Does Open Access Really Increase Impact? A Large-Scale Randomized Analysis

Authors : Abdelghani Maddi, David Sapinho

The Open Access Citation Advantage (OACA) has been a major topic of discussion in the literature over the past twenty years. In this paper, we propose a method to constitute a control group to isolate the OACA effect. Thus, we compared citation impact (MNCS) of 2,458,378 publications in fully OA journals to that (weighted MNCS) of a control group of non-OA publications (#10,310,842).

Similarly, we did the same exercise for OA publications in hybrid journals (#1,024,430) and their control group (#11,533,001), over the period 2010-2020. The results showed that there is no OACA for publications in fully OA journals, and that there is rather a disadvantage. Conversely, the OACA seems to be a reality in hybrid journals, suggesting that a better accessibility tends to improve the impact of publications.

The lack of OACA for publications in fully OA journals is to be expected, as a great proportion of OA journals are newly created and less attractive to high-impact senior researchers. Another striking result of this paper is the fall of the OACA from 2016.

The citation advantage fell from 70% to 9% between 2016 and 2020 (for publications in hybrid journals). We wonder if this fall is linked to the increase in the notoriety of pirate sites (eg Sci-Hub) from 2016.

In other words, the democratization of pirate sites instantly cancels the positive effect of OA publication insofar as the question of access to scientific content no longer arises.


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

Authors : Pablo Dorta-González, Yolanda Santana-Jiménez

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 versus non-OA articles published in the same non-OA journals.

However, one problem with many studies is that they are small -restricted to a 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 paper, 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 paper 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.