Did the main functional area planning promote green development in China?

Issued in 2011, MFAP was China's first national plan to exploit its territorial space and support its transition to sustainable development, yet whether MFAP has actually translated into green development remains uncertain. To address that, we collected data for 270 cities in China and investigated MFAP's impact on their green technological progress and air pollutant emissions, by using a difference-in-difference (DID) analysis. Our results showed that MFAP was able to enhance regional green technological progress in Optimized development zones (ODZ), but not so in Key development zones (KDZ). Besides, investment in science and technology in addition to a changed land use pattern are two mechanisms by which MFAP could promote green technological progress. However, our results also revealed that, unlike for SO₂, MFAP did little to reduce the emissions of other common air pollutants, namely PM2.5 and O₃, especially in KDZ. Our findings suggest China's government should pay more attention to green economic development in KDZ and other potential problems there (e.g., life quality and welfare of rural residents and migrant workers) when pursuing its ambitious green transformation. In particular, policymakers should prioritize economic incentives in KDZ (e.g., more funding to spur innovation and tax relief for green industries) and integrate MFAP with stricter pollution controls to pursue holistic green development. The theoretical contributions of this study lie in first drawing an analogy with green policy instruments to show that spatial planning can also contribute to green technological progress and pollution control, and then in further analyzing the underlying mechanisms in terms of scale, composition, and technique effects. Its practical contributions lie in demonstrating the limitations of MFAP for mitigating air pollution in China, thus underscoring the need for crafting region-specific policies.