Prevalence and citation advantage of gold open access in the subject areas of the Scopus database

The potential benefit of open access (OA) in relation to citation impact has been discussed in the literature in depth. The methodology used to test the OA citation advantage includes comparing OA vs. non-OA journal impact factors and citations of OA vs. non-OA articles published in the same non-OA journals. However, one problem with many studies is that they are small and restricted to one discipline or set of journals-. Moreover, conclusions are not entirely consistent among research areas, and 'early view' and 'selection bias' have been suggested as possible explications. In the present article, an analysis of gold OA from across all areas of research-the 27 subject areas of the Scopus database-is realized. As a novel contribution, this article takes a journal-level approach to assessing the OA citation advantage, whereas many others take a paper-level approach. Data were obtained from Scimago Lab, sorted using Scopus database, and tagged as OA/non-OA using the DOAJ list. Jointly with the OA citation advantage, the OA prevalence as well as the differences between access types (OA vs. non-OA) in production and referencing are tested. A total of 3,737 OA journals (16.8%) and 18,485 non-OA journals (83.2%) published in 2015 are considered. As the main conclusion, there is no generalizable gold OA citation advantage at journal level.