Diversified food supply capacity and rural residents’ income in China: evidence from provincial panel data

Introduction Against the backdrop of sustainable food-system transformation and China’s policy emphasis on an “all-encompassing approach to food,” whether a region’s combined capacity to supply multiple major food categories translates into higher rural incomes remains underexplored at the macro level. Methods Using panel data for 31 provincial-level regions in China from 2008 to 2023, this study constructs an entropy-weighted composite index of diversified food supply capacity based on the per capita supply of seven major food categories and examines its association with rural residents’ real per capita disposable income using two-way fixed-effects models. We further use DEA to examine scale efficiency as a potential production-side mechanism and employ the one-period lag of Food as an instrument in two-stage least squares (2SLS) estimation to address potential endogeneity concerns. Results The results show a significant positive association between diversified food supply capacity and rural residents’ income. This finding is generally robust to alternative sample periods, estimation methods, and measures of the core explanatory variable. Mechanism analysis shows that Food is significantly positively associated with scale efficiency. When Food and ATP are jointly included in the income equation, the ATP coefficient is positive and Food remains significantly positively associated with income. Discussion These findings suggest that diversified food supply capacity is positively associated with rural residents’ income and that scale efficiency may represent a potential production-side mechanism underlying this relationship. Because provincial panel data are unlikely to satisfy the stringent identification assumptions required for causal mediation analysis, the mechanism results should be interpreted as mechanism-related evidence rather than precise estimates of causal mediation effects.