Resumo do trabalho

This study investigates the evolution of the literature on capital structure under financial constraints, highlighting how institutional, regulatory, and macroeconomic factors shape corporate financing decisions. Growing attention to SMEs, financial frictions, and emerging risks calls for a systematic mapping of the field’s main thematic axes and recent shifts.

Despite the growing volume of publications on capital structure and financial constraints, there is a lack of systematic reviews that map the main research areas, identify thematic trends, and highlight emerging gaps. This study aims to fill that gap by organizing the literature into thematic clusters and analyzing recent shifts in focus, especially regarding SMEs, regulatory risk, and institutional diversity.

The literature on capital structure has evolved to incorporate financial constraints as a central element in corporate finance decisions. Key contributions emphasize how macroeconomic shocks, institutional quality, and organizational characteristics influence firms’ financing behavior. The concept of financial constraints is treated as multidimensional, involving external factors such as regulation and market cycles, as well as internal factors like governance and firm culture.

This study adopts a mixed-methods bibliometric approach combined with text mining techniques. A sample of 603 articles indexed in the Web of Science (1991–2024) was analyzed using TF-IDF vectorization, cosine similarity, K-means clustering, and Principal Component Analysis (PCA). Additional topic modeling (LDA) and chi-square tests were applied to evaluate thematic differences between highly cited and recent articles, enhancing the robustness of findings across clusters.

The findings reveal significant shifts in the literature on capital structure under financial constraints. Six thematic clusters were identified, highlighting trends from traditional topics—such as leverage and cash policy—to emerging issues like SMEs, regulatory risk, and climate finance. Statistical tests confirmed substantial differences between highly cited and recent articles, with the latter emphasizing institutional fragility, innovation, and sustainability. PCA and topic modeling validated the thematic diversification over time.

The study demonstrates that the literature on capital structure under financial constraints has undergone meaningful transformation, expanding beyond classical theories to include institutional, regulatory, and environmental dimensions. By integrating bibliometric analysis, text mining, and clustering techniques, the research maps the evolution of academic focus and highlights the growing relevance of SMEs and emerging risks. These findings offer a robust framework for future investigations and policy-oriented studies in corporate finance.

This study contributes methodologically by combining bibliometric techniques, text mining, and unsupervised learning to analyze a complex and evolving literature. Substantively, it uncovers the thematic diversification of research on financial constraints, emphasizing the emergence of new agendas such as SME finance, regulatory risk, and institutional fragility. The findings provide guidance for scholars, policymakers, and financial analysts seeking to navigate and shape future research in corporate finance.

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