Academic collaboration rates and citation associations vary substantially between countries and fields

Research collaboration is promoted by governments and research funders, but if the relative prevalence and merits of collaboration vary internationally then different national and disciplinary strategies may be needed to promote it. This study compares the team size and field normalized citation impact of research across all 27 Scopus broad fields in the 10 countries with the most journal articles indexed in Scopus 2008–2012. The results show that team size varies substantially by discipline and country, with Japan (4.2) having two‐thirds more authors per article than the United Kingdom (2.5). Solo authorship is rare in China (4%) but common in the United Kingdom (27%). While increasing team size associates with higher citation impact in almost all countries and fields, this association is much weaker in China than elsewhere. There are also field differences in the association between citation impact and collaboration. For example, larger team sizes in the Business, Management & Accounting category do not seem to associate with greater research impact, and for China and India, solo authorship associates with higher citation impact in this field. Overall, there are substantial international and field differences in the extent to which researchers collaborate and the extent to which collaboration associates with higher citation impact.