Abstract: National-level development zones are the backbone to promote economic growth, upgrade industrial structure and attract foreign investment. They are also the main battlefield to promote China's high-quality economic development. Therefore, both the central government and local governments are motivated to promote local economic development by establishing (applying for) national-level development zones. However, due to the involution tendency typical of the development zone's own development model, is the policy effect of establishing a national-level development zone as usual or weakening? Using the data of 271 prefecture level cities and taking the National-level High-tech Development Zones (NHDZ) as an example, this paper uses the synthetic control method to compare the policy effects of the establishment of NHDZ in 2010 and 2012. It is found that the establishment of NHDZ are still effective policies to promote local economic development, but (1) in terms of driving economic growth, compared with the establishment in 2010, the NHDZ established in 2012 have weakened their role in driving local GDP growth. 2017 alone saw an average decrease of RMB154 million; (2) In terms of driving the transformation of growth mode, the role of NHDZ established in 2012 decreased by an average of 0.33. It can be seen that the policy effect of the establishment has been weakened, which indirectly proves that there is a involution tendency in the NHDZ. Therefore, in the new development stage, governments at all levels should lower their expectations for the policy effects of the establishment of the NHDZ, focus their policies on the establishment of involution avoidance mechanism in the NHDZ, promote the transformation and upgrading of the NHDZ and achieve constructive growth.

Key words: development zones, policy effect, involution, synthetic control method, PSM-DID