While free-access and bronze Open Access articles from traditional publishers have been predominant in the Open Access market a decade ago and, according to some estimates, may continue to be more prevalent than other Open Access types, in recent years the number of articles published in Gold Open Access has exhibited consistent growth as Green, hybrid and other Open Access stagnated or declined, which can be due to its straightforward licensing terms.
A Blog Article by Pablo Markin.
In their recently published article, available as a preprint from August 2, 2017, and as a peer-reviewed publication from February 13, 2018, Heather Piwowar et al. have highlighted, on the basis of their empirical data, that, though estimates can vary depending on a database and sampling error, the share of free or Open Access articles of all articles available can vary from 28% to 45% for entire and yearly archives respectively, such as for 2015. For those who use services such as Unpaywall, which likely favors Open Access publications, the share of effectively Open Access articles in the underlying database can reach as high as 47%. Piwowar et al.’s study has also found that Open Access articles have 18% higher visibility, in terms of citations, than their non-Open Access counterparts.
Among the more interesting findings of this study, already extensively discussed in preprint form, is the stable and lightly improving citation performance of hybrid Open Access and closed-access articles between 2009 and 2015, with some citation level fluctuations in Green Open Access statistics in the same period. The volatile and recently relatively rising yearly average citation levels of bronze Open Access articles may need to be interpreted in the larger context of the growth dynamics that different Open Access sectors have experienced in this period. These findings may also be affected by the methodology that Piwowar et al. have applied to their data samples. According to their working definitions, Gold Open Access effectively refers to scholarly articles appearing in Open Access journals indexed by the Directory of Open Access Journals, Green Open Access comprises articles published in toll-based journals the archives or preprints of which are accessible from either institutional repositories or publisher servers in Open Access, hybrid Open Access includes articles published at subscription-based journals but freely accessible via one of Open Access licenses, bronze Open Access refers to unlicensed papers made free to read by their journal publishers and closed Open Access represents a catch-all category for toll-access publications at non-Open Access journals.
According to Unpaywall data (and corresponding CrossRef figures), these distinctions could be behind the steady decline in the market share, despite fluctuations, of both bronze Open Access from 26% (18%) in 2004 to 12% (16%) in 2016 and closed-access articles that accounted for 57% (71%) in 2004 all articles but for 40% (55%) in 2015 before rising to 50% (59%) in 2016. In contrast, in the same period, Green Open Access has declined from 9% (6%) in 2004 to 7% (4%) in 2016, despite moderate growth between these years, whereas Gold Open Access has been on a spectacular expansion course from 5% (2%) in 2004 to 19% (11%) in 2016. Likewise, hybrid Open Access grew significantly from 3% (3%) in 2004 to 11% (9%) in 2016.
These trends show that, through their licensing terms that consistently enable authors, readers and institutions to access and share publication contents, Gold and hybrid Open Access have expanded significantly their market shares in the publishing market in recent years.
By Pablo Markin
Featured Image Credits: Access (no access) Credit card sign, London, UK, April 21, 2010 | © Courtesy of Sludge G/Flickr.