calendar tag arrow download print
fact sheet
20 December 2019

Open access to research publications

access peerreview journal
More and more research publications by Dutch authors are available as “open access”, meaning that anyone can read them free of charge. Of the research publications that appeared in 2018 in which a Dutch author was involved, 57% are freely available. This puts the Netherlands ahead of neighbouring countries. An increasing proportion of these open-access publications are available via the “gold” and “green” routes. The share of publications that is available as open access is growing fast. 2016 and 2017 have seen a growth of 6 percentage points per year. 2018 shows a slower growth rate: of 3 percentage points. Even so, the target of 100% open access by 2020 is still a long way from being achieved.

The journals in which researchers publish their articles are managed by publishers. Each journal subjects submitted articles to internal screening and to a peer-review process in which fellow researchers assess their quality. When an article is published, the copyright often becomes the property of the publisher. Anyone who wants to read the article has to pay to do so. Universities and institutes therefore conclude agreements with publishers so as to make those publishers’ journals available to their staff and students.

Aim: 100% open access by 2020

The publication model is under discussion: it involves high costs for readers. Many believe that research funded by public means should be publicly available. Therefore, organisations are working internationally to reverse to open access. The Netherlands has the aim of publishing 100% of research publications as open access (Dekker, 2013; Ministry of Education, Culture and Science, 2017). In September 2018, the Netherlands Organisation for Scientific Research (NWO), the European Research Council (ERC), and ten other European research funding bodies signed “Plan S” (Science Europe, 2018). Up to today, six other funding bodies and five international organisations have also joined Plan S. This means that research resulting from all calls by these organisations published as of january 1, 2021 (including Horizon Europe),  must be published as open access (Science Europe, 2019: NWO, 2019).

What is open access?

Open access means that research publications are available to the reader free of charge, for example to read, download, distribute, or edit – as long as the original author is credited (BOAI, 2002).

There are various types of open access. They differ as to the version of the article that is made available, the location where it is available, and/or the conditions under which it is available. These different types are indicated by a colour: gold, green, or bronze.

In this factsheet we distinguish the following three open access “routes”:

Form Version Place of publication User rights
Gold route The publisher's version Open access journal or platform. or freely accessible in a subscription-based journal (also known as 'hybrid' journals) Read and use
Bronze route The publisher's version On the publisher's website or platform Dependent on license
Green route Peer-reviewed version A repository managed by an academic institution Dependent on license

The Dutch government strives after open access through the gold route (Dekker, 2013). The Association of Universities in the Netherlands (VSNU) negotiates with several publishers to reach that goal. Plan S strives after open access through the gold or green route. They reject the hybrid route and no longer offer financial support for publications in hybrid journals. The exception to this is when there is a so-called transformative agreement with either the publisher or the journal to switch to open access in the long run.

Open access in the Netherlands

As the graph above shows, the proportion of research articles published open access in the Netherlands rose from 19% of publications in 2002 to 57% in 2018. Recent measurements of open access by Data Archiving and Networked Services (DANS) (52% in 2018) and the VSNU (only universities, 54%) reveal a similar picture. Here, bronze is not included.

The graph below also shows the “routes” by which articles become available. Some are available by more than one route. The category “Green & Gold” indicates articles that are available to the reader free of charge via both a journal (gold) and a database (green). The author or the institution where he/she works has then chosen to also upload the publication to a database.

Many of the articles available via the green route are also available via the bronze route. These are shown in the graph as green, because in that case the rights to reuse are clear and there is little chance that the article will disappear behind a payment wall again (Van Leeuwen et al., 2017).

Most open access publications are published via the Green route. 86% of all open-access publications from 2018 are available (inter alia) via a database, i.e. 45% of the total number of Dutch publications in that year.

The Gold route has grown fastest. The proportion of open-access publications published via the gold route (inter alia) rose from 5% of publications in 2002 to 61% in 2018. The majority (54%) of these gold open-access publications are to be found in an open-access journal. Gold open-access publications account for 34% of the total number of Dutch publications in that year. The green route is also becoming more important.

More and more articles are available via both the Gold and Green routes. Of the “gold publications” from 2018, 84% are also available as “green”. Conversely, 64% of the “green publications” from 2018 are also available as “gold”. This shows that authors and institutions are increasingly making use of the possibility of also including an article in a database that has been published by a publisher as open access.

Open access in an international context

The following graph shows that open access is increasing in all countries and that the Netherlands is the leader as regards the proportion of publications that are published as open access. With 57% in 2018, the Netherlands is on par with the United Kingdom. The Netherlands is ahead of the other neighbouring countries. In Belgium, 44% of Web of Science publications are available as open access, in Germany 39%, and in France 37%.

That the Netherlands is an international leader in open access is also confirmed by other analyses, for example the ERA Progress Report 2018, which provides an international comparison of the proportion of open-access publications. The 2017 analysis by Van Leeuwen et al. (CWTS) also shows that the Netherlands, with a proportion of 37%, is the leader among the reference countries. It is followed by the United Kingdom, Belgium, Ireland, and Sweden, each with 34% open access.

Impact of open access

Making open access possible requires a change in the publication process. This raises questions about new publishing methods, the funding of open-access publications, maintaining the quality of publications, and the important role that publications play in ensuring the quality of research (see for example: Finch, 2012; Pinfield, 2015; AWTI, 2016). Publishers apply a variety of business models for open-access publication of articles. Government and the bodies that fund research also impose requirements for the publication conditions, which may conflict with one another.

It is not easy to determine how the costs for open access publishing compare with those for the existing publication model. Among other things, this depends on how the open-access system is designed and whether publishers will maintain their strong position in the market. It is conceivable that a system in which all research publications are open access will ultimately be cheaper for knowledge-users than the conventional system of paying for access to subscription journals (Houghton et al., 2009; Witmond et al., 2014). But it is equally possible that the costs for a fully open-access system will in fact be higher than for the conventional system (AWTI, 2016; CPB, 2016). The question is who will bear the costs of the transition and of open-access publishing.

Finally, quality is an issue because the status of the journals in which researchers publish their findings and the peer-review system involved in publication are essential components of research quality assurance and the assessment of researchers. Open access publishing might have an effect on citation-impact. Research from Van Leeuwen and Schneider (2019) has shown that the impact-score and journal-impact of golden open access articles (excl. hybrid) is slightly below that of articles from closed journals. The citation and journal impact of articles published via the hybrid or bronze routes is higher than that of articles in traditional journals. Articles available via the green route, for a large part also available through one of the other routes, are in between.

About de data

More details about open access in the Netherlands are available in the underlying database.

Collecting data about open access is still work in progress. The information on the open-access status of articles in databases is not always complete, because it has not yet been conclusively established for each publication whether it is in fact available as open access. The reliability and validity of the measurement methods is therefore always open to questioning.

For the present factsheet we made use of data from Web of Science (WoS). WoS works with Impactstory to indicate which publications in WoS are open access and to link directly to those versions. Impactstory is a non-profit organisation dedicated to making research accessible. Among other things, it has developed Unpaywall, a database with more than 20 million open-access versions of research articles (

Piwowar et al. (2018) have shown that 97% of the articles identified as being open access in that database are in fact such. In that respect, the database is highly reliable. However, Unpaywall identifies only 77% of articles that are actually open access as being such. The open-access percentages for WoS therefore probably underestimate the reality.

Another limitation of the WoS database is that the natural and biomedical sciences are represented relatively strongly, while the social sciences and humanities are represented significantly less (Van Leeuwen, 2013; Mongeon & Paul-Hus, 2016).

Van Leeuwen et al. (2017) (CWTS) combine Web of Science data with multiple sources so as to determine the open access status (without ResearchGate and Scihub). They include only gold and green open access so as to ensure the sustainability and legality of the open-access status of articles.


  • AWTI (2016). Durven delen. Op weg naar een toegankelijke wetenschap. 
  • Björk, B. (2017). Gold, green and black open access. Opiniestuk: DOI:
  • Budapest Open Access Initiative (BOAI, 2002).
  • Council of the European Union (2016), 27-05-2016, the transition towards an Open Science system – Council Conclusions.
  • CPB (2016). Kansrijk wetenschapsbeleid. The Hague: Centraal Planbureau. 
  • Data Archiving and Networking Services, NARCIS,
  • Dekker, S. (2013). Kamerstukken II 2013/2014, 31 288, nr. 354. Brief van de staatssecretaris van Onderwijs en Wetenschap.
  • European Commission (2016), European Research Area, Progress Report 2016. Technical report. 
  • Finch, J. (2012). Accessibility, sustainability, excellence: How to expand access to research publications. Report of the Working Group on Expanding Access to Published Research Findings.
  • Houghton, J., J. de Jonge & M. van Oploo (2009). Costs and Benefits of Research Communication: The Dutch Situation. Leiden: EIM and Research voor Beleid.
  • Koens, L. et al. (2018). Balans van de wetenschap 2018. Den Haag: Rathenau Instituut. Link:
  • Martín-martín, A., R. Costas, T. van Leeuwen & E. Delgado López-Cózar (2018), Unbundling Open Access dimensions: a conceptual discussion to reduce terminology inconsistencies. Proceedings of the 2018 STI conference, 12-14 September 2018, Leiden
  • Ministry of Education, Culture and Science (2017, 9 februari), National Plan Open Science. DOI:
  • Mongeon, P. & A. Paul-Hus (2016).  The journal coverage of Web of Science and Scopus: a comparative analysis. Scientometrics (2016) 106: p. 213–228
  • NWO. (2019). Finale versie van Plan S gepubliceerd.
  • Open
  • Open
  • Pinfield, S. (2015). Making open access work: the ‘state-of-the-art’ in providing open access to scholarly literature. Online Information Review, 39:5. 604-636. DOI:
  • Piwowar, H., J. Priem, V. Larivière, J.P. Alperin, L. Matthias, B. Norlander, A. Farley, J. West & S. haustein (2018). The State of OA: a large-scale analysis of the prevalence and impact of Open Access articles. PeerJ. DOI: 10.7717/peerj.4375/supp-1
  • Science Europe (2018). cOAlition S, making Open Access a reality by 2020. A declaration of commitment by public research funders. Beschikbaar via:
  • Science Europe (2019). Plan S: principles and implementation.
  • Van Leeuwen, T.N. (2013). Bibliometric research evaluations, Web of Science and the social sciences and humanities: a problematic relationship? Bibliometrie - Praxis und Forschung, band 2 DOI:
  • Van Engelshoven, I.(2019). Kamerstukken II 2018/2019, 31 288, nr. 793. Brief van de minister van Onderwijs, Cultuur en Wetenschap.
  • Van Leeuwen T.N., Meijer I, Yegros-Yegros, A & Costas R (2017). Developing indicators on open Acess by combining data from diverse data sources. Proceedings of the 2017 STI-Conference, 6-8 september, Parijs
  • Van Leeuwen, T. & J. Schneider. (2019). Open access uptake of universities in the R-quest countries under various OA mandates. Proceedings of the 2019 ISSI-conference.
  • Vereniging Samenwerkende Nederlandse Universiteiten (2017). Percentages of open access publications in 2016.
  • Web of Science, Clarivate Analytics.
  • Witmond, B., N. van Nimwegen & M. Zwart (2014). Marktonderzoek open access. Eindrapport kostencijfers. Rotterdam: Ecorys.