Testing the nexus between renewable energy consumption and environmental quality in Nigeria: The role of broad-based financial development

This study investigates the nexus between renewable energy consumption and environmental quality in Nigeria, accounting for the role of financial development, and re-examines the validity of the environmental Kuznet curve (EKC) hypothesis for Nigeria covering the period 1990 to 2016. To cover financial development more adequately, the current study uses the broad-based financial development index constructed by the International Monetary Fund. The study employs second generation econometric approaches of Lee and Strazicich, and Bayer and Hanck combined cointegration tests to check for stationarity and cointegration among the variables, and then applies autoregressive distributed lag (ARDL) and vector error correction model (VECM) Granger causality tests to explore the effect and causal relationship respectively. The results divulge that renewable energy consumption improves environmental quality, while financial development hurts the environment. Further, the results validate an inverted U-shaped association between economic growth and environmental degradation in Nigeria. The VECM Granger causality results indicate a long-run effect of the independent variables on CO2 emission, while the short-run causality reveals a mixture of unidirectional and bidirectional causality among the variables. This study therefore recommends that policy makers consider the important roles of renewable energy and financial development in reforming energy policies to achieve environmental sustainability.