Reserve currency and the volatility of clean energy stocks: The role of uncertainty
研究了美元（储备货币）价值变化如何影响清洁能源股票波动性，发现加入经济政策、汇率和黄金市场的不确定性后，美元升值会显著增加波动性，而不确定性起中介作用。
Clean energy firms are among the most risky firms to invest in. Hence, it is essential to have a clear understanding of the risk profile of clean energy stocks. The main purpose of this study is to examine how changes in the reserve currency (US dollar) value affect the volatility of clean energy stocks in the absence/presence of uncertainty information. To this end, the volatility of clean energy stocks is first obtained by considering uncertainty information in the exponential generalized autoregressive conditional heteroskedastic (EGARCH) volatility estimates. Then, using the autoregressive distributed lag (ARDL) model, this study investigates the effect of reserve currency (US dollar) value fluctuations on the volatility of clean energy stocks. Controlling for monetary conditions, financial stress, and business cycle fluctuations, the study finds that, in the absence of uncertainty information, the volatility of clean energy stocks is not influenced by US dollar fluctuations. However, an appreciation of the US dollar against major foreign currencies significantly increases the volatility of clean energy stocks when uncertainties about economic policy, exchange rate market, and gold market are included in the picture. We find that economic uncertainty mediates the link between reserve currency and the volatility of clean energy stocks. The results shed more light on the risk profile of clean energy stocks and suggest the need for predictable and stable policies to increase the attractiveness of clean energy stocks.