Supplementary file 1_Social service accessibility and Green Agricultural Development Intensity as pathways to Rural Elderly Welfare: panel evidence from China’s underserved regions.pdf

Three province-year cells are missing because Tibet and Hainan entered the relevant statistical series after 2013, and a further 29 cells were dropped through listwise deletion of province-years with incomplete sub-indicators. The data was collected from the China Statistical Yearbooks, CNNIC internet reports, and the China Health and Retirement Longitudinal Study. The estimation results were based on two-way fixed-effects regression with interaction terms, and a bootstrap mediation analysis with 5,000 replications.

The results were also checked for robustness through IV-2SLS estimation, winsorization, alternative specification for the dependent variable, excluding municipalities, and dynamic panel (system-GMM) estimation.</p>Results<p>SSA exerted a significant positive effect on REW (β = 0.27, p < 0.05), as did GADI (β = 0.18, p < 0.10). The SSA × GADI interaction was significant and positive (β = 0.14, p < 0.05), implying that the combined effect exceeds the additive effect of individual components.

Livelihood resilience partially mediated both the SSA–REW pathway (indirect effect = 0.09, 95% CI [0.03, 0.16]) and the GADI–REW pathway (indirect effect = 0.06, 95% CI [0.01, 0.12]). Contrary to expectations, DDI failed to significantly moderate the relationship between GADI and REW (β = −0.023, p = 0.412).</p>Conclusion<p>Coordinating social services with green agriculture was associated with wellbeing gains modestly but significantly greater than the sum of the two policy streams implemented in isolation.

The synergy premium was estimated at 6% over the additive prediction (approximately 1–11% based on the 95% CI of the interaction coefficient), a pattern consistent with partial transmission through livelihood resilience. Interventions in the underserved rural areas should focus on integrated packages consisting of improved access to healthcare services and subsidies in green agriculture, rather than the two policy streams in isolation.</p>