Fractionalization of research impact reveals global trends in university collaboration

The importance of collaborations between research institutions in producing highly-cited publications is well documented in the scientometric literature. To avoid a double-counting of these publications at the institutional level, the fractional counting of article authorship is necessary. In this study, the effect of fractional counting on the number of publications from 1212 universities is examined at three levels of citation impact. Alongside an increase in publications over the decade from 2006–2009 to 2016–2019, increasing rates of inter-institutional collaboration are found to increase the division of citation impact being attributed to each collaborating university. This trend is strongly expressed by most major universities and suggests that the structure of research is evolving towards a highly networked model of production in which authorship, and therefore citation impact, is highly dispersed. The growing differences in the fractionalization of publications at different levels of citation impact suggests a divergence in the structure of science. The implications for university rankings in an environment in which research impact is broadly dispersed among many collaborating institutions are discussed.