditional variance dynamics of asset returns the tests apply to the class of arch and sv type processes as well as data driven volatility estimators using high frequency data in addition to testing for the presence of breaks the statistics identify the number and location of multiple breaks we study the size and power of the new tests for detecting breaks in the conditional variance under various realistic univariate heteroscedastic models change point hypotheses and sampling schemes the paper concludes with an empirical analysis using data from the stock and fx markets for which we find multiple breaks associated with the asian and russian financial crises these events resulted in changes in the dynamics of volatility of asset returns in the samples prior and post the breaks copyright 2002 john wiley sons ltd

structural change and estimated persistence in the garch 1 1 model abstract the estimated persistence parameter in the garch 1 1 model is biased upwards when the parameters of the model are not constant throughout the sample the present paper explains the mechanics of this behavior for a particular class of estimates

hedging multiple price uncertainty in international grain trade commodity and freight futures contracts are analyzed for their effectiveness in reducing uncertainty for international traders a theoretical model is developed for a trader exposed to several types of risk ols hedge ratio estimation is compared to the sur and the multivariate garch methodologies explicit modeling of the time variation in hedge ratios via the multivariate garch methodology using all derivatives and taking into account dependencies between prices results in reductions in risk even after accounting for transaction costs results confirm that while the commodity futures contracts are important for hedging risk freight futures are a useful mechanism for reducing risk copyright 2000 oxford university press

determination of the recommended hedging ratio the traditional literature on commodity futures markets defined a hedge as a futures market position which is equal but opposite to the individual s cash market position more recent studies have recognized that the futures market position need not equal the cash market position to constitute a hedge many researchers have theoretically solved for the optimal futures and cash market positions for example heifner johnson ward and fletcher and telser determined the optimal futures and cash market positions simultaneously peck determined the optimal futures market position assuming that the cash market position was given the formulas for the optimal futures and cash holdings differ from study to study because of the different underlying assumptions however general implications can be deduced from these studies concerning the size of the optimal hedging ratio i e the ratio of the optimal futures position to the optimal cash position in this paper it is argued that the optimal hedging ratios consistent with the results obtained by johnson ward and fletcher and telser are identical to the optimal hedging ratio derived byheifner 1972 1973 the exercise provides a major implication for hedging strategy which is consistent with all of these studies that the optimal hedging ratio is independent of the individual s risk aversion even though the optimal positions are themselves not independent of the risk parameter this implication is also valid for the minimum risk hedging ratio derived by johnson ederington and mckinnon finally the optimal hedging ratio in peck remains dependent on the risk parameter because the cash market position is assumed to be given

bounded influence estimator for garch models evidence from foreign exchange rates previous research indicates that the maximum likelihood estimates of generalized autoregressive conditional heteroscedasticity garch models on foreign exchange rates under various distributional assumptions are sensitive to the presence of outliers the advantage of the proposed bounded influence estimator bie is that it limits the influence of a small subset of data and is asymptotically normal the bie provides more consistent and robust estimates than maximum likelihood estimator mle and semi parametric estimator both of which tend to underestimate volatility persistence due to outliers it is thus robust to outliers and model misspecification results of bie estimates of garch models on the exchange rate series of five major currencies indicate that bie offers an efficient mechanism for down weighting outlying observations and is a competitive alternative to mle

oil price dynamics 2002 2006 abstract oil price dynamics during 2002 2006 have been characterized by high volatility high intensity jumps and strong upward drift and were concomitant with underlying fundamentals of oil markets and world economy namely pressure on oil prices resulting from rigid crude oil supply and expanding world demand for crude oil a change in the oil price process parameters would require a change in underlying fundamentals market expectations extracted from call and put option prices anticipated no change in underlying fundamentals in the short term markets expected oil prices to remain volatile and jumpy and with higher probabilities to rise rather than fall above the expected mean

oil shock and economic growth in japan a nonlinear approach abstract this paper investigates the relationship between oil price shock and economic growth on the basis of the nonlinear approach developed by hamilton hamilton j 2001 a parametric approach to flexible nonlinear inference econometrica 537 573 we use the approach also in hamilton hamilton j 2003 what is an oil shock journal of econometrics 363 398 of capturing this relationship in japan in a nonlinear model the idea is that negative oil price shocks price increase tend to have larger impact on growth than positive shocks do our empirical evidence confirmed the existence of nonlinearity between these two variables and a flexible nonlinear model is estimated additionally several other form of nonlinearity are estimated and tested

volatility in crude oil futures a comparison of the predictive ability of garch and implied volatility models the wti future contract quoted at the nymex is the most actively traded instrument in the energy sector this paper compares the predictive ability of two approaches which can be used to forecast volatility garch type models where forecasts are obtained after estimating time series models and an implied volatility model where forecasts are obtained by inverting one of the models used to price options although the main scope of the research discussed here is to evaluate which model produces the best forecast of volatility for the wti future contract evaluated according to statistical and regression based criteria we also investigate whether volatility of the oil futures are affected by asymmetric effects whether parameters of the garch models are influenced by the distribution of the errors and whether allowing for a time varying long run mean in the volatility produces any improvement on the forecast obtained from garch models

modeling and forecasting crude oil markets using arch type models this study investigates the time varying volatility of two major crude oil markets the west texas intermediate wti and europe brent a flexible autoregressive conditional heteroskedasticity arch model is used to take into account the stylized volatility facts such as clustering volatility asymmetric news impact and long memory volatility among others the empirical results indicate that the intensity of long persistence volatility in the wti is greater than in the brent it is also found that for the wti the appreciation and depreciation shocks of the wti have similar impact on the resulting volatility however a leverage effect is found in brent although both the estimation and diagnostic evaluations are in favor of an asymmetric long memory arch model only the wti models provide superior in the out of sample forecasts on the other hand from the empirical out of sample forecasts it appears that the simplest parsimonious generalized arch provides the best forecasted evaluations for the brent crude oil data

jump dynamics with structural breaks for crude oil prices this study investigates the joint phenomena of permanent and transitory components in conditional variance and jump intensity along with verification of structural breaks for crude oil prices we adopt a component arji model with structural break analysis utilizing daily data on west texas intermediate crude oil spot and futures contracts the analytical results verify the existence of permanent and transitory components in conditional variance with the permanent component of conditional variance increasing with the occurrence of a sudden major event such as the iraqi invasion of kuwait operation desert storm and the war between the us and iraq and a relatively greater increase in the transitory component over the same period notably jump intensity fluctuates with an increase in the transitory component of conditional variance in response to abnormal events it is the transitory component which serves as the primary influential factor for jumps in returns therefore speculators are willing to take large risks particularly with respect to anticipating future price movements or gambling in the hopes of rapidly making substantial gains thus speculators prefer the temporary volatility component and engage in trade activities however investors prefer the permanent volatility component because they may well be better off relocating their assets into more stable portfolios to outperform the market portfolio over the long run

hedging strategy for crude oil trading and the factors influencing hedging effectiveness abstract this study analyzes the hedging effectiveness of different hedge type and period by korean oil traders both crude oil price and exchange rate risks are considered theoretical models are formulated to estimate the hedge ratios by separate and complex hedge types the hedging period covers 1 12 months this study also performs some statistical works to investigate the relationship between the hedging effectiveness and the crude oil price sensitivity to exchange rate in addition the relationship between the hedging effectiveness and the volatilities of crude oil price and exchange rate is analyzed

budgetary and producer welfare effects of revenue insurance legislation passed in 1996 changed the way the u s federal government acts to reduce risks faced by u s crop products the authors compare the new alternative forms of revenue insurance to the 1990 deficiency payment program and to a no program alternative they estimate the effects of the alternative polices on the acreage allocations of a representative farm on the expected government cost and on producer welfare simulation results indicate that a revenue insurance scheme that guarantees 75 percent of expected revenue to risk averse produced could provide approximately the same level of benefits as the 1990 program at as little as one fourth the cost

forecasting crude oil market volatility further evidence using garch class models abstract this paper extends the work of kang et al 2009 we use a greater number of linear and nonlinear generalized autoregressive conditional heteroskedasticity garch class models to capture the volatility features of two crude oil markets brent and west texas intermediate wti the one five and twenty day out of sample volatility forecasts of the garch class models are evaluated using the superior predictive ability test and with more loss functions unlike kang et al 2009 we find that no model can outperform all of the other models for either the brent or the wti market across different loss functions however in general the nonlinear garch class models which are capable of capturing long memory and or asymmetric volatility exhibit greater forecasting accuracy than the linear ones especially in volatility forecasting over longer time horizons such as five or twenty days

optimal incentive contracts with multiple agents abstract a setting in which a single principal contracts with two agents who possess perfect private information about their own productivity is considered with correlated productivities each agent s private information also provides a signal about the other agent s productivity in contrast to the setting in which there is only one agent it is shown that such private information may be of no value to the agents it is only if the agents are risk averse that their private information may allow them to command rents moreover when the agents are constrained only to reveal their private information truthfully as a nash equilibrium the pareto optimal incentive scheme may induce the agents to adopt strategies other than truth telling this leads to the consideration of truth telling equilibria that are not pareto dominated in the subgame played by the agents among all such equilibria the one preferred by the principal restricts one agent to tell the truth as a dominant strategy and the other as a nash response to truth

futures hedging under price basis and production risk we consider the hedging problem of a firm that has three sources of risk price basis and yield uncertainty an exact solution for the optimal futures hedge is derived under the assumption that the three random variables are jointly normally distributed and that utility is of the cara type unlike the mean variance approximation applied in previous research we show that the optimal hedge does depend on risk attitudes even when the agent perceives the futures price as being unbiased the theoretical results are applied empirically to the problem of hedging soybean production in iowa the exact solution relying on cara and normality is compared with numerical solutions under lognormal distributions and crra utility

forecasting crude oil market volatility further evidence with jumps this paper analyzes volatility models and their forecasting abilities in the presence of jumps in two crude oil markets brent and west texas intermediate wti between january 6th 1992 and december 31st 2014 we compare a number of garch type models that capture short memory as well as asymmetry garch gjr garch and egarch estimated on raw returns to three competing approaches that deal with the presence of jumps garch type models estimated on jump filtered returns and two new classes of volatility models called generalized autoregressive score gas and markov switching multifractal msm models estimated using raw returns the forecasting performance of these volatility models is evaluated using the model confidence set approach which allows us to identify a subset of models that outperform all the other competing models we find that asymmetric models estimated on filtered returns provide better out of sample forecasts than do garch gas type and msm models estimated on raw return series for brent and wti returns

an analysis of the principal agent problem most analyses of the principal agent problem assume that the principal chooses an incentive scheme to maximize expected utility subject to the agent s utility being at a stationary point an important paper of mirrlees has shown that this approach is generally invalid we present an alternative procedure if the agent s preferences over income lotteries are independent of action we show that the optimal way of implementing an action by the agent can be found by solving a convex programming problem we use this to characterize the optimal incentive scheme and to analyze the determinants of the seriousness of an incentive problem