Short abstract

We examine disparities in North-South medical collaborations using PLOS ONE metadata and a new TF-IDF-based method to quantify contributions. Accounting for authors’ output, impact, gender, age, and specialization, we document clear regional imbalances and misalignment between roles and authorships.

Long abstract

Global North-South disparities persist in science, yet our understanding of the mechanisms sustaining them remain limited. Focusing on North-South research partnerships, this study examines how the division of labor within medical research teams contributes to these disparities. We harvested article metadata from PLOS ONE alongside CRediT contributorship data, and then applied a new TF-IDF-based method to account for variation in the prevalence and distribution of contributor roles across authors. In linear probability models, adjusting for authors’ prior publication output and impact, gender, scientific age, medical specialization and TF-IDF adjusted contributor roles, we find that GS researchers are more likely to assume first authorships but have substantially lower representation in last and corresponding authorships compared to their GN team-mates. Subgroup analyses reveal that this regional disadvantage is most pronounced for researchers from Africa, Latin America, and Southeast Asia, while those from East and South Asia are underrepresented in all lead-authorship roles, including also first authorships. This pattern also holds across national income levels, with clear disparities observed between researchers from lower- and higher-income countries. We also find that while leadership roles generally increase the likelihood of assuming first-, last- or corresponding authorships, GS scientists with such roles remain less likely to obtain last authorships. These findings expose a consistent misalignment between contributions and authorship positions in North-South collaborations and highlight the need for experimental research to clarify the causal pathways through which these imbalances arise.