Cattle Stock and Enteric Methane Emissions in E7 Economies: Evidence from CS-ARDL, MMQR, and Wavelet Quantile Correlation

This study examines the relationship between cattle stock and enteric fermentation-derived methane (CH₄) emissions across E7 economies (Brazil, China, India, Indonesia, Mexico, Russia, and Türkiye) over the 2000–2022 period using panel data methods. The CS-ARDL estimator, which simultaneously addresses cross-sectional dependence and slope heterogeneity, places the short-run elasticity of cattle stock at 1.077 and the long-run elasticity at 1.154. These above-unity coefficients indicate that herd growth generates disproportionate emission increases in both the immediate and permanent dimensions. In the quantile analysis conducted via Machado and Santos Silva's (2019) MMQR approach, the lnCOW coefficient remains strong and positive across the full emission distribution while declining modestly from 1.263 at the lower quantile to 1.153 at the upper quantile. Wavelet Quantile Correlation (WQC) findings reveal high and stable correlations ranging from 0.723 to 0.879 across all D1, D2, and S2 frequency bands, confirming that the relationship is driven by a structural mechanism rather than short-run cyclical fluctuations. The findings underscore the urgency of policy instruments that directly target herd management, incorporate investment support for production efficiency transitions, and anchor these measures within national climate commitments in E7 countries.