Research on the Driving Effect of Free Trade Zone Establishment on Urban Digital Economy Development—A Quasi-Natural Experiment Based on Panel Data from 274 Prefecture-Level Cities in China

设立自贸区是新时代推进改革开放的重要战略举措，本文使用2011~2022年我国274个地级市面板数据，采用多期双重差分法分析我国自贸试验区设立对数字经济发展水平的影响，发现自贸区设立能显著提升城市数字经济发展水平。机制检验表明，自贸区设立通过促进创新水平提升、推动营商环境优化和助力数字产业集聚三条路径发挥作用。此外，异质性检验表明，自贸区的设立对内陆地区、行政级别高的城市、经济发展水平高的城市的数字经济发展促进作用更为明显。本文的研究为完善自贸区政策设计、实施差异化发展政策以提升城市数字经济发展水平提供了理论依据。The establishment of Free Trade Zones (FTZs) is a crucial strategic initiative for advancing reform and opening-up in the new era. This study employs panel data from 274 prefecture-level cities in China, spanning 2011 to 2022, and utilizes a multi-period Difference-in-Differences (DID) approach to analyze the impact of FTZ establishment on the development level of the digital economy. The findings reveal that the establishment of FTZ significantly enhances urban digital economic development. Mechanism analysis demonstrates that FTZs drive this progress through three pathways: fostering innovation, optimizing the business environment, and facilitating digital industry clustering. Furthermore, heterogeneity tests indicate that FTZs exert a more pronounced promotional effect on digital economic development in inland regions, cities with higher administrative levels, and cities with more advanced economic development. This research provides academic evidence for refining FTZ policy design and implementing differentiated development strategies to elevate urban digital economic growth.