Analysis of the Impact of Talent Introduction Policies on Urban Development Based on a Multi-Period Difference-in-Differences Model: A Case Study of the Yangtze River Delta Urban Agglomeration

Since the beginning of the new century, the process of globalization has deepened, prompting local governments to implement talent introduction policies to maintain sustainable urban development. Focusing on 27 cities in the Yangtze River Delta region, this study collects talent introduction policy texts and panel data from 2000 to 2010. Using Latent Dirichlet Allocation (LDA) for topic mining on text data, five main topics are identified: talent structure, industrial development, scientific and technological expenditures, financial development level, and innovation and entrepreneurship. To investigate the impact of talent introduction policies on these five topics and the overall level of urban economic development, this study uses the talent introduction policy as a quasi-natural experiment. Empirical analysis is conducted with a multi-period difference-in-differences (DID) model and double machine learning to explore the intrinsic mechanisms by which these policies empower urban economic development. The results reveal that: (1) Talent introduction policies have significantly promoted urban economic development, and this conclusion remains robust after a series of tests; (2) These policies indirectly boost urban economic development by enhancing financial development efficiency and increasing educational expenditure; (3) The economic growth-promoting effects of talent introduction policies are more evident in provincial capitals or municipalities, eastern cities, and cities with "211 Project" universities; (4) Talent introduction policies positively impact scientific and technological expenditures and innovation and entrepreneurship, negatively impact industrial structure, and have no significant effect on talent structure and financial development level. This study confirms the necessity of talent introduction policies since the beginning of the new century and provides recommendations for their continued implementation.