Delta Think’s OA Market Sizing shows that the open access market continues to grow faster than the underlying journals publishing market. (Market Size represents revenue generated by providers or, conversely, costs incurred to buyers of content.) We estimate it to have been worth $571m in 2017 and on track to grow to over $600m 2018. However important challenges remain: OA’s share of output is greater than its share of revenue, and its rate of growth appears to be slowing.


Updates to key industry indexes are released over the summer, and we combine these with benchmarks obtained from our publishers survey to size the market. Our models, examined in greater depth within the main Open Access Data & Analytics Tool, suggest these headlines for sizing:

  • In 2016, the global OA market was worth around USD $490m, and grew to around $570m in 2017.
  • The 16% increase between 2016 and 2017 is larger then the growth in the underlying scholarly journals market, which is typically low to mid single digit.
  • We expect growth rates in open access to fall over the coming years, but to remain above the underlying market rates. The open access market is on target for over $600m in 2018.
  • Around 23% of all scholarly articles are published as open access, accounting for just over 5% of total journal publishing market value.
  • The major selective indices suggest that there are around 4,000 fully OA journals, although there is an unindexed long tail of 10k-20k in the more inclusive indices.

The dynamics of the open access market remain varied and nuanced, with our overall takeaways as follows:

  1. The key driver of the open access market remains funders. When choosing journals in which to publish, researchers primarily consider relevance and reputation and do not place a high priority on business model. Funders’ appetites for open access vary by territory. Those in the EU have the strongest mandates, but those in the Far East, for example, incentivize publication based on Impact Factor as they seek to enhance reputations and advance careers.
  2. There is a clear two-tier open access marketplace. Data suggest a roughly 75/25 split between fully open access and hybrid journals respectively, by both value and volume. The balance between revenues from fully open access journals, hybrid, and other sources (considering offsetting deals) could be set to change. 2018 saw a number of high-profile consortia cancellations and emergence of policies such as Plan S. Although focused on the EU, these increasingly aggressive interventions around pricing are likely to slow the growth in the value of open access market overall.
  3. Growth in hybrid appears to have slowed down, due, we think, to two factors. First, the major commercial publishers have now transitioned the majority of their journals to offer hybrid options, and the resulting one-off spike in hybrid growth will therefore disappear. Second, our survey data may be masking open access revenues that are accounted for as part of combined deals, and not called out separately. (We intend to address this latter point in future surveys.)
  4. The relatively low share of open access market value compared with its share of output poses interesting questions. The interpretation depends on point of view taken towards open access. The data either suggest that OA’s cost effectiveness could lower systemic costs of publishing, or that we need to be realistic about systemic costs and global funding flows. Some of the true costs of open access may be hidden, as it forms part of combined deals, and may not be accounted for separately.
  5. The growth in uptake of open access is slow: 17+ years to comprise one-fifth of article output, and, at best, one-tenth of market value. Again, views vary as to whether the transition to open access is frustratingly slow or reassuringly measured.
  6. The long tail of unindexed fully open access journals suggest interesting possibilities. Quality, of course, does not imply quantity, but there are many journals from reputable publishers not yet indexed and Clarivate’s Emerging Sources Citation Index (ESCI) suggests that up-and-coming publications contain a higher proportion of output in fully OA journals. It could be argued that the proliferation of small independent journals that have emerged in the OA space echo the fragmented world of scholarly publishing in the post-war period of the last century – out of which the current established scholarly journals industry grew.


In looking at market sizing, we have concluded that the open access market is growing faster than the underlying scholarly publishing market, but that its growth is showing signs of slowing. We have put numbers on things not previously quantified, suggested underlying causes and drivers, and shared this with the community.

Perhaps, however, the biggest headline is that in 2018, the data available in the scholarly publishing ecosystem about the market remains so poor. We mentioned this in our market sizing update last year. Unlike other industries, scholarly publishing culture is not one of sharing, so it is difficult to measure the market directly and in a timely way. To offset this, we use confidential survey data to produce benchmarks and adjust for lags in industry data sources. We are delighted that four of the five largest STM publishers now participate in our survey, together with some eminent societies and smaller publishers. The data we gather remains confidential, but the averages we produce enable us to provide more updates and generate further information and insights into the future direction of open access publishing.


OpenAIRE and DuraSpace partner to support greater functionality in the global repository network – October 15, 2018

“On September 25, 2018, OpenAIRE and DuraSpace signed a Memorandum of Understanding (MoU). Both OpenAIRE and DuraSpace have a shared interest in a robust, interoperable, and functional network of repositories that provide value to the research community and contribute to Open Science and Open Access in Europe and the world.”

Open access at a crossroads – October 11, 2018

“European funders are forcing the issue on open access publishing, while the Trump administration reviews US policies on disseminating federally sponsored research.”

Recommendation on access to and preservation of Scientific Information – October 8, 2018

“The European Commission has released a new set of recommendations to the Member States that offer guidance and propose the best way to implement and support open science practices. The new recommendations include sections on incentives, rewards and require action plans from member states with concrete and measurable objectives. They are to replace the recommendations of 2012.”

KU Open Funding simplifies financing of Open Access books – October 5, 2018

“Knowledge Unlatched (KU), the leading Open Access marketplace, presents its central database for financing OA books. It enables numerous publishers to make their offerings transparent and thus enables scientists and libraries to find publication partners for book projects.”

Open Access Expert Rob Johnson Dissects “Plan S” on Copyright Clearance Center “Pop-Up” Webinar – October 5, 2018

“Copyright Clearance Center (CCC), a leader in advancing copyright, accelerating knowledge, and powering innovation, hosted a ‘pop-up’ webinar in advance of Frankfurt Book Fair – Get Smart About ‘Plan S’ – featuring Open Access (OA) expert Rob Johnson, founder and director of the UK’s Research Consulting on Tuesday, 2 October 2018.”

OASPA Offers Support on the Implementation of Plan S – October 2, 2018

From the members of OASPA’s Board of Directors: “OASPA welcomes the launch of Plan S, recently announced by a coalition of 11 leading funding agencies from across Europe, with the support of the European Commission and the European Research Council, as an important step in the transition towards full and immediate open access for scholarly research.”

Congress Renews $5 Million Open Textbook Pilot For Second Year – September 26, 2018

“The U.S. Congress reaffirmed the national role of ‘open’ in the path to college affordability by renewing the $5 million federal Open Textbook Pilot for another year. Contained in the broader Department of Defense and Labor, Health and Human Services, and Education Appropriations Act of 2019, the program answers a call from students across the country to tackle textbook costs as a barrier to higher education.”

Project MUSE offers nearly 300 “HTML5” open access books on re-designed platform – September 21, 2018

“Nearly 300 open access (OA) books are now available from Project MUSE, the highly-acclaimed online collection of humanities and social science scholarship, on a newly designed platform that represents a major step forward in OA publishing in these fields. The books will be delivered in a highly-discoverable and adaptable format using user-friendly HTML5, rather than static PDFs.”

PKP and SciELO announce development of open source Preprint Server system – September 21, 2018

“In recognition of SciELO’s twentieth anniversary, the Public Knowledge Project (PKP) and SciELO Program are entering into an agreement to develop a Preprint Server system on the principles that have guided these two organizations over the last two decades.”

ALPSP member briefing on Plan S – September 21, 2018

“ALPSP welcomes engagement with Science Europe, the European Commission and the ERC to maximise the potential for a transition in research culture to offer the best opportunity for the continuing advancement of discovery and support of a vibrant research community both within Europe and beyond.”


October 16, 2018

Frontiers launches new open access journal: Frontiers in Artificial Intelligence

“Frontiers in Artificial Intelligence is an innovative, new Open-Access journal that provides a home for research and collaborations in this exciting field. Frontiers in Artificial Intelligence will open for submissions on 30 October 2018 and will cover a broad range of topics in artificial intelligence as well as its various forms and applications.”

July 31, 2018

Volcanica: A New Diamond Open Access Journal

“Volcanica is a broad-scope open access international journal promoting research into all aspects of volcanology, including physical phenomena and their impact on society, health, and the environment. Volcanica is committed to establishing a publication system that is both Free to publish and Free to access.”