Digital Inclusive Finance and Coordinated Eco-City Development: An XGBoost-SHAP Analysis

Eco-city (EC) development depends not only on environmental governance but also on the allocation of financial and technological resources. Digital inclusive finance (DIF) may be associated with green development through improved financial accessibility and resource allocation; however, its predictive relationship with coordinated EC development remains insufficiently characterized. Using panel data for 284 prefecture-level or higher-level cities in China from 2011 to 2023, this study constructs an EC coordinated evaluation system across four dimensions: low-carbon transition, environmental governance, ecological enhancement, and economic and social well-being. It then employs an XGBoost-SHAP framework to examine the relative predictive importance and nonlinear patterns associated with DIF and to compare these patterns across the four dimensions of eco-city development. The results show that coordinated EC development generally improved over the study period, while substantial spatial differences persisted and significant positive spatial autocorrelation was observed. Among the included features, DIF exhibits the largest mean absolute SHAP value in predicting coordinated EC development. Its SHAP contribution shifts nonlinearly from negative to positive relative to the prediction baseline, with a descriptive model-based zero-crossing around a DIF index value of 200 rather than a statistically estimated threshold. The predictive importance and nonlinear contribution patterns of DIF also vary substantially across dimensions, with greater relative importance for environmental governance and ecological enhancement than for low-carbon transition and economic and social well-being. These findings remain broadly robust under city-grouped holdout validation, an alternative nonlinear model, a two-way fixed-effects benchmark, and alternative subsystem-weighting schemes. The study provides a multidimensional perspective for understanding the predictive association between digital inclusive finance and coordinated eco-city development.