Department of Veterinary Medical Sciences, University of Naples Federico II, 80137 Naples, Italy.
Department of Managerial Studies and Quantitative Methods, University Parthenope Naples, 80133 Naples, Italy.
Int J Environ Res Public Health. 2020 Aug 12;17(16):5855. doi: 10.3390/ijerph17165855.
Many discussions following the 2007/08 food price crisis have revolved around the magnitude of the negative impacts that it may have had on food security worldwide. In South-Eastern Mediterranean countries (SEMC), food security is strongly interrelated with several key economic and political issues. Many of these countries are becoming increasingly import-dependent, particularly on cereals, which are the essential raw material for human and animal food and feed. Due to both their economic system structure and consumption, the SEMC are responsible for a third of world cereals imports, whereas they account for only 5% of the world population. Given the set of constraints and this dependence on global markets, SEMC will be probably more exposed to severe swings in agricultural commodity prices in the coming years. In this view, this study examines the dependence structure among global food grain markets and Morocco and provides flexible models for dependency and the conditional volatility GARCH. A copula-based GARCH model has been carried out to estimate the marginal distributions of Morocco and world cereals commodity price changes. The results revealed that the joint co-movement between agricultural commodity price changes around the world and in Morocco, are generally considerable and there exists asymmetric tail dependence.
许多关于 2007/08 年粮食价格危机的讨论都围绕着它可能对全球粮食安全产生的负面影响的程度展开。在地中海东南部国家(SEMC),粮食安全与几个关键的经济和政治问题密切相关。这些国家中有许多国家对进口的依赖程度越来越高,特别是对谷物的依赖,因为谷物是人类和动物食品和饲料的基本原料。由于经济体系结构和消费的原因,SEMC 占世界谷物进口的三分之一,而其仅占世界人口的 5%。鉴于一系列的限制因素和对全球市场的这种依赖,SEMC 在未来几年可能更容易受到农产品价格剧烈波动的影响。有鉴于此,本研究考察了全球粮食市场和摩洛哥之间的依赖结构,并提供了依赖关系和条件波动性 GARCH 的灵活模型。进行了基于 copula 的 GARCH 模型,以估计摩洛哥和世界谷物商品价格变化的边际分布。结果表明,全球和摩洛哥的农产品价格变化之间的联合共同运动通常是相当大的,并且存在不对称的尾部依赖。