The cognitive benefits of ecosystem improvement: Evidence from China's National Key Ecological Function Zones

Despite growing evidence of a strong correlation between ecosystem changes and human health, the direct impact of ecological improvements on cognitive function remains underexplored. This study examines the impact of China's National Key Ecological Function Zones (NKEFZs) policy on residents' cognitive function, employing a staggered Difference-in-Differences model. Using large-scale longitudinal survey data from 92,825 adults, our findings indicate that NKEFZs implementation is associated with significant improvements in cognitive outcomes, with cognitive scores increasing by 0.0291 standard deviations for vocabulary, 0.0703 for mathematical scores, and 0.0993 for overall cognitive function. Further analysis reveals that these effects are mediated by enhanced objective health status, reduced depression, and increased outdoor exercise frequency. Heterogeneity analysis suggests that the cognitive benefits of NKEFZs implementation vary across demographic groups, with older and lower-income individuals experiencing less pronounced effects. These findings emphasize the broader public health implications of ecosystem improvement.