Are successful co-authors more important than first authors for publishing academic journal articles?

Academic research often involves teams of experts, and it seems reasonable to believe that successful main authors or co-authors would tend to help produce better research. This article investigates an aspect of this across science with an indirect method: the extent to which the publishing record of an article’s authors associates with the citation impact of the publishing journal (as a proxy for the quality of the article). The data is based on author career publishing evidence for journal articles 2014–20 and the journals of articles published in 2017. At the Scopus broad field level, international correlations and country-specific regressions for five English-speaking nations (Australia, Ireland, New Zealand, UK and USA) suggest that first author citation impact is more important than co-author citation impact, but co-author productivity is more important than first author productivity. Moreover, author citation impact is more important than author productivity. There are disciplinary differences in the results, with first author productivity surprisingly tending to be a disadvantage in the physical sciences and life sciences, at least in the sense of associating with lower impact journals. The results are limited by the regressions only including domestic research and a lack of evidence-based cause-and-effect explanations. Nevertheless, the data suggests that impactful team members are more important than productive team members, and that whilst an impactful first author is a science-wide advantage, an experienced first author is often not.