A hybrid commodity price‐forecasting model applied to the sugar–alcohol sector

Accurate price forecasting for agricultural commodities can have significant decision‐making implications for suppliers, especially those of biofuels, where the agriculture and energy sectors intersect. Environmental pressures and high oil prices affect demand for biofuels and have reignited the discussion about effects on food prices. Suppliers in the sugar–alcohol sector need to decide the ideal proportion of ethanol and sugar to optimise their financial strategy. Prices can be affected by exogenous factors, such as exchange rates and interest rates, as well as non‐observable variables like the convenience yield, which is related to supply shortages. The literature generally uses two approaches: artificial neural networks (ANNs), which are recognised as being in the forefront of exogenous‐variable analysis, and stochastic models such as the Kalman filter, which is able to account for non‐observable variables. This article proposes a hybrid model for forecasting the prices of agricultural commodities that is built upon both approaches and is applied to forecast the price of sugar. The Kalman filter considers the structure of the stochastic process that describes the evolution of prices. Neural networks allow variables that can impact asset prices in an indirect, nonlinear way, what cannot be incorporated easily into traditional econometric models.     

The transmission of world maize price to South African maize market: a threshold cointegration approach

This article seeks to provide an explanation for the relationship between domestic maize price in South Africa and world maize prices in order to evaluate comovement and transmission of world prices to domestic prices in sub‐Sahara African countries. This is done by comparing nested and nonnested models that capture different forms of nonlinearity in the price spread. Adopting a Bayesian approach that allows for comparison of models using Bayes factor, we found that the relationship between South African price and world price for maize indicates the presence of nonlinearity in price transmission with three regimes that is triggered by the price spread in previous period.     

Nonlinearities in the U.S. corn‐ethanol‐oil‐gasoline price system

We use a smooth transition vector error correction model to assess price relationships within the U.S. ethanol industry. Monthly ethanol, corn, oil, and gasoline prices from 1990 to 2008 are used in the analysis. Results indicate the existence of long‐run relationships among the prices analyzed. Strong links between energy and food prices are identified.     

The Welfare Economics of a Biofuel Tax Credit and the Interaction Effects with Price Contingent Farm Subsidies

A framework is developed to analyze the effects of a biofuel consumer tax exemption and the interaction effects with a price contingent farm subsidy. Ethanol prices rise above the gasoline price by the amount of the tax credit. Corn farmers gain directly while gasoline consumers only gain from any reduction in world oil prices due to the extra ethanol production. Domestic oil producers lose. Historically, the intercept of the ethanol supply curve is above the gasoline price. Hence, part of the tax credit is redundant and represents "rectangular" deadweight costs that dwarf triangular deadweight cost measures of traditional farm subsidies.     

Price formation in the German biodiesel supply chain: a Markov‐switching vector error‐correction modeling approach

Changing linkages between agricultural and energy markets have attracted considerable attention in research and policy discussions during recent years. As one of the largest biofuel markets worldwide, the German biodiesel market is of particular interest. It has grown rapidly since the beginning of the new millennium, with this growth being driven mainly by political interventions. Vertical price transmission channels along the biodiesel supply chain are analyzed in this study. We examine the relationship between diesel and biodiesel prices, and between rapeseed oil, soy oil, and biodiesel prices between 2002 and 2008. Due to pronounced changes in market conditions and the policy framework, a regime‐dependent Markov‐switching vector error‐correction model is used. The regimes are characterized by markedly different price adjustment behaviors. Before 2005 and from late 2007 onward, a regime characterized by the strong orientation of biodiesel prices toward diesel prices dominates. Between 2005 and 2007, biodiesel and rapeseed oil prices are mutually interdependent. Frequent switches between the regimes of the price dynamics during this period indicate a high extent of uncertainty and instability in the market.     

Transaction Cost Thresholds in International Rice Markets

Recent episodes of high and volatile prices for grains such as rice have raised concerns about their implications for hunger and poverty. We model price relationships between international rice prices and 221 domestic prices in 47 developing countries that import rice. We use a threshold vector error correction model that accounts for transaction costs of trade in spatial price transmission, and an improved regularised Bayesian threshold estimator for threshold models. Our results show that threshold values are higher after 2008 than before, which suggests that transaction costs in international rice trade have increased in recent years. Threshold values are highest for Latin American countries followed by African and Asian countries, and higher for retail than for wholesale prices. Since 2008, price transmission is slower in countries that responded to high and volatile prices with domestic market‐based interventions such as price controls and faster in countries that responded by lowering tariffs and by implementing production support measures.     

Price transmission between products at different stages of manufacturing in forest industries

The theory of demand and supply implies a positive relationship, or “price transmission” between the prices of products at different stages of manufacturing. This relationship was investigated with quarterly prices of softwood stumpage in the US South, and national prices of forest products, from 1977 to 2002. All prices, net of inflation, were found to be nonstationary and there was no evidence of co-integration between prices. Vector autogressive models, augmented by Granger causality tests and multiplier analysis showed that there was a one-to-one permanent positive response of the southern sawtimber stumpage price to a permanent change in the national lumber price. There was also a one-third permanent positive response of the national paper price to a permanent change in the national pulp price. There was no relation between regional pulpwood prices and national pulp or paper prices. When price transmission was significant, the full adjustment took about 2 years.     

The integration of energy and agricultural markets

This article addresses the evolving links between energy and agricultural markets. Prior to 2005, there was little correlation between energy and agricultural commodity prices. In 2006–2008, with the ethanol boom in the United States, there emerged a strong link between crude oil, gasoline, and corn prices. There was little link between ethanol and corn. However, in late 2008 and 2009, the markets changed as ethanol production came under severe economic pressure and 2 billion out of 12 billion gallons of capacity shut down. During this period ethanol became priced more on corn, as the breakeven corn price helped drive the ethanol market. This article explores the drivers in these markets as well as other major issues facing the corn ethanol industry in the United States such as the blend wall. The article concludes with a review of prospects of a future cellulosic biofuels industry.     

Competitive Storage,Biofuels and the Corn Price

The use of corn as an ethanol feedstock has been stimulated by US biofuels policy. This has changed both the position and the slope of the corn demand curve and increased the pass-through from crude oil to corn prices. The principal constraints on ethanol consumption and production have been regulation (the biofuels mandate), capacity constraints in ethanol refining and the blend wall, which puts a ceiling on the ethanol content of gasoline. The incidence of these constraints has varied over time. We model these impacts within the competitive storage model using structural break regression analysis. Our analysis shows that the pass-through has varied over time in relation to the share of ethanol in total US corn use. Our analysis provides robust empirical evidence of an increase in the pass-through from crude oil to corn prices over the period from the start of the century to a high level over 2004–2008 when corn use in ethanol was growing very fast. This enhanced sensitivity was driven by competition for corn as an ethanol feedstock with stock demand exerting strong upward pressure on the corn price.     

SUPPLY RESPONSE OF AUSTRALIAN WHEAT GROWERS

Alternative specifications of models of the supply response of Australian wheat growers and their economic implications are considered in terms of the existence and nature of production lags, and the choice between expected prices and expected gross returns as the preferred explanator of producers' response to changing economic conditions. The analysis indicates that there are lags which are due primarily to the difficulties and costs of rapid adjustment rather than to the time required to revise expectations. The statistical results were similar for the alternative specifications of gross margins and prices as the economic decision variables. However, the price elasticities derived using the gross margins specification were about a third of those using the prices specification. The gross margins specification yielded additional information in the form of yield and input cost elasticities.     

Threshold Effects in Price Transmission: The Case of Brazilian Wheat, Maize, and Soya Prices

Recent studies into price transmission have recognized the important role played by transport and transaction costs. Threshold models are one approach to accommodate such costs. We develop a generalized Threshold Error Correction Model to test for the presence and form of threshold behavior in price transmission that is symmetric around equilibrium. We use monthly wheat, maize, and soya prices from the United States, Argentina, and Brazil to demonstrate this model. Classical estimation of these generalized models can present challenges but Bayesian techniques avoid many of these problems. Evidence for thresholds is found in three of the five commodity price pairs investigated.     

The role of retail market power and state regulations in the heterogeneity of farm‐retail price transmission of private label and branded products

Given the leading role of private label brands in the fluid milk market, it is of special interest to focus on possible differences in farm‐retail price transmission between private label and branded milk as well as the causes of heterogeneity. This article examines the heterogeneous effects of private label and branded products on price transmission in the fluid milk market using a panel threshold asymmetric error correction model. Results indicate that upward retail‐price adjustment is faster than the downward price adjustment for both private label and branded milk. The speed of adjustment of private label products is significantly faster than branded products in three different price regimes. We further investigate the reasons of heterogeneity in farm‐retail price transmission of private label milk. We find that both retailer market power and state pricing regulations contribute to the heterogeneity in asymmetric price transmission. Higher retailer market power causes retail prices of private label milk to rise faster and to fall slower. The existence of a state pricing regulation slows down the adjustment speed of retail prices of private labels back to the long‐run equilibrium, regardless of whether the retail price is low or high.     

Transmission of price shifts in the context of structural adjustment: An empirical analysis for staple food after the devaluation of the franc CFA in Ivory Coast

This article analyses price shifts after currency devaluation in the Ivory Coast using a time‐series modelling approach. Model results identify the liberalisation of the import‐rice sector as the key factor for the transmission of price effects. Fixation of the imported rice price as a social compensatory measure hindered the adjustment of prices in the first year after the devaluation. As soon as the price controls on imported rice were lifted, prices changed in favour of tradable goods. The findings in this paper hint at a possible trade‐off between the protection of vulnerable groups during the process of adjustment and the intended incentive effect.     

Price shock transmission: evidence from the wheat‐bread market value chain in Ethiopia

This study assesses the degree of vertical price transmission along the wheat‐bread value chain in Ethiopia. This is pursued by applying a vector error correction model and an impulse response analysis using monthly price data for the period 2000–2015. Our analysis considers transmission of price shocks across different market levels, including from the international and domestic wheat grain markets at the upstream to the domestic wheat bread market at the downstream of the value chain. The empirical findings indicate that significant cointegration exists across prices of the different market stages. There is a transmission from international prices to domestic prices at downstream markets, in particular to flour and bread prices. Prices at upstream markets are largely influenced by the domestic wholesale market. In general, the speed of adjustment is quite slow with a half‐life of about one year for restoring the equilibrium price relationship. As price margins between the different market stages in the value chain have substantially decreased in the last 15 years, higher transmission, and thus exposure to international market shocks, can be expected in the future. The results also show that causal relationships exist between prices at different market stages—with the wholesale market identified as the key market level where prices and price expectations are formed.     

El Niño southern oscillation and its effects on world vegetable oil prices: assessing asymmetries using smooth transition models

In this research, we examine the effects of El Niño southern oscillation (ENSO) on market dynamics of major vegetable oil prices. We adopt a smooth transition vector error correction modelling framework to analyse the impacts of ENSO events on the vegetable oil prices and, more interestingly, to investigate the asymmetric nature of the ENSO dynamics and price responses to ENSO shocks. The results confirm self‐exciting type nonlinearities in the ENSO dynamics, and presence of the so‐called transactions cost band in the system of vegetable oil prices. These nonlinearities yield the history‐specific asymmetries in the vegetable oil price dynamics, wherein effects of ENSO shocks on the ENSO dynamics and the vegetable oil prices vary considerably between different ENSO regimes. In general, positive deviations, El Niño events, result in the vegetable oil price increase, while negative deviations, La Niña events, result in decrease in the prices. We illustrate these effects using generalised impulse‐response functions and the derived asymmetry measures.     

上海原油期货价格与我国新能源股价的相关性研究

选取上海原油期货和中证新能指数作为研究对象,以VAR模型为基础,分析了原油期货价格对新能源行业股价产生的引导作用,研究了上海原油期货与我国新能源行业股价的相关关系。研究结果表明:①上海原油期货价格的下跌会引起我国新能源行业股价的上涨,两者表现出反向变动;②上海原油期货价格对新能源行业股价的贡献率在不断提高,相互影响程度逐渐增强。     

Measuring the Impact of Ethanol Plants on Local Grain Prices

A considerable number of farmer-owned ethanol plants have been built in the past few years, with many more planned. In part, farmers' investment in ethanol plants is an attempt to increase grain prices in their local market. We examined this issue by estimating the impact on local grain prices of twelve ethanol plants that opened from 2001 to 2002. We find that these new ethanol plants increased local grain prices, but the impact was not uniform around the plant. Markets downstream from a new plant, where prices tend to be higher, experienced a smaller price impact from the ethanol plant. On average across plants, corn prices increased by 12.5 cents per bushel at the plant site, and some positive price response was felt 68 miles away from the plant.     

中国木本食用油料价格波动规律分析——以油茶、核桃为例

以木本食用油料油茶、核桃为例,利用季节调整法、H-P滤波等方法对2002²010年油茶、核桃的季度收购价格进行波动性分析结果表明:这两种木本食用油料的收购价格均呈现出上升的长期趋势,具有明显的季节性波动,且易受到外部因素的冲击;20022010年油茶、核桃的季度收购价格进行波动性分析结果表明:这两种木本食用油料的收购价格均呈现出上升的长期趋势,具有明显的季节性波动,且易受到外部因素的冲击;2002²010年油茶籽、核桃收购价格均经历了5次明显的周期波动,同时波动周期具有不可重复性和非对称性。木本食用油料自身的季节供应以及物理属性、自然因素等随机冲击、技术进步和消费者对绿色、健康的木本食用油需求的拉动效应以及木本食用油生产成本的推动效应影响木本食用油料价格的波动。     

Spatial price premium transmission for Meat Standards Australia‐graded cattle: the vulnerability of price premiums to outside shocks

Studies of market integration show that price changes are transmitted spatially through arbitrage. Transmission across differentiated agricultural products is important to investigate, but it has not been explored given its complexities for assessment. Using data from Australian cattle markets, we examine the dynamics of Meat Standards Australia price premium transmission between states. An impulse response function analysis using Bayesian vector autoregression with sign restriction identification shows that shocks to prices and price premiums are partially transmitted contemporaneously between markets and it takes several weeks to complete transmission. In addition, we find an asymmetry of price and price premium shocks originating in Southern Queensland that have an inverse immediate impact in New South Wales, and take months to transmit the usual price response. This outcome may be explained by differences in cattle availability in each state, which can be related to forage availability due to weather conditions. Based on these results, producers can forecast fluctuations on price premiums and adjust their cattle supply accordingly.     

Fighting global food price rises in the developing world: the response of China and its effect on domestic and world markets

This article addresses how China is being affected by and is responding to the world food crisis. So far, Chinese officials have responded to higher world prices by drawing down stocks and limiting exports of major grains. These policy instruments were not available for soybeans, so domestic prices of soy and other oilseeds have risen with international prices. Using a global CGE model, we show that the initial world price rise was largely due to higher world oil prices and demand for biofuels as opposed to other factors, especially in maize and soybeans. China's response to this shock has kept domestic grain prices low relative to world grain markets and to domestic soybean prices. As grain stocks are depleted, however, demand growth will push domestic prices back into alignment. Anticipating this pressure on consumers and accelerating supply response through public investment will facilitate adjustment.