There has been a number of articles published about open access and its relationship with research impact. Although research continues into the multiple interdependent factors that contribute to research impact, the correlation between open access and citations has been demonstrated.
Hajjem et al. (2005) report that this applies accross quite different disciplines, not just hard sciences. Across biology, business, psychology and sociology, they report that citation counts are consistently higher for OA articles. This increase is between 25% and 250% higher than for articles with restricted access.
Antelman’s (2004) comparison of citation counts for articles in the disciplines of philosophy, political science, electrical and electronic engineering and mathematics showed a relative increase in citations for open access articles ranging from 45% in philosophy to 91% in mathematics.
Because open access articles are not restricted to subscribers, or licensed users, or those able to pay-per-view, the potential readership of articles reproduced in open access repositories is potentially far greater. For authors, large readership is a desirable commodity, and if that leads to increased citation counts, then archiving research papers in an institutional repository like e-publications@ bond is a worthwhile endeavour.
Links to these articles are for the versions in open access repositories.
2004) Do Open Access Articles Have a Greater Research Impact?. College & Research Libraries News 65(5):pp. 372-382. – http://eprints.rclis.org/archive/00002309/
2005) Open Access to Research Increases Citation Impact. Technical Report, Institut des sciences cognitives, Université du Québec à Montréal. – http://eprints.ecs.soton.ac.uk/11687/ (