Research on the impact of the major grain-producing areas policy on the coordination between grain supply security and low-carbon agricultural development

Balancing food security with low-carbon agricultural development has become a major challenge for sustainable agri-food systems in the era of climate change. This study examines whether the major grain producing areas policy promotes the coordination between grain supply security and low-carbon agricultural development of 13 major grain-producing areas in China in 2004 as an institutional shock. Using panel data from 30 provincial-level regions in China from 1998 to 2023, we construct a coupling coordination index based on the normalized grain output and agricultural carbon-emission efficiency, and estimate policy effects using a Difference-in-Differences approach. The results show that the major grain-producing areas policy significantly improves the coordination between grain supply security and low-carbon agricultural development. This finding remains robust after placebo tests, PSM-DID estimation, the exclusion of municipalities directly under the central government, an alternative dependent variable test based on per capita grain availability, and a province-specific linear trend specification. Mechanism analysis indicates the policy primarily operates through scale operation and agricultural mechanization. Heterogeneity analysis shows the policy effect is more pronounced in inland provinces than coastal provinces, is significant in the eastern and central regions, but not significant in the western regions. Overall, this study provides causal evidence that regionally targeted agricultural policies can generate synergies between grain supply security and low-carbon agricultural development. It also offers policy implications for optimizing support in major grain-producing areas and advancing climate-smart agricultural development.