Naima . Sadaoui

espite the diversity of theoretical studies, natural resources’ moderating role between governance indicators and environmental quality remains a controversial issue. The purpose of this paper is therefore to clarify the nature of this role in the Middle East and North Africa (MENA) countries from 1996 to 2017 relying on the generalized method of moments system estimators.

This study examines the moderating ICT plays in shadow economy–environmental pollution nexus in Nigeria between 1984 and 2017. Further, the study also determines the threshold level of ICT that lessens shadow economy and abates environmental pollution. Results from the study show that shadow economy has a positive and significant effect on environmental pollution both in the short and long run, while ICT has a negative effect on environmental pollution. This reveals that shadow economy worsens environmental quality while ICT abates environmental pollution.

With the climate challenges and the depletion of fossil resources, the renewable energy option seems to be a wise choice; this renews the debate on the relationship between renewable energy sources consumption and economic growth. This study relies on a threshold effects regression model to explore and evaluate the non-linear relationship between the series in the United States during the period 1984Q1–2021Q3. Using the threshold detection method proposed by Hansen and Seo (2002), the results of this method show that the renewable energy sources consumption/GDP relationship is non-linear.