我国粮食市场价格波动特征——基于ARCH类模型的实证分析

基于1998年1月9日至2012年12月14日全国小麦、玉米和大豆的批发价格指数周数据,利用ARCH类模型对我国小麦、玉米和大豆的市场价格波动特征进行实证分析。研究结果表明:在5%的显著性水平下,小麦、玉米和大豆的市场价格波动具有明显的时变性和集簇性;玉米市场具有高风险、高回报的特征;小麦的市场价格波动具有非对称性;玉米市场与大豆市场之间存在显著的双向价格波动溢出效应。     

A cointegration analysis of agricultural,energy and bio-fuel spot,and futures prices

This article features an analysis of the cointegration relationships among agricultural commodity, ethanol and Cushing crude oil spot, and future prices. The use of grains for the creation of bio-fuels has sparked fears that these demands are inflating food prices. We analyse approximately 10 years of daily spot and futures prices for corn, wheat, sugar ethanol, and oil prices from Datastream for the period 19 July 2006 to 2 July 2015. The analysis features Engle-Granger pairwise cointegration and partial cointegration. Pairs of series, that are cointegrated, are analysed using Markov-switching VECM and Impulse Response Analysis, which confirms that these markets have significant linkages that vary according to whether they are in low or high volatility regimes.     

Correlation dynamics of crude oil with agricultural commodities: A comparison between energy and food crops

This study elucidates plausible correlation between crude oil and agricultural commodities. We assess whether the conditional correlation of crude oil with energy crops (e.g., corn and soybeans) is different from that of food crops (e.g., oats and wheat). We find a stronger correlation of about 20 percent between returns of crude oil and energy crops. However, the correlation coefficient value for oil-oats and oil-wheat is as low as eight percent. We add to the literature by exploring correlation in a dynamic context using three different GARCH models and found that conditional correlation between crude oil and energy corps is relatively high. In order to reduce risk associated with crude oil price fluctuations, this study also examined hedging possibilities against crude oil by investment in agricultural commodities. Although hedging effectiveness is low with all underlying agricultural commodities, soybeans provide relatively better hedging possibilities compared to other agricultural crops.     

Oil price and automobile stock return co-movement: A wavelet coherence analysis

This paper explores possible co-movement between oil price and automobile stock return in a joint time-frequency domain. Daily price series from August 01, 1996 to June 20, 2017 is used in this analysis. The results indicate that the co-movement between oil price and automobile stock return is strong during November, 2000–December, 2002 and March, 2006–December, 2009. The co-movement is found to be more pronounced in the long-term and stock return is sensitive to the higher oil price emanating from the demand shock. This contravenes the conventional wisdom that crude oil is always counter-cyclical to the automobile stocks. For investor, this weakens the probable gain from including oil asset in a portfolio of automobile stocks as crude oil does not offer cushion against bearish automobile stock markets during the crisis period.     

A common factor of stochastic volatilities between oil and commodity prices

This article analyses the multivariate stochastic volatilities (SVs) with a common factor influencing volatilities in the prices of crude oil and agricultural commodities, used for both biofuel and nonbiofuel purposes. Modelling the volatility is crucial because the volatility is an important variable for asset allocation, risk management and derivative pricing. We develop a SV model comprising a latent common volatility factor with two asymptotic regimes with a smooth transition between them. In contrast to conventional volatility models, SVs are generated by the logistic transformation of latent factors, which comprise two components: the common volatility factor and an idiosyncratic component. We present a SV model with a common factor for oil, corn and wheat from 8 August 2005 to 10 October 2014, using a Markov chain Monte Carlo method to estimate the SVs and extract the common volatility factor. We find that the volatilities of oil and grain markets are persistent. According to the estimated common volatility factor, high volatility periods match the 2007–2009 recession and the 2007–2008 financial crisis quite well. Finally, the extracted common volatility factor exhibits a distinct pattern.     

Intermarket spread opportunities between Canadian and American agricultural futures

This study extends Carter's (1989) study of the efficiency of Canadian canola and American soybean oil futures markets during 1981–1987 to a new period (1988–1993). It also uses a different spread strategy than Carter to see if the same conclusions hold for canola and soybean as well as Canadian feed wheat and American wheat futures. Our findings confirm that in the 1981–1987 period there were no opportunities for intermarket spread profit between canola and soybean oil futures and between feed wheat and wheat futures. Our findings for the period 1988–1993, however, suggest there were some opportunities for such profits. Thus, it was possible for floor traders (and possibly institutional investors), who paid low transaction costs, to experience some additional profits. We also find that these opportunities are neither due to changes in currency values over time, nor to the use of weekly or daily exchange rates. Nevertheless, nonparametric tests show that spread profits are statistically insignificant.     

Financial illness and political virus: the case of contagious crises in the Eurozone

Abstract

This paper investigates the volatility spillover effects from the southern to northern part of the Eurozone during the sovereign debt crisis. Focusing on different phases of the crises, we propose using the dynamic conditional correlation model and the BEKK model to identify possible linkages during the period of 2005–2015. The findings showed that both models behave satisfactorily and are flexible in presenting spillover effects. However, regarding conditional correlations, the asymmetric dynamic conditional correlation model seems to fit better. Additionally, Spain and Italy can significantly damage all strong northern economies, while Greece’s negative shocks are capable of co-moving the French index. Finally, France is the most correlated country within the southern Eurozone.     

Interdependencies in the energy–bioenergy–food price systems: A cointegration analysis

The present paper studies the interdependencies between the energy, bioenergy and food prices. We develop a vertically integrated multi-input, multi-output market model with two channels of price transmission: a direct biofuel channel and an indirect input channel. We test the theoretical hypothesis by applying time-series analytical mechanisms to nine major traded agricultural commodity prices, including corn, wheat, rice, sugar, soybeans, cotton, banana, sorghum and tea, along with one weighted average world crude oil price. The data consists of 783 weekly observations extending from January 1994 to December 2008. The empirical findings confirm the theoretical hypothesis that the prices for crude oil and agricultural commodities are interdependent including also commodities not directly used in bioenergy production: an increase in oil price by 1 $/barrel increases the agricultural commodity prices between 0.10 $/tonne and 1.80 $/tonne. Contrary to the theoretical predictions, the indirect input channel of price transmission is found to be small and statistically insignificant.     

美国生物乙醇产业发展面临的挑战

美国生物乙醇产业的发展已经势不可挡,美国各界也基本认同了美国政府向农业要能源的发展战略.但是,生物乙醇产业的大规模发展将遇到多种挑战.     

Financial contagion and volatility spillover: An exploration into Indian commodity derivative market

This study measures the extent of financial contagion in the Indian asset markets. In specific it shows the contagion in Indian commodity derivative market vis-à-vis bond, foreign exchange, gold, and stock markets. Subsequently, directional volatility spillover among these asset markets, have been examined. Applying DCC-MGARCH method on daily return of commodity future price index and other asset markets for the period 2006–16, time varying correlation between commodity and other assets are estimated. The degree of financial contagion in commodity derivative market is found to be the largest with stock market and least with the gold market. A generalized VAR based volatility spillover estimation shows that commodity and stock markets are net transmitters of volatility while bond, foreign exchange and gold markets are the net receivers of volatility. Volatility is transmitted to commodity market only from the stock market. Such volatility spillover is found to have time varying nature, showing higher volatility spillover during the Global Financial Crisis and during the period of large rupee depreciation in 2013–14. These results have significant implication for optimal portfolio choice.     

The effect of the 2007 ethanol mandate on downside risk in agriculture: evidence from Kansas farmers

The Energy Independence and Security Act of 2007 increased the amount of corn ethanol that must be blended into motor vehicle and other fuels as part of the renewable fuel standard. The purpose of this article is to look at how the increase in demand for corn influenced the profitability and downside risk of farms. We conducted this investigation using annual data for more than 300 farms in Kansas from 1997 through 2014. We find that the probability of a farmer’s experiencing a negative return on equity (i.e. the ‘downside risk’ of farming) decreased by 25 percentage points after 2007.     

Long-run waves or short-run fluctuations – what establishes the correlation between oil and food prices?

The strong correlation between food prices and energy prices has gained much attention in the public debate. In this article, we focus on the so-called excess co-movement, which is the correlation between crude oil price and the prices of food commodities after controlling for economic activity. We use a frequency domain Granger causality test to analyse short-run and long-run relationships between crude oil prices and prices of food commodities. For important biofuel inputs like maize, soybeans, rapeseed and EU sugar, we find evidence for long-run Granger causality in particular for the period after 2007. This supports the hypothesis that the increasing biofuel production creates the link between the prices of crude oil and food commodities. However, we also find short-run Granger causality for various food commodities. This result is more in line with herd behaviour or speculation in commodity markets.     

Return and volatility spillovers between china and world oil markets

We examine return and volatility spillovers between China and world oil markets. This topic is of great importance because China is the world's second-largest oil importer and has exhibited substantial growth in oil consumption. Extending Diebold and Yilmaz's (2012) method of catching spillover dynamics, it is found that return and volatility spillovers between China and world oil markets are bi-directional and asymmetric. The Chinese oil market is highly affected by world oil markets and exerts an influence on world oil markets, although to a lesser extent. Moreover, the volatility spillover index has increased significantly since the peak of the last financial crisis in September 2008. Although the US oil market impacts China's market most in terms of spillover, the influence of China's oil market on the world oil market has intensified in recent years.     

Covariance breakdowns and connectedness of crude oil futures markets with non-synchronous data

ABSTRACT

This article identifies the breakdowns in the covariance of three benchmark crude oil futures markets (WTI, Brent and Dubai) and investigates the changes of market connectedness across the breakdown periods. As the crude oil futures are traded in different regions, this article eliminates the non-synchronous trading data by employing the Vector Moving Average structure and the Bayesian data augmentation approach, which keeps the integrity of original data without changing its properties. The results show that there are significant breaks in the covariance structure of crude oil futures markets. The breakdown periods are consistent with the periods when the market volatilities are at high level and the returns are volatile. The changes of market connectedness are independent of the covariance states, which supports the globalization hypothesis for the crude oil market. The results also suggest that there is more information flow out of the WTI than to the WTI during the sample period, particularly during the breakdown periods in 2008–2009.     

Risk attitudes and premiums of U.S. corn and soybean producers: an empirical investigation

The 2000 Agricultural Risk Protection Act and 2002 Farm Security and Rural Investment Act reduced price and yield risks faced by many U.S. crop producers to low levels. We use a non-structural methodology extended for application to pseudo panels and national survey data to examine the risk attitudes of U.S. corn and soybean producers to test whether, and examine how, risk attitudes varied during the 1996–2001 and 2002–2008 periods by revenue category. We cannot reject the hypothesis of risk neutrality for the entire population, and for each revenue category, for the former period, but can reject risk neutrality, in favor of risk tolerance, for the entire population and for the larger revenue categories for the latter period. Estimated risk premiums for the latter period suggest that U.S. corn and soybean farmers who earn more require larger payments to remain indifferent between receiving their expected income with certainty and receiving an uncertain income from farming and government programs.     

Biofuels and Land Use Change: Sugarcane and Soybean Acreage Response in Brazil

Scientists and economists are increasingly worried that biofuels production is leading to land use changes in the form of competition with food crops or loss of natural ecosystems. I estimate acreage conversion in response to shocks in sugarcane (a biofuels feedstock) and soybean (thought to be affected by United States corn ethanol production) prices in Brazil at a national and regional level. Using county-level data from 1973 to 2005, I consider a dynamic panel data model of input demand for agricultural land, conditioning on price changes of other commodities. The short-run crop-price elasticity of sugarcane acreage in Brazil is estimated to be approximately zero, whereas the elasticity of soybean acreage is 0.9 when both spot and futures prices change. The regional estimates for soybeans show considerable variation, and are highest in areas of ecological importance, such as the cerrado. Sugarcane estimates are more homogeneous. These results should be taken into account in impact assessments of biofuels.     

Do firms with larger patent portfolios create more new plant varieties in the US agricultural biotechnology industry?

This article is an empirical analysis of the relationship between patent ownership and variety innovation for US agricultural biotechnology firms in the years 1976–1999. Counts of new varieties include corn, soybean, or wheat varieties protected by either patents or plant variety protection certificates, while patent portfolio size is defined as the count of a firm's gene and method patents. Negative binomial regression results indicate that firms with larger patent portfolios did not exhibit scale economies in variety creation nor did firms with wider technological diversity in their patent portfolios create significantly greater numbers of new varieties. However, firms experienced positive spillover effects from rival firms’ patent ownership, and patent ownership increases this effect. Sample firms that have merged in the past do not produce significantly greater numbers of new varieties after considering an increase in portfolio size and did not experience greater economies of scale in creating new varieties compared with firms that experienced no past mergers.     

How does spatial crowdedness affect patenting performance in industrial clusters? An empirical study on the moderated U-shaped relationship

ABSTRACT

Prior literature suggests the coexistence of the positive and the negative externalities of agglomeration. However, with a focus on the production system side of industrial cluster, the extant studies less explore the root of the above mixed findings from the knowledge system side of clusters. Thus, this study aims to establish a coherent theoretical framework to reconcile the mixed findings on the relationship between spatial crowdedness and cluster-level patenting performance. Specifically, we expect a U-shaped relationship between spatial crowdedness and cluster-level patenting performance. From a perspective of knowledge based view, we argue that the interplay of two underlying mechanisms, i.e. knowledge spillover exploitation and knowledge safeguarding, will lead to this U-shaped relationship. We also propose the moderation effect of technological complexity on this U-shaped relationship. Using a longitudinal dataset from a sample of 171 industrial clusters in China during the period of 2011–2015, we find strong supports to our hypotheses.     

Quantile spillovers and dependence between Bitcoin,equities and strategic commodities

This paper has two aims. We first examine the dynamic spillovers between Bitcoin and 12 developed equities, gold, and crude oil for different market conditions using a Bayesian Time-Varying Parameter Vector Autoregressive (TVP-VAR) model with daily spot prices. Our econometric approach enables us to capture the left and right tails as well as the shoulders of the return distribution corresponding to volatility spillovers under the bear, normal, and bull market states among these financial assets. We quantify and trace the dependence and directional predictability from Bitcoin to other assets using the sample cross-quantilogram. Our key findings offer convincing evidence of time variation in the level of volatility. Spillovers between Bitcoin and other financial assets intensify during extreme global market conditions. Secondly, results from the cross-quantilogram indicate strong dependence and positive directional predictability between Bitcoin and most equities and crude oil when market returns are bullish. However, during the bearish market period, there is negative dependence and predictability from Bitcoin to stocks in Finland, the Netherlands, the U.S.A, and the crude oil market only. This implies that Bitcoin can act as a hedge to stocks in Finland, the Netherlands, the U.S.A, and the crude oil market. However, insignificant dependence and directional predictability from Bitcoin to the remaining assets indicate that Bitcoin may act as a safe-haven to these assets during bearish markets. Our findings hold important implications for both international investors and portfolio managers who consider Bitcoin as part of their portfolio diversification and other investment strategies.     

Farm Acreage Shocks and Crop Prices: An SVAR Approach to Understanding the Impacts of Biofuels

The last 10?years have seen tremendous expansion in biofuels production, particularly in corn ethanol in the United States, at the same time that commodity prices (e.g., corn) have experienced significant spikes. While supporters claim that biofuels are renewable and carbon-friendly, concerns have been raised about their impacts on land use and food prices. This paper analyzes how US crop prices have responded to shocks in acreage supply; these shocks can be thought of as a shock to the residual supply of corn for food. Using a structural vector auto-regression framework, we examine shocks to a crop??s own acreage and to total cropland. This allows us to estimate the effect of dedicating cropland or non-crop farmlands to biofuels feedstock production. A negative shock in own acreage leads to an increase in price for soybeans and corn. Our calculations show that increased corn ethanol production during the boom production year 2006/2007 explains approximately 27% of the experienced corn price rise.