中国农产品期货市场效率实证分析:1998-2002

本文旨在检验1998-2002年我国小麦和大豆期货市场效率并对农产品期货市场和现货市场做出相应评估.通过采纳Johansen协整检验方法,论文针对三种不同的现货价格以及预测跨度从1周到6个月不等的期货价格进行了正式统计检验.结果表明,我国大豆期货价格与现货价格之间存在长期均衡关系,大豆期货市场的短期效率相对较高.小麦期货市场缺乏效率,这可能应当归因于期货市场发展尚不成熟以及投机过度.     

Cointegration and detectable linear and nonlinear causality: analysis using the London Metal Exchange lead contract

This study applies linear and nonlinear Granger causality tests to examine the dynamic relation between London Metal Exchange (LME) cash prices and three possible predictors. The analysis uses matched quarterly inventory, UK Treasury bill interest rates, futures prices and cash prices for the commodity lead traded on the LME. The effects of cointegration on both linear and nonlinear Granger causality tests is also examined. When cointegration is not modelled, evidence is found of both linear and nonlinear causality between cash prices and analysed predictor variables. However, after controlling for cointegration, evidence of significant nonlinear causality is no longer found. These results contribute to the empirical literature on commodity price forecasting by highlighting the relationship between cointegration and detectable linear and nonlinear causality. The importance of interest rate and inventory as well as futures price in forecasting cash prices is also illustrated. Failure to detect significant nonlinearity after controlling for cointegration may also go some way to explaining the reason for the disappointing forecasting performances of many nonlinear models in the general finance literature. It may be that the variables are correct, but the functional form is overly complex and a standard VAR or VECM may often apply.     

制造业企业套期保值方案实施的绩效评价研究

套期保值是现代企业规避商品价格剧烈波动的最理想的风险管理工具之一,通过套期保值,可以改变企业在原材料采购过程中的被动性,使企业主动控制生产成本,保证经营利润。对企业开展的套期保值业务进行正确的绩效评价,对提高企业开展套期保值业务的积极性具有重要的指导意义。通过对影响企业套期保值效果因素的分析,提出企业可以将期货和现货市场的综合收益以及期货市场套保品种的均价作为评价套期保值绩效的参考对象,能够正确引导企业合理参与套期保值,正确评价套期保值效果。     

Optimal gasoline hedging strategies using futures contracts and exchange-traded funds

This article employs a variety of econometric models (including OLS, VEC/VAR, DCC GARCH and a class of copula-based GARCH models) to estimate optimal hedge ratios for gasoline spot prices using gasoline exchange-traded funds (ETFs) and gasoline futures contracts. We then compare their performance using four different measures from the perspective of both their hedging objectives and trading position using four different measures: variance reduction measure, utility-based measure and two tail-based measures (value at risk and expected shortfall). The impact of the 2008 financial market crisis on hedging performance is also investigated. Our findings indicate that, in terms of variance reduction, the static models (OLS and VEC/VAR) are found to be the best hedging strategies. However, more sophisticated time-varying hedging strategies could outperform the static hedging models when the other measures are used. In addition, ETF hedging is a more effective hedging strategy than futures hedging during the high-volatility (crisis) period, but this is not always the case during the normal time (post-crisis) period.     

Financial frictions and the futures pricing puzzle

In perfect capital markets, the futures price of an asset should be an unbiased forecast of its realized spot price when the contract matures. In reality, futures prices are often higher for some assets and lower for others. However, there is no stability in the relationship between futures prices and the realized spot prices. This instability has been a puzzle in the existing financial literature. The key to this puzzle may lie in the nature of the model and the lack of market imperfections. In this study, we take a theoretical approach in a dynamic multi-period environment. We incorporate competition between disparate economic agents and impose financial frictions (i.e., imperfections) that are in the form of hedging and borrowing limits on them. Our model gives rise to multiple equilibria, each with unique market clearing prices, with the market switching between these equilibria. Our analysis incorporates a comprehensive consideration of the risks faced by the futures markets participants (i.e., speculators and hedgers) and leads to a better understanding of the puzzle.     

Can investors of Chinese energy stocks benefit from diversification into commodity futures?

We attempt to evaluate the diversification potential of commodity futures for energy stocks in China. With a variety of copula functions and three risk-based dynamic measures, our results show that even though commodity futures are not helpful in improving the risk-adjusted returns of energy stocks, they can significantly reduce the volatilities and expected-shortfalls of the diversified portfolios. Such diversification benefits are much larger during large market downturns than during normal times. In particular, gold (copper) futures are the most (least) attractive in diversifying risks of energy stocks in most cases. The results also highlight that the non-linear dependence cannot be ignored when estimating the diversification benefits, and more various risk hedging strategies are expected for investors holding energy stocks, especially coal company stocks.     

Futures markets and commodity options: Hedging and optimality in incomplete markets

This paper examines the allocational roles of futures markets and commodity options in multi-good and multi-period economies. In a continuous-time model with time-additive utilities and homogeneous beliefs, trading in “unconditional” futures contracts, the market portfolio and a riskless asset gives any Pareto-optimal allocation. Individuals' optimal holdings of futures contracts in the continuous-time model are related to their consumption bundles and to their risk tolerances. It is shown that both hedging and “reverse hedging” behavior are possible. In the general model with discrete trading, options on portfolios of commodity options are shown to permit any unconstrained Pareto-optimal allocation.     

中国棉花期货和现货市场的价格关系研究

期货市场和现货市场之间的价格发现功能一直是监管部门和投资者十分关心的问题。本文借助信息共享模型、脉冲响应函数和方差分解等方法,对中国棉花的期、现货市场间的价格关系进行实证研究,定量刻划了期、现货市场在价格发现中的作用。研究结果表明:棉花期、现货价格之间存在显著的双向引导关系;二者存在长期均衡关系;期、现货市场都扮演重要的价格发现角色,期货市场在价格发现中处于主导地位。     

Measuring the impacts of cash settlement: A stochastic volatility approach

Prior to 1986, any opening position on feeder cattle futures contract must be settled with physical delivery after the last trading day. Due to dwindling commercial interests, Chicago Mercantile Exchange (CME) subsequently replaced the system with the cash settlement method. It was argued that cash settlement would help improve the convergence between cash and futures prices and reduce the basis variability. In this paper, we adopted stochastic volatility (SV) models to investigate this conjecture. The models allow for time-varying volatility. We found strong evidence of reduction in basis and in basis variance after cash settlement. Moreover, cash settlement induced a change in the structural relationship between cash and futures prices. The futures market has become more efficient after the change in settlement methods.     

Strategic use of futures and options by commodity processors

The impacts of input–output price relationships on end-users' demands for positions in futures and options are analyzed using a mean-variance portfolio model and applied to price risk management in the bread manufacturing industry. A production relationship was assumed between the input and resultant output, and correlation between the input and output prices were introduced into the portfolio model. The optimal hedge ratio can be either positive or negative depending upon the relationship between the input and output price standard deviation adjusted for production technology and input–output price correlation. Introduction of a call option into the portfolio (in addition to the futures) does not change the hedging demand for futures; however, the speculative component changes. The results show that the addition of input–output linear production and price correlation relationships would not justify a hedging role for options unless there is bias in the futures and/or options markets.     

HEDGING,SPECULATION, AND INVESTMENT IN BALANCE‐SHEET TRIGGERED CURRENCY CRISES*

This paper explores the linkage between corporate risk management strategies, investment, and economic stability in an open economy with a flexible exchange rate regime. Firms use currency futures contracts to manage their exchange rate exposure – caused by balance sheet effects as in Krugman (2000) – and therefore their investments’ sensitivity to currency risk. We find that, depending on whether futures contracts are used for risk reduction (i.e. hedging) or risk taking (i.e. speculation), the implied magnitudes of recessions and booms are decreased or increased. Corporate risk management can therefore substantially affect economic stability on the macrolevel.     

我国引入股指期货交易的意义及可行性分析

到目前为止,我国股市仅有现货交易,却没有有效的风险回避机制,这必将影响到我国股市健康发展。因此,当前开发我国股指期货交易可以回避股市系统风险,增加市场流动性,促进股价合理波动,从而增强证券市场的竞争力。同时,在我国已经形成了较为完善的交易和监管体系,并拥有了相当规模的投资群体,开办股指期货的市场条件已具备。     

On the comparison of Schwartz and Smith’s two- and three-factor models on commodity prices

Since Schwartz and Smith (2000) published their study on two-factor model on commodity prices, many studies have used this model and others have extended it. The authors also proposed the three-factor model due to the poor fitting of the two-factor one on long-term futures prices. At that time the authors had only long-term prices from a private source to calibrate, test and compare these models. No public data on long-term future contracts were available. On the other hand, during the last decade the commodity prices soared as did the liquidity of long-term contracts. This means that the interest of the agents in the management of their risk on long-term positions increased the same way and this is the motivation for this study. In this article, we revisit the comparison between two- and three-factor models using public data for short- and long-term contracts (we use up to the 67-month-ahead contract). We also provide a detailed derivation of the three-factor model differently from that of the original article. Following the original article of Schwartz and Smith, we used oil futures prices traded on the New York Mercantile Exchange to calibrate the model. The results show a better fit of the three-factor model for the term structure of prices and volatilities mainly for long maturities contracts, while the two-factor model in most portions of the curve underestimates the risk premiums. This type of analysis is important not only for daily agents negotiating the physical commodities through long-term contracts but also for investment decisions on development of real projects.     

Comparison of Some Static Hedging Models of Agricultural Commodities Price Uncertainty

In static framework, many hedging strategies can be settled following the various hedge ratios that have been developed in the literature. However, it is difficult to choose among them the best the appropriate strategy according the to preference or economic behavior of the decision-maker such as prudence and temperance. This is so even with the hedging effectiveness measure. After introducing a hedging ratio that take into account the prudence and temperance of the decision maker, we propose a ranking based approach to measure the effectiveness using L-moment to classify hedge portfolios, hence hedge ratios, with regard to their performance. Moreover, we deal with the hedging issue in presence of quantity and rollover risks and derive an optimal strategy that depends upon the basis and insurance contract. Such hedging issue includes the relevant risks encountered in practice and we relate how insurance contract, specially designed for production risk could affect the futures hedge. The application on some agricultural futures prices data at hands shows that taking into account quantity and rollover risks leads to better hedging strategy based on the L-performance effectiveness measure.

     

Cointegration and price discovery in US corn cash and futures markets

Using prices from 182 cash markets from seven states and the Chicago Board of Trade futures, we investigate cointegration and price discovery for corn. Analysis based on cash–futures pairs reveals that cointegration holds for 52 cash markets and failures tend to happen farther away from futures delivery locations. Cash generally are as important as futures prices as information sources in the long run and cash to futures information flow is most likely in the short run. Contributions to price discovery also are measured quantitatively for cointegrated cases. Analysis based on state-level cash prices indicates bidirectional information flow between cash and futures prices under a bivariate model, and futures to cash information flow under the octavariate model with all cash and the futures series. Comparisons of the two models show that including local cash markets in a price relationship model highlights cointegration and the futures’ price discovery role and could benefit cash price forecasting. Finally, evidence of nonlinear causality is found.     

NEGATIVE CORRELATION BETWEEN STOCK AND FUTURES RETURNS: AN UNEXPLOITED HEDGING OPPORTUNITY?

The negative correlation between equity and commodity futures returns is widely perceived by investors as an unexploited hedging opportunity. A Lucas (1982) asset‐pricing model is adapted to analyse the fundamentals driving equity and commodity futures returns. Using the model we argue that such a negative correlation could arise as an equilibrium relationship which reflects traders' perceptions about the shocks driving the fundamentals such as energy and consumables, and does not necessarily indicate any hedging opportunity.     

Does economic policy uncertainty matter for commodity market in China? Evidence from quantile regression

ABSTRACT

This paper investigates the effect of economic policy uncertainty (EPU) on China’s agricultural and metal commodity futures returns across quantiles. We address this issue using the panel quantile regression approach, which allows for a more complete analysis of various conditions in the commodity market (i.e. bearish, normal, and bullish markets). Our empirical results reveal that domestic EPU shocks have a significantly negative effect on agricultural futures returns in bearish markets and a significantly positive effect on metal futures returns in bullish markets. The impacts of both domestic and U.S. EPU shocks on commodity markets are heterogeneous across quantiles and are sector specific. Additionally, by isolating positive and negative EPU shocks, the regression and test results indicate an asymmetric response of commodity futures prices in bullish markets. Moreover, our findings indicate that the metal futures market has a higher financialisation level than the agricultural futures market. The findings can be utilized by policymakers and investors.     

Testing commodity futures market efficiency under time-varying risk premiums and heteroscedastic prices

We propose a novel test to measure market efficiency while estimating the time-varying risk premiums of commodity futures, given that the prices are heteroscedastic. The risk premium is estimated using a state-space model with a Kalman filter modified for heteroscedasticity. Using 79 commodity futures traded on 16 exchanges during the period 2000–2014 and a Monte Carlo simulation, we demonstrate that the proposal produces robust results compared with conventional approaches. The global financial crisis has improved the efficiency and affected the trading volumes of commodity futures, but it has had no effect on the average or the volatility of risk premiums.     

Environmental rights on the futures markets an application to the dutch manure market

A study was carried out to analyze futures markets for tradable rights after a cash market was initiated. Furthermore, some indication was given on the size of such a futures market to provide insight into its viability. Futures markets can play a role in solving environmental problems, by making the market for pollution rights (i.e. P₂O₅ rights) and agro rights (milk rights, sugar rights and P₂O₅ rights) more effective and transparent. Moreover, the market for tradable rights would be able to meet the users' need for hedging. This paper investigated the possibility of introducing a futures markets for tradable P₂O₅ rights and the commodity manure. Because there is already a cash market for manure, although not well developed yet, and there will be a cash market for P₂O₅ rights, a futures market is a logical sequel. The futures market can play a role in implementing agricultural policy efficiently and with respect to manure and P₂O₅ rights can be an economically efficient solution to environmental problems.We acknowledge the financial support of the ATA (Agricultural Futures Market Amsterdam).     

Hedging and diversification across commodity assets

ABSTRACT

We investigate the conditional cross effects and volatility spillover between equity markets and commodity markets (oil and gold), Fama and French HML and SMB factors, volatility index (VIX) and bonds using different multivariate GARCH specifications considering the potential asymmetry and persistence behaviours. We analyse the dynamic conditional correlation between the US equity market and a set of commodity prices and risk factors to forecast the transmission of shock to the equity market firstly, and to determine and compare the optimal hedge ratios from the different models based on the hedging effectiveness of each model. Our findings suggest that all models confirm the significant returns and volatility spillovers. More importantly, we find that GO-GARCH is the best-fit model for modelling the joint dynamics of different financial variables. The results of the current study have implications for investors: (i) the equity market displays inverted dynamics with the volatility index suggesting strong evidence of diversification benefit; (ii) of the hedging assets gold appears the best hedge for the US equity market as it has a higher hedge effectiveness than oil and bonds over time; and (iii) despite these important results, a better hedge may be obtained by using well-selected firm sized and profitability-based portfolios.