The paper has methodological inconsistencies, particularly in the justification of the MMQR approach without comparison to alternative models. The treatment of human capital’s impact on pollution is oversimplified, lacking consideration of education’s role in environmental awareness. Additionally, the conclusions overstate the findings without adequately addressing limitations, which may affect the paper’s reliability. I recommend that the authors thoroughly address these issues to strengthen the study’s methodological robustness, incorporate a more nuanced analysis of human capital’s role, and ensure greater clarity and reliability in its conclusions.
The use of the MMQR approach is interesting, but could the authors elaborate on how they addressed potential endogeneity issues?
Moreover, the findings suggest that human capital has a negative impact on environmental quality, which is counterintuitive. Could the authors provide more discussion on the potential mechanisms driving this result? For example, does increased industrialization associated with higher human capital offset any environmental benefits from technological advancements and green skills?