The Impact of Financial Inclusion on Economic Growth: A Nonlinear Approach Considering the Human Development Index as a Mediator

This study examines the relationship between financial inclusion (IFI), human development (HDI), and economic growth (GDP) across 77 countries from 2004 to 2023. Using panel data regressions with fixed effects, we first confirm that IFI has a positive and significant impact on GDP, while also strongly influencing HDI. However, mediation analysis reveals that HDI does not significantly transmit the effects of FI to GDP, indicating that the impact of FI primarily operates through direct channels in the short term. To capture nonlinearities, we employ Panel Threshold Regression (PTR), which reveals the existence of an IFI threshold beyond which its contribution to growth becomes more pronounced. Furthermore, we combine causal machine learning methods with SHAP (Shapley Additive Explanations) and ALE (Accumulated Local Effects) to explore heterogeneity and enhance interpretability. This integrated framework not only validates earlier findings but also extends the explanatory power of the analysis, providing deeper insights into when and how FI fosters growth. The results imply that while FI is an important driver of economic expansion, its potential indirect benefits through human development require complementary investments in education, healthcare, and social protection.