An official website of the United States government
Open-Access Publishing in a Global Context
Open-access (OA) publications are peer-reviewed research articles that are accessible online to any reader without requiring a journal subscription or payment. These publications allow global researchers and other readers access to scientific research and have reshaped the structure of scientific publishing. Government and private funders, institutions, and scientists themselves are increasingly concerned with the availability of S&E publications through OA sources, with some funders requiring grantees to publish their results in OA journals. This InfoBrief explores global patterns of OA publication output and scientific impact from 2003 through 2022 using Scopus, a bibliometric database of publication metadata, which includes the OA status of research publications.
OA publications can be classified based on the level of access and temporality of access. Gold OA refers to journals that are entirely open access as a matter of policy. Other Journal-Based OA types include Hybrid OA, journals that publish a mix of Closed-access and OA articles, and Bronze OA, journals that make articles conditionally available (e.g., after an embargo period). Green OA denotes articles that are published in Closed-access journals but self-archived by authors in independently open repositories. Some journals may require authors to pay article processing charges for Gold OA, Hybrid OA, or Bronze OA—but not universally. Although an article may be available through multiple OA avenues, such as a Gold OA article that is also available as Green OA through a preprint archive for the purpose of analysis, articles are designated into mutually exclusive OA categories in order from Gold OA, Other Journal-Based OA (including Hybrid and Bronze), and Green OA. Closed-access articles are defined as those that are not available as any OA type. OA publication patterns vary among countries and economies and can reflect the prominence of OA as a mode of publication by authors at institutions within those countries and the international impact of OA publications.
Production of Open-Access Articles Over Time
Since 2003, the number and share of OA articles has grown from an infrequent type of peer-reviewed publication to almost half of global publications in 2022. The total number of articles published as Gold OA has increased from 19,089, or 2% of global publications, in 2003 to 991,805, or 30% of all publications, in 2022 (figure 1). The share of Closed-access articles decreased from 58% of global publications in 2003 to 45% in 2022. However, during the same period, the number of Closed-access articles increased in absolute terms with a growth rate of 112%, compared to a growth rate of 5,096% in the number of Gold OA articles. The number of articles published annually as Green OA and Other Journal-Based OA grew by 228% and 198%, respectively. However, both Green OA (from 6% to 8%) and Other Journal-Based OA (from 9% to 10%) showed modest increases of their shares of articles published globally over the same period.
| Publication year | Closed access | Green OA | Other Journal-Based OA | Gold OA |
|---|---|---|---|---|
| 2003 | 716,290 | 79,136 | 111,900 | 19,089 |
| 2004 | 749,747 | 89,408 | 119,386 | 22,584 |
| 2005 | 846,261 | 110,069 | 124,548 | 30,095 |
| 2006 | 927,801 | 126,067 | 129,641 | 41,497 |
| 2007 | 983,096 | 145,872 | 134,450 | 49,937 |
| 2008 | 1,001,082 | 170,936 | 145,627 | 67,063 |
| 2009 | 1,040,201 | 191,714 | 158,239 | 83,949 |
| 2010 | 1,083,721 | 203,325 | 162,058 | 106,460 |
| 2011 | 1,119,780 | 211,503 | 178,121 | 139,931 |
| 2012 | 1,137,037 | 220,373 | 189,811 | 178,889 |
| 2013 | 1,160,217 | 238,154 | 200,600 | 208,857 |
| 2014 | 1,176,541 | 246,834 | 214,518 | 257,864 |
| 2015 | 1,186,666 | 259,016 | 218,231 | 310,487 |
| 2016 | 1,209,852 | 266,903 | 238,672 | 359,083 |
| 2017 | 1,217,879 | 283,349 | 241,314 | 430,867 |
| 2018 | 1,277,758 | 290,252 | 249,655 | 498,502 |
| 2019 | 1,332,273 | 294,347 | 257,418 | 634,366 |
| 2020 | 1,286,235 | 295,769 | 294,709 | 793,327 |
| 2021 | 1,372,042 | 310,619 | 325,757 | 962,403 |
| 2022 | 1,520,454 | 259,813 | 332,915 | 991,805 |
OA = open access; S&E = science and engineering.
Articles refer to publications from a selection of conference proceedings and peer-reviewed journals in S&E fields from Scopus. Articles are classified by their year of publication. OA types are mutually exclusive. For articles published under multiple OA types, the article will be counted as part of only the first type it matches in this list: Gold OA, Other Journal-Based OA, or Green OA. Summing all OA and Closed-access article counts results in a smaller number of articles than for all S&E because the access status of some articles (e.g., those without digital object identifiers) cannot be reliably ascertained. Green OA articles are published in toll-access journals but archived in an OA archive, or "repository." These repositories may be discipline specific (like arXiv) or institutional repositories operated by universities or other institutions. Green OA articles may be published versions or preprints and can have any license or no license. Bronze OA (Other Journal-Based OA) articles are free to read on the publisher's website, without a license that grants any other rights. There may be a delay between publication and availability to read, and often articles can be removed unilaterally by the publisher. Hybrid (Other Journal-Based OA) articles are free to read at the time of publication, with an open license. These are usually published in exchange for an article processing charge. Gold OA articles have all the same characteristics as Hybrid OA articles but are published in all-OA journals, which are in turn called "Gold journals."
National Center for Science and Engineering Statistics; Science-Metrix; Elsevier, Scopus abstract and citation database, accessed April 2023.
Science and Engineering Indicators
Country-Level Ratios of Gold Open-Access to Closed-Access Publications
Global variation in the shares of Gold OA and Closed-access publications within countries and economies helps highlight geographical patterns in the tendency to publish Gold OA. The maps in figure 2 highlight this variation by showing country- or economy-level ratios between Gold OA publications and Closed-access publications. To calculate the ratio for each, the country- or economy-level number of Gold OA publications was divided by the number of Closed-access publications each year as a fractional count. The scale is centered around a 1:1 ratio. Ratios between 0:1 and 1:1 indicate authors publish Closed-access articles more frequently than Gold OA, while ratios over 1:1 indicate authors publish Gold OA articles more frequently than Closed access. Countries or economies with fewer than 10 fractionally counted publications (Gold OA and Closed-access articles combined) are excluded. This resulted in an analytic population of 159 countries or economies in 2012, 167 in 2017, and 182 in 2022.
