The Impact of China National Modern Agricultural Demonstration Zones on Green Total Factor Productivity in Grain Production

In this study, we construct a green total factor productivity (GTFP) index for grain production using a super-efficiency SBM model. Exploiting the quasi-natural experiment provided by the National Modern Agricultural Demonstration Zones (NMADZ) policy and employing county-level panel data from 309 Chinese counties over the period 2010–2022, we apply a double machine learning framework to examine the impact of NMADZ on grain GTFP and to explore the underlying transmission mechanisms. The results show that NMADZ significantly improves grain GTFP, and these findings remain robust after a series of tests. Technological innovation and institutional restructuring play crucial roles as mediating mechanisms in promoting grain GTFP. Heterogeneity analysis reveals that the enhancing effect of NMADZ is more pronounced for grain production in high-latitude regions, given its lower susceptibility to climate and disaster factors. For counties with a weak innovation foundation, adopting a strategy focused on acquiring patented technologies is more suitable in the short term. Furthermore, features of scale and intensification of production characterize the empowering effect of NMADZ.