Multinational teams and diseconomies of scale in collaborative research

Larger research teams are linked to decreasing impact, whereas contributions by international coauthors result in citation gains. Collaborative research has become the mainstay in knowledge production across many domains of science and is widely promoted as a means of cultivating research quality, enhanced resource utilization, and high impact. An accurate appraisal of the value of collaborative research efforts is necessary to inform current funding and research policies. We reveal contemporary trends in collaborative research spanning multiple subject fields, with a particular focus on interactions between nations. We also examined citation outcomes of research teams and confirmed the accumulative benefits of having additional authors and unique countries involved. However, when per capita citation rates were analyzed to disambiguate the effects of authors and countries, decreasing returns in citations were noted with increasing authors among large research teams. In contrast, an increasing number of unique countries had a persistent additive citation effect. We also assessed the placement of foreign authors relative to the first author in paper bylines of biomedical research articles, which demonstrated a significant citation advantage of having an international presence in the second-to-last author position, possibly occupied by foreign primary co-investigators. Our analyses highlight the evolution and functional impact of team dynamics in research and suggest empirical strategies to evaluate team science.