By employing time-frequency-domain frameworks, this study analyzes the spillover effects of news-based economic uncertainty caused by the pandemic on three renewable energy stock indices in the USA, Europe, and the world. The empirical results reveal that the total spillover from economic uncertainty to the three renewable energy stock returns was concentrated at a high frequency, whereas those to volatilities appeared at low frequencies. Utilizing a rolling-window method, we observed that the impact of uncertainty caused by COVID-19 on three renewable energy stock returns and volatilities is more significant than that resulting from the global financial crisis (GFC). During COVID-19, the majority of the spillover effects from economic uncertainty to returns and volatilities of the three indices focused on the long term.

中文翻译：

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COVID-19 造成的经济不确定性对可再生能源库存的影响。

通过采用时频域框架，本研究分析了由大流行引起的基于新闻的经济不确定性对美国、欧洲和世界三个可再生能源股票指数的溢出效应。实证结果表明，经济不确定性对三种可再生能源股票收益的总体溢出集中在高频，而对波动率的溢出则出现在低频。利用滚动窗口法，我们观察到 COVID-19 造成的不确定性对三种可再生能源股票收益和波动率的影响比全球金融危机 (GFC) 造成的影响更大。在 COVID-19 期间，经济不确定性对三个指数的回报和波动的溢出效应主要集中在长期。