The intellectual structure and thematic evolution of middle-income trap research: A bibliometric analysis (2009–2025)

Despite the rapid growth of scholarly and policy interest in the middle-income trap (MIT) since its formal introduction in 2007, the literature remains fragmented, with limited efforts to systematically map its intellectual structure or thematic evolution. This study presents the first comprehensive bibliometric analysis of MIT research, covering 385 publications indexed in the Web of Science (2009–2025). Using a triangulated methodology that integrates Bibexcel for performance metrics, VOSviewer for co-authorship and keyword network mapping, and SciMAT for longitudinal thematic evolution, the study identifies the core trajectories, knowledge clusters, and strategic shifts that have shaped the field over time. Results reveal a dynamic research domain increasingly grounded in themes such as structural transformation, innovation capacity, institutional reform, and human capital development, with strong regional concentration in Asia and Latin America. Thematic evolution analysis demonstrates both conceptual maturation and persistent fragmentation, as the core notion of the MIT remains under-theorized and variably defined. By exposing the field’s structural dynamics, dominant actors, and conceptual gaps, this study offers a critical roadmap for scholars, while providing policymakers with a consolidated view of the research frontiers most relevant to long-run growth and developmental upgrading.