Pollution haven hypothesis (PHH) has been investigated extensively in the existing literature due to global environmental issues such as global warming and climate change. However, there is still no consensus on whether this hypothesis is valid. Therefore, the aim of this study is to examine the validity of the PHH in ASEAN-5 countries (Indonesia, Malaysia, Philippines, Singapore, and Thailand) covering the period of 1981-2014. It is utilized the up-to-date panel data techniques taking cross-sectional dependence and slope heterogeneity into account to test the relationship. According to the results of CCEMG and AMG estimators, the validity of the PHH is confirmed in ASEAN-5 countries. The increase in foreign direct investments (FDI) increases environmental degradation in these countries. Our additional findings show that the environmental Kuznets curve (EKC) hypothesis (EKC) is also valid in these countries. There is an inverted U shape between economic growth and CO2 emissions. In addition, energy consumption exacerbates CO2 emissions.
Addressing the challenges posed by pollutants is necessary to achieve Sustainable Development Goal 13, which involves climate change mitigation and enhancement of environmental quality. The convergence analysis of a pollutant provides information that can be useful to how to handle that pollutant across countries or regions, and previous studies mainly focused on carbon emission. However, the second most significant greenhouse gas, methane emission, was mostly ignored. The primary objective of this research is to investigate whether stochastic convergence of methane emissions is valid in 37 OECD (Organisation for Economic Co-operation and Development) countries using a dataset of more than two centuries. The results obtained by using a set of traditional unit root tests and a newly proposed wavelet unit root test with a Fourier function provide overwhelming evidence for these countries' divergence of methane emissions. The policy implications resulting from the empirical findings for environmental management are discussed in the relevant sections of the paper.
Despite being directly related to anthropogenic consumption and production, researchers have paid less attention to understanding the dynamics of non-methane volatile organic compounds. The primary objective of this research is to investigate the persistence of potential shocks to non-methane volatile organic compounds in 20 developed from 1820 to 2019 performing traditional unit root approaches and a newly developed Fourier quantile unit root test. Great portion of the empirical results obtained by traditional unit root tests reveal that the sectoral non-methane volatile organic compounds follow a non-stationary process, while the Fourier quantile unit root test indicate quite different results. The Fourier quantile test shows that non-methane volatile organic compounds are stationary in the United Kingdom, Ireland, Germany, France and Austria. In the other 15 countries, government interventions to reduce non-methane volatile organic compounds can have lasting effects and success. The inferences and policy outcomes of the empirical results are discussed in the main body of the paper.