Each year, Delta Think’s OA Market Sizing analyzes the value of the open access journals market. This is the revenue generated by providers or the costs incurred by buyers of content. Our analysis this year shows that the open access market has had an exceptional year of growth in 2020. The effects of COVID-19 and exchange rate changes have compounded OA’s underlying strong growth. Based on current trends, we estimate it to have been worth around $975m in 2020 and on track to grow to over $1.1bn in 2021.

Headline findings

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

We estimate that the OA market grew to around $975m in 2020.

  • The 25% increase over 2019 is significantly larger than the growth in the underlying scholarly journals market, which is typically low to mid-single digit. It is larger than expected for the OA market.
  • Growth in OA will remain above that of the underlying scholarly journals market. The open access market is on target to be over $1.1bn in 2021.
  • Around 36% of all scholarly articles were published as paid-for open access in 2020, accounting for just under 9% of the total journal publishing market value.
  • We anticipate a 2020-2023 CAGR of 14% in OA output and 17.6% in OA market value.

A note about our method

We aggregate data from our exclusive annual publisher survey – which now covers around two thirds of indexed global output, and just under half of everything in Crossref – and project it against patterns in the Unpaywall and OpenAPC data sets to model the entire market.

The data sources change over time, so we restate our findings each year to reflect the latest data available. Even a few weeks’ difference in timing of analysis can make a significant difference in results.

We normally base our analysis on underlying trends to avoid misleading headlines resulting from short term fluctuations we see in the data. However, where there are exceptional off-trend events – as we are witnessing at present with COVID-19 – we must incorporate them into our models.


  • The effects of COVID-19 have driven exceptionally high growth in scholarly output across all access models. OA output in hybrid journals has been boosted more than other OA output.
  • Historically, there appears to be more OA output that we have previously thought and it is growing at a faster rate.
  • Exchange rate fluctuations have compounded the exceptional growth in publishing activity, increasing reported revenues further above long-term trends.
  • We are still in the middle of the exceptional effects of COVID-19. It will likely be another 18-24 months before we gain sufficient distance to observe any changes to underlying trends.
  • The long-term growth curves show signs of flattening out to a steady state of just over 15% in both volume and value of OA. This represents a slight uplift in long-term growth rates compared with previous years’ data, due to increased adoption of OA and rising prices.
  • Hybrid revenues realized per article published are higher than those published in fully OA journals, and the gap appears to be widening.

The trends mask important nuances. Individual publishers exhibit different dynamics, which is not surprising given how varied their portfolios can be.

  • Publishers may produce less than trend in one year but make up the shortfall in the following year, or vice-versa. As a result, we see fluctuations in the overall numbers from year to year. However, the underlying trends appear to remain consistent. Almost all publishers have seen exceptional rises in submissions and publication output in the wake of COVID-19.
  • Revenues generated per article vary widely depending on the sample. E.g., the OpenAPC data suggest higher-than-average numbers, reflecting their focus on higher output and (wealthier) European institutions. Meanwhile, some segments of the market may see fully OA APCs that are higher than hybrid APCs (counter to the market averages).
  • Regions vary greatly. Waivers offered to low-GDP countries and how OA is funded are highly variable.


Last year we noted that publishing activity would increase in the wake of COVID. This appears to have been borne out. The exceptional growth in 2020 is driven by the events of COVID-19 and compounded by fluctuations in exchange rates.

The growth rates may seem high, but all publishers in our annual survey reported significant increases in their publishing activities. We don’t comment on individual publishers’ revenues, as our survey is confidential. However, investor reports published by the publicly listed corporates do go into detail and bear these trends out.

As COVID-19 is (we hope) an exceptional event, the exceptional growth in 2020 should be temporary. It will likely take 18-24 months before we can observe the length of the temporary uplift and how much of it will perpetuate into long-term trends.

The underlying drivers we noted last year remain in play. Next month we will reflect on these in more depth. However, for now, the one key trend worth noting is how the OA model can respond quickly to changes in demand. Subscriptions cannot grow as quickly. They are paid in advance, so increases in activity can only be monetized in retrospect – especially where publishers are locked into multi-year deals – and only assuming the market will bear the price increases. It seems that the growth in the journals market is largely due to growth in OA.

COVID-19 has therefore served to boost the open access market.

Subscribers to our OADAT tool can see detailed breakdowns of fully OA, hybrid and other revenues, along with projections the coming years, and more detailed analyses and commentary about market drivers.

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.


Cambridge University Press reaches major Open Access agreement in Australia and New Zealand – October 14, 2021

“Cambridge University Press and the Council of Australian University Librarians (CAUL) have reached a transformative agreement to support Open Access (OA) publishing in Cambridge Journals for 2022.”

New collaboration between SCOAP³ For Books and OAPEN: Open Access Books in Particle Physics – October 1, 2021

“SCOAP³ – the Sponsoring Consortium for Open Access Publishing in Particle Physics – is collaborating with OAPEN as part of its latest open access book initiative. Since the introduction of SCOAP³ in 2012 under the auspices of the European Organization of Nuclear Research (CERN), the transition to open access for scientific articles in particle physics has progressed rapidly.”

UNESCO supports the launch a new version of the Global Open Access Portal (GOAP.info) – September 29, 2021

“The new Global Open Access Portal (GOAP.info) presents access to a wide array of Open Access resources worldwide, through an advanced user interface design. GOAP.info allows users to browse dynamic Open Access contents via both a text-based search and a map-enabled country search option.”

Rockefeller University Press Secures Transformative Journal Status from cOAlition S – September 28, 2021

“Rockefeller University Press (RUP) has attained Plan S compliant Transformative Journal status from cOAlition S. Authors receiving funding from members of cOAlition S may be eligible to have their Immediate Open Access (OA) fees covered in Journal of Cell Biology (JCB), Journal of Experimental Medicine (JEM), and Journal of General Physiology (JGP).”

Iowa State University, Knowledge Unlatched, and JMIR Publications Partner to Launch Open Access Fund Management System – September 28, 2021

“Iowa State University, Knowledge Unlatched (KU), and JMIR Publications have signed an agreement to pilot the new Oable workflow management tool to monitor funds and administer Iowa State’s payments for eligible publications in the JMIR Publications portfolio… The pilot will run from September 1, 2021, to August 31, 2023.”


October 7, 2021

Three new academic journals to meet growing demand for environmental research

“IOP Publishing (IOPP) is launching three new, fully open access (OA) journals, extending the publisher’s Environmental Research series… Environmental Research: Health (ERH) and Environmental Research: Climate (ERCL) will both open submissions from today. The third new journal, Environmental Research: Ecology (ERE) will open for submissions later in 2021.”

October 6, 2021

AAAAI’s New Open Access Journal Is Now Accepting Manuscript Submissions

“The Journal of Allergy and Clinical Immunology: Global (JACI: Global), a new Gold Open Access journal from the American Academy of Allergy, Asthma & Immunology (AAAAI), is now accepting manuscript submissions… The first issue of JACI: Global will publish in February 2022 during the AAAAI Annual Meeting in Phoenix, Arizona.”

September 29, 2021

Mary Ann Liebert, Inc. to launch Integrative Medicine Reports in collaboration with the Academy of Integrative Health & Medicine

Integrative Medicine Reports, a new peer-reviewed, open access journal published by Mary Ann Liebert, Inc , is officially open to receive manuscript submissions… The journal will publish in a fully open access format on a continuous basis and launch as the Official Journal of the Academy of Integrative Health & Medicine (AIHM).”

September 21, 2020

Karger Publishers Further Expands into Open Access and Open Science

“Karger Publishers has ‘flipped,’ or converted, the journals Pulse and Human Heredity from the subscription model to Open Access (OA) for 2022. In the past few years, Karger Publishers has flipped over a dozen journals to OA, which now comprises about a third of the overall journal program.”