Examining the Effects of Economic Policy Uncertainty and R&D Expenditure on Green Innovation in the Presence of Geopolitical Risk in the United States: A Wavelet Cross‐Quantile Approach

Escalating geopolitical tensions and rising global uncertainties pose significant challenges to the US green innovation landscape, undermining the stability of clean energy investments and technology supply chains. While earlier research has examined the effects of economic uncertainty and market volatility on traditional energy sectors, little empirical work has investigated how geopolitical risk, economic policy uncertainty, R&D expenditure, trade openness and oil price fluctuations jointly shape green innovation. Using quarterly data from 1990 M01 to 2024 M12, this study employs a scale‐ and quantile‐sensitive wavelet cross‐quantile regression (WCQR) approach to capture the asymmetric and time‐varying relationships among these factors across different quantiles and time horizons. The results show that elevated geopolitical risk and policy uncertainty tend to constrain green innovation, particularly at higher quantiles, while persistent R&D investment and well‐managed trade openness enhance resilience and technological progress. These findings underscore the importance of stable policy frameworks, targeted R&D support and diversified supply chains to fortify the US green innovation ecosystem in an increasingly volatile global context.