Efficiency tests of agricultural commodity futures markets in China

The efficiency of the Chinese wheat and soybean futures markets is studied. Formal statistical tests were conducted based on Johansen's cointegration approach for three different cash markets and six different futures forecasting horizons ranging from 1 week to 4 months. The results suggest a long-term equilibrium relationship between the futures price and cash price for soybeans and weak short-term efficiency in the soybean futures market. The futures market for wheat is inefficient, which may be caused by over-speculation and government intervention.     

Measuring the functional efficiency of agricultural futures markets

This article presents a method for measuring the functional efficiency of agricultural futures markets in terms of social welfare using a standard futures market structural model. Employing the concept of social surplus, it can be shown that, when futures prices are used to estimate future spot prices, the errors in prediction produce to some degree resource misallocation, which in turn results in welfare losses. Therefore, the social welfare associated with the presence of futures markets can be measured using a Social Loss index. The indicator was calculated for the period 1975–2015 and for several subperiods, which allow us to analyse functional efficiency before and after the 2007–2008 spikes in the prices of agricultural commodities. Futures contracts for 12 products are evaluated. The products are grouped in three different categories: ‘soft products’, ‘livestock’ and ‘grains and oilseeds’. The results indicate that livestock contracts tended to be more efficient than the rest of the contracts during the whole period, but in 2008–2015 their efficiency decreased vis‐á‐vis the rest of the products. Nevertheless, 2008–2015 proved to be the most efficient subperiod, confirming the remarkable development of agricultural futures markets over time.     

Futures Markets and Spot Price Volatility: A Case Study

Futures markets, where they exist, can play a crucial role in determining the storage decision in the underlying spot (physical) market. The futures market acts as a conduit for market information and is a gatherer of agents' expectations about the future prospects for the spot market. As such, it is able to provide both price insurance and price discovery roles, the latter of which generates information for spot market traders and allows them to make rational storage decisions. If this were to be the case, then the efficiency of storage is improved which can potentially lead to a reduction in the volatility of spot prices over the marketing season. The existing literature is ambiguous as to whether futures markets can help spot markets price more efficiently. This paper seeks to examine whether this is the case in the British maincrop potato market by evaluating the volatility of spot prices over the period 1969–96 in a “before-after” analysis of the impact of the introduction of futures trading in 1980. The results suggest that the introduction of the futures market has led to a reduction in price volatility, despite some problems in the operation of the futures market itself.     

ASPECTS OF HEDGING THEORY

In this paper, interpretative comments are offered on some established aspects of the economics of futures trading, including the nature of the equilibrium condition in the case of an inverse carrying charge, some inferences about traders' market positions made from estimates of returns, and the implications of the normal backwardation hypothesis in cases where hedgers are net long. The paper also includes a survey of the recent literature on the forward pricing function of futures markets, with a discussion of, inter alia, the methods used to investigate the hypothesis that futures prices are anticipations of delivery date spot prices, and the possible reasons why some markets perform this function better than others.     

The market efficiency hypothesis: the case of coffee and cocoa futures

This study tests the market efficiency hypothesis for coffee and cocoa futures using daily data for contracts with a maturity of 2 and 6 months. The hypothesis is tested sequentially. The first condition is that future spot and futures prices be cointegraled. If this condition is maintained, market efficiency requires the cointegrating vector to support a (0, 1) restriction that can be likened to an unbiasedness condition. Finally, market efficiency imposes zero restrictions on the parameters of the variables expressed in first differences in the specification of the error-correction representation of the relationship between future spot and futures prices. Brenner and Kroner [Brenner, R., Kroner, K., 1995. Arbitrage, cointegration, and testing the unbiasedness hypothesis in financial markets. Journal of Financial and Quantitative Analysis 30, pp. 23–42] argue that the cointegration condition is rarely met in practice. They attribute this outcome to potentially non-stationary net cost-of-carry which would make the parameters of the cointegration relation unstable. It is for this reason that Hansen's tests [Hansen, B.E., 1992. Tests of parameter instability in regressions with I(1) processes. Journal of Business and Economic Statistics 10] about the stability of the parameters in cointegration regressions were used to supplement more traditional cointegration tests, Johansen and Juselius' cointegration tests [Johansen, S., Juselius, K., 1992. Testing structural hypotheses in a multivariate cointegration analysis of the PPP and the UIP for UK, Journal of Econometrics 53] could not reject cointegration for all four contracts while Hansen's L_C test favored cointegration only for the cocoa contracts. Nested and non-nested testing procedures were used to test the (0, 1) restriction on the cointegration vector. Unbiasedness was found to be robust across testing procedures. However, further testing about the specification of the error-correction representation revealed the existence of important short run deviations from unbiasedness, Even though these results hold strictly for a rather limited number of contracts and commodities, they are encouraging for futures markets advocates in developing countries.     

Did Futures Markets Stabilise US Grain Prices?

Though economists are divided over whether, in practice, futures markets reduce spot price volatility, observers of nascent nineteenth century US futures markets essentially praised the stabilising effects of this financial innovation. Indeed, such praise is understandable, particularly if, as the Chicago Board of Trade (CBOT) and others assert, “violent” spot price fluctuations were common prior to, but not after, the 1870s; the same decade that grain trade historians typically associate with the birth of the modern futures contract. And whereas these events may be unrelated, the claim is intriguing because it requires that nineteenth century futures prices fulfil their price discovery function, a property that many modern futures markets do not possess. This paper explores what role, if any, the advent of futures trading may have had on spot price volatility. I corroborate the CBOT's assertion regarding diminished spot price volatility around the 1870s and show that early futures prices did indeed fulfil their price discovery function. Moreover, I address two alternative hypotheses that relate the decline in spot price volatility to the Civil War. Ultimately, I maintain that the evolution of futures markets is the principal proximate reason why commodity spot price volatility diminished.     

Ride the trend: Is there spread momentum profit in the US commodity markets?

Some previous researchers have argued that trading strategies based on calendar spread time series momentum (STSM) can deliver significant returns (Szymanowska et al. 2014; Boons and Prado 2019), which, if true, is at odds with the efficient market hypothesis. These arguments however, do not exclude the unrealisable futures contract roll yield and are also affected by other empirical and statistical issues that may lead to misleading results. With more than 30 years of data, we investigate STSM in 22 US commodity futures markets. First, we assess whether past spread returns can predict future returns, a necessary condition for the existence of momentum. We find predictability to be very weak after correcting for the issues affecting prior research. Second, we implement STSM-based investment strategies. We compare STSM profits for individual markets and portfolios to profits generated by a simple long-only benchmark strategy that does not require any predictability. STSM does not generate returns statistically different from the benchmark trading strategy, with both strategies generating very low or negative returns. For the momentum to outperform the benchmark strategy, predictability should be three times larger than observed from real data, but would entail substantial downside risk. In sum, the empirical evidence indicates that returns from STSM-type strategies are illusive for the commodities and period studied. Our results strongly suggest that inclusion of unrealisable roll yield generates the illusion of profitable STSM trading strategies in previous research.     

Assessing the Vulnerability to Price Spikes in Agricultural Commodity Markets

We examine empirically the predictability of conditions associated with a higher probability of a price spike in agricultural commodity markets. We find that the forward spread is the most significant indicator of probable price jumps in maize, wheat and soybeans futures markets, a result which is in line with the ‘Theory of Storage’. We additionally show that some option-implied variables add significant predictive power when added to the more standard information variable set. Overall, the estimated probabilities of large price increases from our probit models exhibit significant correlations with historical sudden market upheavals in agricultural markets.     

Market liberalization and integration of maize markets in Malawi

The paper studies the extent of market integration of maize markets in Malawi in order to understand how it has been affected by market liberalization. Several measures of integration are introduced to analyze both the comovement of prices and the price adjustment process over time. Monthly retail prices of maize at eight main locations over the period January 1984 to December 1991 are considered. The main conclusion is that liberalization has increased market integration.     

Why do farmers have so little interest in futures markets?

A farm financial model with leverage and investment in two farm enterprises is specified. The model is extended to incorporate futures hedging and the Separation Theorem is used to show that optimal hedging is zero. The assumption of a risk‐free asset is relaxed and, while this leads to a violation of the Separation Theorem, the result that optimal hedging is zero is maintained providing that futures markets are efficient. It is concluded that if capital markets are efficient then farmers will have little interest in futures markets except to speculate.     

Pre-Harvest Price Expectations for Corn: The Information Content of USDA Reports and New Crop Futures

This article examines the puzzle of why futures prices continue to react to USDA crop reports despite the fact that reports appear to be no longer "newsworthy," that is, provide no better production estimates than private forecasts. The information value of reports is measured in terms of their influence on rational agents' harvest-time corn price expectations, which are uncovered using a Hamilton-type modeling approach. Results show that reports are still "newsworthy," as they would contribute to agents' price expectations if released a day early. Thus futures price reactions, which closely reflect price expectations, are rational and consistent with efficient markets hypothesis.     

Commodity index investment and food prices: does the “Masters Hypothesis” explain recent price spikes?

The “Masters Hypothesis” is the claim that unprecedented buying pressure in recent years from commodity index investors created massive bubbles in food and energy prices. The purpose of this article is to review the evidence from recent studies that investigate the empirical relationship between index investment and price movements in agricultural futures markets. One line of research uses time‐series regression tests, such as Granger causality tests, to investigate the relationship between price movements and index positions. This research provides little evidence in support of the Masters Hypothesis in agricultural futures markets. A second line of research uses cross‐sectional regression tests and studies in this area provide very limited evidence in favor of the Masters Hypothesis for agricultural futures markets. A third line of research investigates whether there is a significant relationship between commodity index trading and the difference, or spread, between futures prices of different contract maturities on the same date. These studies report a range of results depending on the type of test. However, the bulk of the evidence indicates either no relationship or a negative relationship, which is once again inconsistent with the Masters Hypothesis. Overall, this growing body of literature fails to find compelling evidence that buying pressure from commodity index investment in recent years caused a massive bubble in agricultural futures prices. The Masters Hypothesis is simply not a valid characterization of reality.     

Bubbles,Froth and Facts: Another Look at the Masters Hypothesis in Commodity Futures Markets

The Masters Hypothesis suggests that long‐only index funds were the main cause of a massive increase in commodity prices in 2007–2008 and 2011–2012. Central to the Masters Hypothesis are three basic tenets: (i) long‐only commodity index funds were directly responsible for driving futures prices higher; (ii) the deviations from fundamental value were economically very large; (iii) the impact was pervasive across commodity futures markets. There has been a great deal of empirical research on the Masters Hypothesis and commodity market bubbles. However, surprisingly few studies have found evidence that directly support the main tenets of the Masters Hypothesis. Some have attributed the lack of supporting evidence to the low‐power of time‐series tests, market efficiency issues and a lack of conditioning variables within models. In this paper, we address each of these issues using updated data and new empirical approaches. Still, price behaviour consistent with the Masters Hypothesis is surprisingly difficult to find in the data. This is an important finding given the on‐going policy debate and regulations proposed or being implemented to limit speculative positions in these markets.     

中加菜籽油期货市场波动溢出实证研究

利用误差修正模型、BEKK-GARCH模型和格兰杰因果关系实证研究了加拿大和中国菜籽油期货市场之间的信息传导、波动溢出和价格引导关系。实证结果显示：这两个市场之间存在一定的信息传导关系;加拿大菜籽油期货市场对中国菜籽油期货市场存在显著的波动溢出效应,而中国菜籽油期货市场对加拿大菜籽油期货市场的波动溢出不显著;短期内加拿大菜籽油期货市场对中国菜籽油期货市场的价格引导作用更强些,这与加拿大菜籽油期货市场是全球菜籽油定价中心的实际相吻合,而中国菜籽油期货市场的竞争力有待进一步提升。     

How Reliable Are Hog Futures as Forecasts?

The Chicago Mercantile Exchange hog futures contract was revamped in 1997 and it is one of the largest futures markets for a nonstorable commodity. The literature is divided on whether or not futures prices for nonstorables provide reliable forecasts of cash prices. We find that from 1998 to 2004, the hog futures market was an unbiased predictor of cash prices.     

Causality and Efficiency in the Coffee Futures Market

Tests for causality and rationality in the coffee futures market were carried out using data from the New York Market. Tests of causality indicated that futures prices strongly influence variations in spot price eight weeks or more to maturity. However, beginning seven weeks to maturity there seems to be a strong causal relationship going from futures to spot and from spot to futures. Risk constancy or neutrality, equality of risk premium and spot price, and efficiency were rejected for the period 18, 51, and 33 weeks or more to maturity. However, simultaneity of risk neutrality and efficiency was accepted for contracts with 55-77 weeks to maturity. The general conclusion from this study is that coffee futures market can be used as an indicator of spot market prices for contracts with 55-77 weeks to maturity. While benefits can be obtained through short term adjustment of available stock and making use of quality storage facilities, planning longer term planting and marketing decisions (e.g., ≥ 77 weeks) on the basis of futures market price can result in misallocation of resources and welfare loss.     

Commodity futures markets: a survey

This review article describes the main contributions in the literature on commodity futures markets. It is argued that modern studies have focused primarily on technical questions, with insufficient economic content. More research needs to be directed towards understanding fundamental economic issues such as why so few farmers hedge, the impacts of government farm programs on commodity futures, and the market impacts of commodity pools. The literature has failed to explain the prevalence of inverted markets in grains and oilseeds, and there is unexplainable price volatility in markets such as hogs and orange juice.     

A speculative bubble in commodity futures prices? Cross‐sectional evidence

Recent accusations against speculators in general and long-only commodity index funds in particular include: increasing market volatility, distorting historical price relationships, and fueling a rapid increase and decrease in the level of commodity prices. Some researchers have argued that these market participants—through their impact on market prices—may have inadvertently prevented the efficient distribution of food aid to deserving groups. Certainly, this result—if substantiated—would counter the classical argument that speculators make prices more efficient and thus improve the economic efficiency of the food marketing system. Given the very important policy implications, it is crucial to develop a more thorough understanding of long-only index funds and their potential market impact. Here, we review the criticisms (and rebuttals) levied against (and for) commodity index funds in recent U.S. Congressional testimonies. Then, additional empirical evidence is added regarding cross-sectional market returns and the relative levels of long-only index fund participation in 12 commodity futures markets. The empirical results provide scant evidence that long-only index funds impact returns across commodity futures markets.     

Estimating Policy Effects on Spatial Market Eff iciency: An Extension to the Parity Bounds Model

The standard parity bounds model (PBM) is extended to allow for dynamic shifts in regime probabilities in response to changes in marketing policy. The approach allows estimation of the length of the adjustment period and a statistical test for no policy effects. The extended PBM is applied to maize and wheat markets in Ethiopia. Evidence of a dynamic adjustment path is found and grain marketing reforms are found to have improved spatial efficiency in a few markets, worsened it in a few others, but generally to have had little effect on the spatial efficiency of Ethiopian grain markets.     

Dynamic relationships between US and Thai rice prices

Relationships between the United States Department of Agriculture's (USDA) estimated World Market Price, the Thai milled rice price, US transportation-adjusted cash rough rice price, and the Chicago Rice and Cotton Exchange rough rice futures price are examined for the 1987–1991 marketing years. Specifically, a cointegration analysis is used to address the pricing and informational efficiency of the respective markets. Testing indicates the system is described by two cointegrating vectors. The analysis preformed herein provides insight into the pricing performance of several world rice markets.