Revisiting the environmental kuznets curve hypothesis: evidence from the ASEAN-5 countries with structural breaks

This paper tests if the Environmental Kuznets Curve (EKC) hypothesis exists for ASEAN-5 countries in an annual sample data that covers 1971–2013, by utilizing Auto Regressive Distributed Lag (ARDL) methodology. The empirical findings give support for the EKC hypothesis for Thailand only, after considering the structural breaks. Furthermore, the paper tests the EKC hypothesis for a panel data of the ASEAN-5 by adopting the Pooled Mean Group (PMG) methodology. The results show that the long-run estimates provide no evidence for the EKC hypothesis. Finally, the paper examines the causality between the CO₂ emissions and GDP. For individual countries, bidirectional causality was found in the case of Thailand and Malaysia, plus unidirectional causality running from GDP and squared GDP to CO₂ emissions was found for Indonesia, but a unidirectional causality running from CO₂ emissions to GDP and squared GDP was found for the Philippines, however, no causality effect was found for Singapore. Furthermore, the pairwise Dumitrescu and Hurlin Panel Causality test show a bidirectional effect between CO₂ emissions and both GDP in addition to squared GDP.