Revisiting the Existence of EKC Hypothesis under Different Degrees of Population Aging: Empirical Analysis of Panel Data from 140 Countries

Abstract

Population aging and environmental sustainability have become two hot topics in the world today. To clarify whether the Environmental Kuninets Curve (EKC) hypothesis between the economy and the environment is still valid in the context of population aging is the key to reveal the complexity of social-ecological systems in aging societies. So far, the impact of population aging on the environment has not been clear. To this end, an empirical analysis on the threshold panel model was conducted using panel data of 140 countries from 2000 to 2015. The global findings suggest that economic growth was the main reason for the increase in the ecological footprint at the beginning of aging. However, deepening aging weakened this association between economic and ecological footprints. For high-income countries, with the deepening of aging, the economic and ecological footprints were firstly negatively correlated, then positively correlated, and finally negatively correlated. In other words, the EKC hypothesis remained valid in high-income countries as aging deepened. In contrast, for the low- and middle-income group, the economic-environmental association was not affected by the degree of aging. This result sheds light on the variability of different income country groups in coping with the environmental impacts of aging. For the high-income group, policy makers should pay attention to the aging threshold in socio-ecological management. Only in this way can the development of aging and the ecological environment be reconciled to the greatest extent.

The relationship between economic growth and environmental degradation: could West African countries benefit from EKC hypothesis?

“…Generally, the findings of this study support He et al ( 2021 ), Ntarmah et al ( 2022 ), and Tachega et al ( 2021 ) who revealed mixed results in terms of EKC existence. Particularly, the results support Li and Li’s ( 2021 ) findings that established EKC in high-income countries but not LICs. The likeness of AMG and CCEMG shows that the results are reliable.…”

“…It is important to note that while these studies are consistent in their findings, they fail to explore the possible existence of the EKC hypothesis in their data. While GDP is expected to increase CO 2 at some point, further economic expansion may reduce CO 2 due to changes in lifestyle and the quest for improvement in the environment (Li and Li 2021 ). Thus, the EKC hypothesis cannot be ignored in current environmental studies.…”

How do energy consumption, globalization, and income inequality affect environmental quality across growth regimes?

“…It was determined that there are statistically significant threshold effects associated with both industrial structure and urbanization on the inverted U-shaped relationship between the EF and GDP. Li and Li ( 2021 ) concluded that EKC holds true in high-income countries when the degree of aging serves as a transition variable. Simionescu ( 2021 ) also provided support for the hypothesis by demonstrating an N-shaped relationship between CCE countries’ GHG emissions and GDP data.…”