Plan S Assessed: New ISI Global Research Report Offers Data-Driven Analysis of Open Access Initiative

When Plan S was announced in September of 2018, the call to sharply accelerate the spread of open access (OA) publishing stirred immediate discussion. The plan, an initiative of “cOAlition S,” a consortium of the European Research Council and national research agencies and funders, stipulates that researchers who benefit from state-funded projects and institutions must publish in open repositories or in journals in which all papers are publicly accessible.

While winning support from several European university associations and research councils, Plan S has also engendered resistance. Publishers, for example – large and small, including those representing learned societies – have expressed reservations, as have other observers concerned about how implementation of Plan S will have unintended consequences. The economic details of adopting Plan S have also provoked discussion – notably, the effect on authors in emerging economies, as well as unfunded researchers in the G20 nations, and how they or their institutions will deal with the Article Publishing Charges (APCs) required for some forms of OA publishing.

To the swirl of opinion and conjecture regarding Plan S, the Institute for Scientific Information (ISI), an arm of the Web of Science Group, brings the second of its Global Research Reports, wielding hard data from the Web of Science to assess the ramifications of the OA initiative.


The report, “The Plan S footprint: Implications for the scholarly publishing landscape,” examines recent patterns of publications funded by Plan S supporters, exploring potential impacts on funders, countries, publishers, and journals, not to mention specific areas of research.”


To ascertain as closely as possible the footprint of research underwritten by supporters of Plan S, the report’s authors examined a selection of papers (that is, articles and reviews) indexed in the Web of Science during 2017. Because Web of Science indexing captures all funding agencies acknowledged in a given paper, the analysis determined that papers with at least one Plan S-supporting funder constituted roughly 6% of 2017’s research output. (Because some authors fail to acknowledge funding sources, or the information may be missed due to obscure institutional name variants, this 6% figure represents a minimum estimate of funding by supporters of
Plan S.)

Given this sample of papers, the analysts were able to reach several conclusions about research funded by agencies association with Plan S – as well as to pose informed questions pertaining to how the wider adoption of the initiative might play out.

Among the report’s observations:

  • Based on 2017 citations, papers that acknowledge at least one Plan S funder are more highly cited, on average, than other papers – an effect that spans all research areas.
  • Some 90,000 papers funded by Plan S supporters but published in journals that are not fully compliant with the OA stipulations of Plan S might need to be “re-housed” if the journals do change to fully OA. This is just one of many difficult business decisions implied by Plan S.
  • Research areas challenged by Plan S are those low in OA compliance but relatively high in Plan S-funded papers; Mathematics is one such field. A further complication: Journals that are currently Plan S compliant are not evenly distributed, either across or within research areas.

In its examination of Web of Science data on Plan S-funded research, the report assesses other pertinent aspects, such as countries and regions and how the initiative will affect their percentages of OA output.

As the report makes plain, the adoption of Plan S is a sprawling matter, with myriad complex issues yet to be resolved among many parties.


Download the full Global Research Report on Plan S