Adekoya Oluwasegun B, Oliyide Johnson A
Department of Economics, Federal University of Agriculture, Abeokuta, Nigeria.
Resour Policy. 2021 Mar;70:101898. doi: 10.1016/j.resourpol.2020.101898. Epub 2020 Oct 20.
With many commodity and financial markets reportedly experiencing poor performances during this COVID-19 pandemic, this study intends to examine the effect of the pandemic on the connectedness among the markets. There are several reasons that suggest that apart from the pandemic affecting the performances of the markets, it can also be a driver of their connectedness, coming from the perspective of the global financial cycle channel. Therefore, we first employ the recently developed time-varying parameter vector autoregressions (TVP-VAR) technique to examine the volatility spillover among the commodity and financial assets. We find evidence of strong volatility across the markets, with gold and USD being net receivers of shocks, and others, net transmitters. With this evidence, we proceed to the evaluation of the influence of the COVID-19 pandemic on the connectedness across the markets using both the linear and non-linear (causality-in-quantiles) causality tests. The causality-in-quantiles test outperforms the linear Granger-causality test, and the results show significant causal impacts of the two measures of COVID-19 pandemic (infectious diseases-based equity market volatility and the growth rate of the U.S. COVID-19 reported cases) on the connectedness across the markets, especially at the lower and middle-level quantiles. Overall, these findings prove that the pandemic has been largely responsible for risks transmission across various commodity and financial markets. This is because it has significantly raised investors' and policy uncertainties and immensely altered global financial cycle which in turn results in global flows of capital, and movements in the prices of assets across different financial markets.
据报道,在此次新冠疫情期间,许多商品和金融市场表现不佳,本研究旨在考察疫情对市场间关联性的影响。有几个原因表明,除了疫情影响市场表现外,从全球金融周期渠道来看,它还可能是市场关联性的驱动因素。因此,我们首先采用最近发展起来的时变参数向量自回归(TVP-VAR)技术来考察商品和金融资产之间的波动溢出效应。我们发现各市场存在强烈的波动性,黄金和美元是冲击的净接受者,其他则是净传递者。基于这一证据,我们接着使用线性和非线性(分位数因果关系)因果检验来评估新冠疫情对市场间关联性的影响。分位数因果关系检验优于线性格兰杰因果关系检验,结果显示新冠疫情的两种度量(基于传染病的股票市场波动性和美国新冠确诊病例增长率)对市场间关联性有显著的因果影响,尤其是在较低和中等分位数水平。总体而言,这些发现证明疫情在很大程度上导致了各类商品和金融市场之间的风险传导。这是因为它显著增加了投资者和政策的不确定性,并极大地改变了全球金融周期,进而导致全球资本流动以及不同金融市场资产价格的变动。