The relationship between the number of authors of a publication, its citations and the impact factor of the publishing journal: Evidence from Italy

Empirical evidence shows that co-authored publications achieve higher visibility and impact. The aim of the current work is to test for the existence of a similar correlation for Italian publications. We also verify if such correlation differs: (i) by subject category and macro-area; (ii) by document type; (iii) over the course of time. The results confirm world-level evidence, showing a consistent and significant linear growth in the citability of a publication with number of co-authors, in almost all subject categories. The effects are more remarkable in the fields of Social Sciences and Art & Humanities than in the Sciences - a finding not so obvious scrutinizing previous studies. Moreover, our results partly disavow the positive association between number of authors and prestige of the journal, as measured by its impact factor. (C) 2015 Elsevier Ltd. All rights reserved.