Convergence of Per Capita CO₂ Emissions in EAGLE Economies: Evidence from the Fourier Quantile Unit Root Test
DOI:
https://doi.org/10.63556/tisej.2026.1879Keywords:
CO₂ Emissions, Convergence, Fourier Quantile Unit Root Test, EAGLE EconomiesAbstract
The aim of this research is to examine whether per capita CO₂ emissions among emerging economies stochastic converge in the context of EAGLE, namely Brazil, China, Egypt, India, Indonesia, Mexico, Russia, South Korea and Türkiye. In order to overcome the limitations of traditional unit root tests, the Fourier Quantile Unit Root Test, which takes into account structural breaks and nonlinearities, is used. This method allows a more detailed evaluation of the convergence behavior by examining the stationarity properties of the series at different quantiles. The originality of this research is that it makes an innovative contribution to the convergence analysis of per capita carbon emissions with its quantile-based and structural break-inclusive Fourier approach. Thus, it shows that environmental policies may have different effects depending on the country and distribution level, and guides policy makers in developing flexible and target-oriented strategies. The findings reveal a heterogeneous and quantile-dependent pattern of country-specific stochastic convergence. Stationarity is detected across all examined quantiles for China and South Korea. For the remaining economies, stationarity is observed only at particular quantiles: τ = 0.10, 0.30, 0.80, and 0.90 for Brazil; τ = 0.30–0.90 for Egypt; τ = 0.20–0.50 for India; τ = 0.30, 0.40, 0.60, 0.70, and 0.90 for Indonesia; τ = 0.30, 0.50, 0.80, and 0.90 for Mexico; and τ = 0.10, 0.30–0.70, and 0.90 for Türkiye. Russia exhibits limited evidence of stationarity, which is detected only at τ = 0.20 and 0.80. In addition, the Fourier Quantile Kolmogorov–Smirnov test provides distribution-wide evidence of stochastic convergence for China, Indonesia, and Türkiye. These results indicate country-specific mean reversion rather than direct convergence of emission levels across EAGLE economies.
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