Reassessing the ecological effectiveness of ecological restoration programs: Evidence from a quasi-natural experiment in China

Globally, ecological restoration programs (ERPs) have emerged as vital tools for mitigating ecosystem degradation and preserving ecosystem services. Accurately assessing their effectiveness is essential to determining the success of these initiatives. However, the limitations inherent in traditional evaluation methods introduce uncertainty into these assessments. This study aims to reassess the ecological effectiveness of such programs through a counterfactual approach using quasi-natural experimental methods, thereby ensuring more accurate results and exploring potential impact pathways. We constructed a counterfactual scenario and employed a Difference-in-Differences (DID) model to evaluate the ecological benefits and mechanisms of China's National Key Ecological Functional Areas (NKEFAs). Additionally, we utilized a series of robustness tests for our findings. The results indicate: (1) NKEFAs have successfully restored ecological environments and produced positive ecological effects, although variations exist across different ecological function types and geographical regions. (2) Our analysis of transmission mechanisms suggests that optimization of national land use, upgrading of industrial structures, and labor force migration are critical pathways through which NKEFAs achieve ecological effectiveness. (3) Extended analysis reveals that NKEFAs not only have ecological spillover effects but also contribute to economic growth. Given that most global ERPs can implement counterfactual scenarios, the methodology used here offers a general framework that supports the achievement of the UN Sustainable Development Goals.