  Since Lawrence in 2001 proposed the open access (OA) citation advantage, the
potential benefit of OA in relation to the citation impact has been discussed
in depth. The methodology to test this postulate ranges from comparing the
impact factors of OA journals versus traditional ones, to comparing citations
of OA versus non-OA articles published in the same non-OA journals. However,
conclusions are not entirely consistent among fields, and two possible
explications have been suggested in those fields where a citation advantage has
been observed for OA: the early view and the selection bias postulates. In this
study, a longitudinal and multidisciplinary analysis of the gold OA citation
advantage is developed. All research articles in all journals for all subject
categories in the multidisciplinary database Web of Science are considered. A
total of 1,137,634 articles - 86,712 OA articles (7.6%) and 1,050,922 non-OA
articles (92.4%)- published in 2009 are analysed. The citation window
considered goes from 2009 to 2014, and data are aggregated for the 249
disciplines (subject categories). At journal level, we also study the evolution
of journal impact factors for OA and non-OA journals in those disciplines whose
OA prevalence is higher (top 36 subject categories). As the main conclusion,
there is no generalizable gold OA citation advantage, neither at article nor at
journal level.
