Do renewable energy and geopolitical risk affect industrial productivity in Turkey: Evidence from Quantile on Quantile and causality in quantiles approach

This research examines the asymmetric relationship between renewable energy adoption, geopolitical risk, and industrial productivity in Turkey, a country with a dynamic geopolitical landscape and evolving energy structure. Using monthly data from January 2001 to September 2021, the study employs Quantile-on-Quantile Regression (QQR) and Granger Causality-in-Quantiles methods. Findings reveal that clean energy's effect on industrial productivity is nonlinear and varies across quantiles. At low quantiles (0.1–0.3), the impact is negative; at quantiles 0.2 and 0.4–0.5, it becomes positive, while at 0.6–0.7, it turns negative again and improves at 0.8. This pattern supports the pollution haven hypothesis, indicating that the influence of clean energy depends on the current productivity level. Regarding geopolitical risk, industrial productivity shows a negative response at low to mid quantiles (0.1–0.5) but turns positive in the 0.6–0.8 range. However, at extreme quantiles (0.90–0.95), the effect becomes strongly negative again, revealing vulnerability under high-risk conditions. The robustness of the results is confirmed by standard quantile regression, and Granger causality tests reveal bidirectional causal links between clean energy, geopolitical risk, and productivity. Overall, the study highlights the importance of clean energy transition and geopolitical stability for enhancing industrial resilience and environmental sustainability in Turkey.