The opening of high-speed rail (HSR) and the operation of enclave parks (EP) are both important cross-regional economic activities that play a pivotal role in promoting regional economic development. This study modifies the previous single-dimension research paradigm of the HSR effects and EP effects, focusing on the synergistic relationship between HSR and EP in the process of urban economic development. We design a staggered difference-in-differences (DID) model based on the realistic background of the synchronized development of HSR and EP in the Yangtze River Delta region to test the joint impact of HSR and EP on the urban economy, and its heterogeneous performance and mechanisms. The results indicate that the joint impact of HSR and EP on the urban economy is superior to their individual impacts, confirming the synergistic effect of the HSR and EP. In addition, the joint impact of HSR and EP on the urban economy is heterogeneous. The joint economic effects of the HSR and EP are stronger in the fly-out cities of enclave parks. Core and large-scale cities benefit more from the synergistic economic effects of HSR and EP. In terms of the sequence of intervention, the operation of the EP after the opening of HSR can better accelerate economic growth. Finally, we demonstrate that HSR and EP can promote economic development synergistically by alleviating urban resource misallocation and that market development has an important moderating effect on the synergistic effect of HSR and EP.

中文翻译：

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评估长三角地区高铁与飞地园区的联合经济效应

高铁开通和飞地园区运营都是重要的跨区域经济活动，对促进区域经济发展发挥着举足轻重的作用。本研究改变了以往高铁效应和环保效应的单一维度研究范式，重点研究高铁与环保在城市经济发展过程中的协同关系。基于长三角地区高铁与环保同步发展的现实背景，设计交错双重差分（DID）模型，检验高铁与环保对城市经济的共同影响及其异质表现。和机制。结果表明，高铁和环保对城市经济的共同影响优于其单独影响，证实了高铁和环保的协同效应。此外，高铁和环保对城市经济的共同影响是异质的。在飞地公园的飞行城市中，高铁和EP 的联合经济效应更强。核心城市和大型城市更多地受益于高铁和环保的协同经济效应。从干预顺序来看，高铁开通后运行EP能够更好地加速经济增长。最后，我们证明高铁和环保可以通过缓解城市资源错配来协同促进经济发展，而市场发展对高铁和环保的协同效应具有重要的调节作用。