Pathways for Sustainable Improvement of Ecological Efficiency: Insights from Digital Financial Inclusion in the Yangtze River Economic Belt

Whether and how digital financial inclusion (DFI) is associated with ecological efficiency (EE) is a critical issue for the sustainable development of the Yangtze River Economic Belt (YREB). Based on panel data from 2011 to 2023, this study measures EE using the PCA-Super SBM model, and employs panel fixed-effects models and mediation models to systematically examine the association, mechanisms, and regional patterns of DFI with EE in the YREB. The findings are as follows: (1) DFI and EE exhibit notable spatiotemporal co-evolution characteristics, with the DFI index increasing nearly 14-fold and the EE level rising by approximately 21.5% over the study period. (2) DFI shows a statistically significant positive association with EE improvement; this finding remains robust after various robustness checks. (3) The association between DFI and EE is partially mediated through four pathways: capital allocation optimization, green technological innovation, industrial structure upgrading, and environmental regulation strengthening, among which green technological innovation is the most prominent mediating pathway. (4) Numerically, the association strength varies across functional zones, being higher in the ecological barrier zone (EBZ) and the coordinated development zone (CDZ) than in the high-quality development zone (HQDZ); however, differences in coefficients across zones are not statistically significant and should be interpreted cautiously. Based on these findings, this study proposes policy recommendations including establishing a DFI-EE linkage platform, implementing differentiated functional-zone strategies, and strengthening cross-basin collaborative governance, thereby providing a reference for the green transformation of the YREB.