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.

URL: https://hal.archives-ouvertes.fr/hal-03694666