Ben Hssain Lhoucine, Agouram Jamal, Lakhnati Ghizlane
LISAD, ENSA, Ibn Zohr University, Agadir, Morocco.
Sci Afr. 2022 Sep;17:e01321. doi: 10.1016/j.sciaf.2022.e01321. Epub 2022 Aug 13.
In this paper, we make an original contribution by identifying the impact of COVID-19 on Moroccan sectoral stocks indices. For this purpose, we collected data of 22 sectors from the Casablanca stock exchange from January 2017 to December 2021 and investigated two regres- sion models that included a dummy variable representing the onset of COVID-19. In addition, we examined performance measures (Sharp ratio and Treynor ratio) and risk measures (CVaR and Beta) of each individual sector before and during COVID-19. Furthermore, a GARCH model is applied to show conditional variance, aiming to emphasize the volatility of the selected stocks indices overall the chosen period. The results allowed us to divide sectors into two samples: the first one, referred to as sample 1, that was negatively impacted, and the second one, referred to as sample 2, that benefited from the pandemic of COVID-19. Further, conditional variance revealed that COVID-19 boosted, significantly but for a short period, the volatility of all sectors, even though the magnitude of the effect on volatility varies by sample and also by sector. Overall, we see COVID-19 as a crisis for some sectors and an opportunity for a new business transformation, as it is a period that results in significant improvement for some specific sectors. Furthermore, our results reflect the behavior of the sectors of an African emerging market during the COVID-19 outbreak, which is relevant for the formulation of strategies to ensure financial sustainability during future sanitary crises of this magnitude, for this type of economy.
在本文中,我们通过确定新冠疫情对摩洛哥各行业股票指数的影响做出了原创性贡献。为此,我们收集了2017年1月至2021年12月卡萨布兰卡证券交易所22个行业的数据,并研究了两个回归模型,其中包括一个代表新冠疫情爆发的虚拟变量。此外,我们还考察了新冠疫情之前和期间各行业的绩效指标(夏普比率和特雷诺比率)以及风险指标(条件风险价值和贝塔系数)。此外,应用广义自回归条件异方差(GARCH)模型来显示条件方差,旨在强调所选股票指数在整个选定期间的波动性。结果使我们能够将各行业分为两个样本:第一个样本称为样本1,受到负面影响;第二个样本称为样本2,受益于新冠疫情。此外,条件方差表明,新冠疫情显著但在短期内提高了所有行业的波动性,尽管对波动性的影响程度因样本和行业而异。总体而言,我们将新冠疫情视为一些行业的危机和新业务转型的机遇,因为这一时期会使一些特定行业得到显著改善。此外,我们的结果反映了新冠疫情爆发期间一个非洲新兴市场各行业的表现,这对于为这类经济体制定在未来如此规模的卫生危机期间确保金融可持续性的战略具有参考价值。