摘要
Uncertainty can affect both macroeconomic indicators and the environment.Countries are implementing various energy policies to combat global warming,but these policies contain some uncertainties and contradictions.The environmental impact of uncertainties in energy policies is a research topic that has just begun to be investigated by researchers.This study examines the effects of energy policy uncertainty(ENERPU)on renewable energy R&D(RR&D),energy efficiency R&D(EER&D)and renewable energy consumption in the four countries with the highest RR&D expenditures(USA,Germany,Japan,and Spain).The study uses the novel multivariate quantile-on-quantile(M-QQR)approach from 2003m1 to 2022m9.The results of the study show:(i)The impact of ENERPU varies by quantile and country.(ii)ENERPU causes a decrease in renewable energy consumption and hinders RR&D expenditures.(iii)ENERPU increases EER&D.The Fourier quantile causality test confirms the robustness of the empirical results.Based on these findings,policymakers are recommended to minimize ENERPU and implement stable energy policies to develop the renewable energy sector and technologies.
