According to numerous studies based on the very exhaustive Open Citation Project, Open Access leads to a significant increase in the number of times a reference is cited (between 2.5 and 5 times than is the case for a paper article).
These figures are confirmed at the level of ORBi. A study carried out in September 2011 on the Scorpus v. ORBi database in effect shows that references deposited on ORBi are cited twice as many times. Hard to believe it is simply a matter of chance!
The study Self-Selected or Mandated, Open Access Increases Citation Impact for Higher Quality Research (Gargouri, Y., Hajjem, C., Lariviere, V., Gingras, Y., Brody, T., Carr, L. and Harnad, S., 2010) adds a fundamental qualitative element:
«The OA advantage is greater for the more citable articles, not because of a quality bias from authors self-selecting what to make OA, but because of a quality advantage, from users self-selecting what to use and cite, freed by OA from the constraints of selective accessibility to subscribers only (…).
In the online era, researchers' own "mandate" will no longer just be "publish-or-perish" but "self-archive to flourish" ».