This month we look at the types of licenses attached to open access publications. We examine the balance between more or less permissive licenses, and the patterns make for interesting reading.


Definitions matter when quantifying Open Access. Formal definitions of open access require that articles are both free of charge and of reuse restrictions. While Creative Commons licenses have become the de facto standard for open access publications, these licenses offer a range of permissions. Given that some funders insist on the most permissive license types, while more restricted licenses, such as those prohibiting commercial or derivative use, are also widespread, we thought a deeper look was warranted.

As part of our 2020 market sizing, we added a layer of analysis to our data which examines how prevalent different license types are. Additionally, working with OASPA on their annual members’ survey has yielded further insights into license usage.

License Usage

Licenses for reuse may be subject to different levels of restrictions. For our analysis, we define these as:

  • “Permissive” refers to articles published under CC BY (attribution only required) or CC0(no restriction). CC BY is typically the license required by major funders of OA, such as Plan S, Wellcome, HHMI, etc.
  • “Restricted” refers to articles published under other licenses that allow restricted reuse, such as CC BY-NC (non-commercial), CC BY-ND (no derivative), or publisher-specific licenses. Although not conforming to the strictest OA mandates, such licenses are widely used and are consistent with many OA requirements. Publishers sometimes charge lower APCs for these more restrictive licenses compared with their permissive counterparts.
  • Although its impact is minimal, we include the CC BY “ShareAlike” license in the Restricted category, as it effectively imposes restrictions on use of derived works.

The use of these license types in open access is shown in the following figure.

The chart splits these licenses between content in fully OA journals (in yellow), and the OA content in other journals (“hybrid” – in blue).

  • Overall, the Permissive licenses (CC0, CC BY – the paler colors) are most commonly used, outnumbering more restrictive ones by around 3:2.
  • Within fully OA journals, the ratio is nearer 2:1, compared with an even split in hybrid publications.

Variations by Discipline

Looking at our full data set, which allows for deeper analysis, breaking the data out by publisher and discipline shows that patterns of use vary. For example:

  • Larger publishers with mixed portfolios of fully OA and hybrid journals publish a greater proportion of their output in hybrid journals. They also publish a significantly greater proportion of their output under more permissive licenses.
  • Health Sciences show a greater leaning towards more restricted licenses. In Fully OA journals there is roughly a 50/50 split between license types. In Hybrid journals, restricted licenses outnumber permissive ones by around 2:1. This is driven by Medicine in particular. Nursing ratios move closer to the market averages.
  • Social Sciences show a slightly greater use of restricted licenses compared with market averages.
  • Physical Sciences make the greatest use of permissive licenses. In Fully OA journals, permissive licenses outnumber restricted licenses by over 3:1 (compared with the 2:1 market average). Within Engineering this increases to 3.5:1. In hybrid journals the ratio is almost 2:1 (compared with just over 1.1:1 Market average).

This year, we have worked with OASPA on their annual survey. Figure 2 below shows an excerpt from a longer blog post we put together to show the results. The chart further supports the difference of patterns between different samples of publishers. The dominance of CC BY usage in fully OA journals reflects the make-up of OASPA members.


The data support what many of us know from anecdotal discussions. The majority of OA output is published under more permissive licenses. In particular the CC BY license dominates, especially in fully OA journals. It’s useful to see this confirmed across the market, and also to see how the figures differ for the large publishers.

However, licenses that allow sharing with some restrictions remain significant, and show no signs of collapsing. Many publishers continue to make use of them. In fact, restricted licenses cover the majority of output in some disciplines. Subscribers to our database can examine this in more detail and also look at longer term trends.

Of course, we have yet to see the effects of large-scale mandates such as Plan S, or the UKRI’s newer policies, on the numbers. Common sense suggests that the proportions of CC BY licensed output are likely to increase, and we look forward to revisiting the data in the coming months and years.

This article is © 2021 Delta Think, Inc. It is published under a Creative Commons Attribution-NonCommercial 4.0 International License. Please do get in touch if you want to use it in other contexts – we’re usually pretty accommodating.


Wiley Announces the Acquisition of Hindawi – January 5, 2021

“John Wiley & Sons, Inc. announced the acquisition of Hindawi Limited, an innovator in open access (OA) publishing and one of the world’s fastest growing scientific research publishers, for a total purchase price of $298 million…Hindawi, privately held and headquartered in London, has a robust portfolio of over 200 peer-reviewed scientific, technical, and medical journals, a highly efficient publishing platform, and a low-cost infrastructure.”

Nature journals debut open-access models – December 18, 2020

“Two newly announced options for authors bring the publications into compliance with Europe’s Plan S initiative, but the fees exceed those of other open-access journals.”

Elsevier expands Open Access options for Cell Press Journals from January 2021 – December 18, 2020

“Elsevier, a global leader in research publishing and information analytics, today announced that the Cell Press port­folio of journals will be expanding open access publishing options for authors from January 1, 2021.”

Physics societies unite in support of open access – December 15, 2020

“Major physics societies, which support physical science researchers with the publication of more than 75,000 peer-reviewed journal articles each year, have joined forces to show their commitment to open access (OA) for physics research. The group comprises 16 societies.”

Simba reports on open access book market in Open Access Book Publishing 2020-2024 – December 8, 2020

“In its report—Open Access Book Publishing 2020-2024—Simba reports on an open access book market that declined for the first time since tracking was initiated in 2013. It concludes that title output declined 18.7% in 2019 with 2,801 open access books published against 3,445 in 2018, according to titles listed by publication year in the Directory of Open Access Books.”

eLife shifting to exclusively reviewing preprints – December 2, 2020

“eLife has announced that it is transitioning to a new ‘publish, then review’ model for science publishing, in which the journal will exclusively review preprints and its editors and reviewers will focus on producing high-quality peer reviews that will be made public alongside the preprints.”

The State of Open Data 2020 – Global Attitudes towards Open Data – December 1, 2020

“Figshare, the online digital repository for academic research, launched its annual report The State of Open Data 2020. The report is the fifth in the series and is the result of a collaboration between Figshare, Digital Science, Springer Nature and other leading industry and academic representatives.”

Gold Open Access research has greater societal impact as used more outside of academia – November 30, 2020

“The latest results of research carried out between Springer Nature, the Association of Universities in the Netherlands (VSNU) and the Dutch University Libraries and the National Library consortium (UKB), illustrates a substantial advantage for content published via the Gold OA route where research is immediately and freely accessible.”

Nature journals reveal terms of landmark open-access option – November 24, 2020

“From 2021, the publisher will charge €9,500, US$11,390 or £8,290 to make a paper open access (OA) in Nature and 32 other journals that currently keep most of their articles behind paywalls and are financed by subscriptions. It is also trialling a scheme that would halve that price for some journals, under a common-review system that might guide papers to a number of titles.”

cOAlition S releases the Journal Checker Tool, a search engine that checks Plan S compliance – November 18, 2020

“cOAlition S is excited to announce the release of the Journal Checker Tool (JCT) in beta. The JCT is a web-based tool which provides clear advice to researchers on how they can comply with their funder’s Plan S-aligned Open Access policy when seeking to publish in their chosen journal.”


January 6, 2021

International Drug Abuse Research Society and International Narcotics Research Conference launch new journal with Frontiers

“The International Drug Abuse Research Society (IDARS) and the International Narcotics Research Conference (INRC) are collaborating in partnership with Frontiers on a new journal: Advances in Drug and Alcohol Research (ADAR). The journal will launch in April 2021 on Frontiers’ Publishing Partnerships platform.”

December 10, 2020

Cambridge University Press launches Environmental Data Science journal

“Cambridge University Press is launching a new, Open Access journal – Environmental Data Science – dedicated to the potential of artificial intelligence and data science to enhance our understanding of the environment, and to address climate change.”

December 10, 2020

Combinatorial Theory Journal Launches on UC’s eScholarship Publishing Platform with Innovative Open Access Funding Model

“The eScholarship Publishing program of the University of California is pleased to announce the launch of Combinatorial Theory, a new mathematics journal expecting its first issue in Spring 2021… Combinatorial Theory is an open access publication, with no fees for authors or readers.”

December 1, 2020

De Gruyter to publish the Journal of Osteopathic Medicine

“The American Osteopathic Association (AOA) and De Gruyter are pleased to announce a publishing partnership for the Journal of Osteopathic Medicine (JOM). Starting in January 2021, the JOM will be published by De Gruyter and transition to an open access publishing model.”

December 1, 2020

IOP Publishing expands open access journal portfolio with the launch of Neuromorphic Computing and Engineering

“IOP Publishing (IOPP) has launched a new, multidisciplinary, open access (OA) journal devoted to the design, development and  application of artificial neural networks and brain-inspired systems towards advancing scientific discovery and realising emerging new computing technologies.”

November 24, 2020

IOP Publishing unveils new open access environmental journal series

“IOP Publishing (IOPP) is launching a suite of new open access (OA) environmental journals, marking the creation of the Environmental Research series… The Environmental Research series will grow throughout 2021 with the introduction of other sister titles that will collectively cover all major areas of environmental research.”

November 18, 2020

AAAS announces new Science Partner Journal, Ultrafast Science

“The American Association for the Advancement of Science (AAAS) is pleased to announce the launch of new Science Partner Journal, Ultrafast Science, published in affiliation with Xi’an Institute of Optics and Precision Mechanics (XIOPM)… The journal is currently open for submissions and will publish under a Creative Commons Attribution License (CC BY).”

November 17, 2020

ASM to Launch New Journal, Microbiology Spectrum, Committed to Open Science

“The American Society for Microbiology will launch a new journal in Spring 2021, Microbiology Spectrum, ASM’s sixth fully open-access journal. Led by an international team of scientists actively engaged in microbiology research, Microbiology Spectrum will welcome technically sound research from all domains of basic, applied and clinical microbiology.”

November 11, 2020

AAAS announces New Science Partner Journal, Health Data Science

“The American Association for the Advancement of Science (AAAS) is pleased to announce the launch of new Science Partner Journal, Health Data Science, published in affiliation with Peking University (PKU)… The journal is currently open for submissions and will publish under a Creative Commons Attribution License (CC BY).”