There has been an increase in the number of journal articles that are co-authored by researchers who claim to have made equal contributions. This growth has sparked discussions in the literature, especially within medical journals. To extend the debate beyond medical disciplines and support journal editors in forming an opinion, the current review collates and explores published viewpoints about so-called Equal Co-authorship (EC) practices. The Web of Science core database was used to identify publications that mention and discuss EC. Within the limited number of publications that were found on the Web of Science database, the most-cited item was used to trace other papers that discuss EC. In total, 39 papers (including articles and editorials) met the inclusion criteria. This review identifies four main themes within the sample including the growth of EC, challenges of attributing EC, guidelines and policies about EC and gender issues in the attribution of EC. Based on the survey and analysis of publications that discuss EC, this review provides recommendations regarding journal policy statements, and EC indicators. Those recommendations include: (1) journal policies should address EC; and (2) use should be made of available functionalities (CRediT, for example) to capture and indicate equal contributions.
Keywords: Authorship attribution; Equal co-authorship; Equal contribution; Recognition; Scientific authorship.