Results of the benchmark regression analysis.

Based on microdata of A-share listed companies in Shanghai and Shenzhen from 2009 to 2022 as research samples, this paper takes the implementation of Free Trade Zones policy as the starting point and using the difference in differences method to analyze the impact of the establishment of Free Trade Zones on the internationalization level of enterprises. The empirical results indicate that (1) Free Trade Zones policysignificantly improved enterprises’ internationalization level, and the conclusion still holds after a series of endogeneity and robustness tests. (2) Mechanism analysis showedthat digital transformation, resource allocation efficiency, and green innovation are intermediary variables affecting enterprises’ internationalization levels in Free Trade Zones. The establishment of Free Trade Zones can promote digital transformation, resource allocation efficiency, and green innovation of enterprises, thereby enhancing their internationalization level. (3) Heterogeneity analysis found that establishing free trade experiments has a more significant effect on improving the internationalization level of enterprises in low city levels, large-sized companies, capital-intensive and technology-intensive companies, businesses with executives who have overseas experience, and high-tech companies (4) Further research has found that the establishment of Free Trade Zones also has a positive spatial spillover effect on enterprises in surrounding cities. The above conclusion enriched and expanded the research on the impact of the establishment of Free Trade Zones on the internationalization level of enterprises and has important practical significance for enhancing the competitiveness of enterprises.本文以2009-2022年沪深A股上市公司微观数据为研究样本，以自由贸易试验区（Free Trade Zone, FTZ）政策实施为切入点，运用双重差分法（Difference-in-Differences, DID）分析自由贸易试验区设立对企业国际化水平的影响。实证结果表明：(1) 自由贸易试验区政策显著提升了企业国际化水平，且经过一系列内生性与稳健性检验后，该结论依然成立；(2) 机制分析显示，数字化转型、资源配置效率与绿色创新是自由贸易试验区影响企业国际化水平的中介变量，自由贸易试验区的设立能够推动企业开展数字化转型、提升资源配置效率与绿色创新能力，进而增强其国际化水平；(3) 异质性分析发现，设立自由贸易试验区对低行政层级城市企业、大型企业、资本密集型与技术密集型企业、拥有海外经历高管的企业以及高新技术企业的国际化水平提升作用更为显著；(4) 进一步研究表明，自由贸易试验区的设立对周边城市企业亦存在正向空间溢出效应。上述研究结论丰富并拓展了自由贸易试验区设立对企业国际化水平影响的相关研究，对于提升企业竞争力具有重要的现实意义。