Faculty of Economics, National Economics University, Hanoi, Vietnam.
Environ Sci Pollut Res Int. 2024 Mar;31(12):17994-18009. doi: 10.1007/s11356-023-26033-1. Epub 2023 Mar 14.
The study explores inter-relations between the geopolitical risk index and renewable energy volatility index at frequency dimensions from April 4, 2019, to June 13, 2022, using novel multivariate wavelet analysis approaches, such as partial wavelet coherency and partial wavelet gain. Our method allows us to study these interlinkages at various time frequencies. We also consider the influences of uncertain events like the COVID-19 pandemic and Ukraine-Russia conflicts on their interconnectedness. The multiple coherencies between the geopolitical risk index and the green energy sector suggest four cycles in the low-frequency range (50-130 days) from March 2020 to October 2021 and from February 2022 to June 2022. The partial coherency between the geopolitical risk index and renewable energy volatility index suggests connectedness between renewable energy dynamics and geopolitical risks during the COVID-19 duration and the Russia-Ukraine conflict. The partial wavelet coherency of the volatility of green bonds and geopolitical risks suggests that alterations in green bonds caused alterations in geopolitical risks, and the association is negative from February 2021 to April 2021. Both indicators are in-phase with geopolitical risks pushing from February 2020 to April 2020 and from October 2021 to the end of the sample. The partial coherence between clean energy and geopolitical risk suggests geopolitical risks pushing anti-phase connectedness from September 2020 to September 2022. Our findings help policymakers design the most effective policies to lessen the vulnerabilities of these indicators and reduce the spread of risk or uncertainty across them by having insightful knowledge about the primary antecedents of the contagions among these indicators.
本研究利用新的多变量小波分析方法，如部分小波相干性和部分小波增益，在 2019 年 4 月 4 日至 2022 年 6 月 13 日的频率维度上探讨了地缘政治风险指数和可再生能源波动指数之间的相互关系。我们的方法允许我们在不同的时间频率上研究这些相互关系。我们还考虑了 COVID-19 大流行和俄乌冲突等不确定事件对它们相互联系的影响。地缘政治风险指数和绿色能源部门之间的多重相关性表明，从 2020 年 3 月到 2021 年 10 月和从 2022 年 2 月到 2022 年 6 月，低频范围内（50-130 天）存在四个周期。地缘政治风险指数和可再生能源波动性指数之间的部分相关性表明，在 COVID-19 期间和俄乌冲突期间，可再生能源动态与地缘政治风险之间存在联系。绿色债券和地缘政治风险的部分小波相干性表明，绿色债券的变化导致了地缘政治风险的变化，这种关联从 2021 年 2 月到 4 月是负面的。从 2020 年 2 月到 4 月和从 2021 年 10 月到样本结束，这两个指标都与地缘政治风险同相，推动地缘政治风险。绿色能源和地缘政治风险之间的部分相关性表明，地缘政治风险从 2020 年 9 月到 2022 年 9 月推动反相联系。我们的研究结果有助于政策制定者设计最有效的政策，以减轻这些指标的脆弱性，并通过深入了解这些指标之间传染的主要前兆，减少风险或不确定性在它们之间的传播。
