Open access and ranking signals: how free access to research is reshaping university evaluation

The open access movement and ranking relevance

Open access to research—the principle that scholarly publications should be freely available to anyone with an internet connection—has moved from a niche advocacy position to a mainstream policy priority. Major research funders, including the European Commission through its Horizon Europe program and the US National Institutes of Health through its Public Access Policy, now require funded research to be made openly available. This shift is reshaping how university research output is measured, and ranking systems are beginning to reflect it. The inclusion of open access indicators in systems such as the CWTS Leiden Ranking and U-Multirank signals a growing recognition that research visibility and accessibility are dimensions of university performance.

For users of rankings, open access indicators offer new signals about an institution's commitment to knowledge dissemination and research equity. A university that makes its research freely available may have greater global impact than one that publishes behind paywalls, even if its raw citation counts are similar. This is particularly relevant for users in developing countries, where access to subscription journals is often limited. The growing availability of open access data means that this dimension of performance will likely become more prominent in rankings over the coming years.

How open access indicators are measured

Open access measurement in rankings is still evolving, and different systems use different approaches. The CWTS Leiden Ranking includes indicators that break down publications by open access type: gold open access, where the published version is freely available on the journal's website; green open access, where a version is deposited in an institutional or subject repository; hybrid open access, where authors pay to make individual articles open within otherwise subscription journals; and bronze open access, where articles are made free to read without a formal open license. These categories reflect the diversity of open access routes that universities employ.

U-Multirank includes open access indicators in its research dimension, measuring the proportion of an institution's publications that are available through open access channels. THE has explored open access as part of its broader research environment metrics. The underlying data for these indicators comes from databases such as Unpaywall, which tracks the open access status of millions of publications, and from the bibliometric databases themselves as they improve their open access tagging. The measurement infrastructure for open access is improving rapidly, but coverage gaps remain, particularly for publications in non-English languages and for book chapters and monographs.

Open access and institutional strategy

The inclusion of open access in rankings creates new strategic considerations for universities. Improving open access rates can raise an institution's visibility in rankings, particularly in systems such as Leiden that make open access a separate reporting category. Universities may respond by adopting open access mandates, investing in institutional repositories, negotiating transformative agreements with publishers, and supporting author publication charges. These are generally positive developments from the perspective of research dissemination, but they also raise questions about equity: wealthy universities can afford to pay article processing charges for gold open access, while less well-resourced institutions may struggle.

There are also methodological cautions. Open access rates are influenced by disciplinary norms: some fields, such as physics with its strong preprint culture through arXiv, have long traditions of open access, while others, particularly in the humanities, have been slower to adopt open models. Funders in some countries mandate open access more strongly than in others, creating national-level variation that is unrelated to institutional commitment. Open access indicators are also relatively new in ranking systems, meaning that historical time series are limited and trends should be interpreted cautiously. Users should view open access signals as one dimension among many, not as an overriding indicator of quality.

Future directions and user guidance

As open access becomes the global norm for research dissemination, its role in rankings is likely to expand. Future ranking indicators may incorporate not just the proportion of open access publications but also measures of research data sharing, open educational resources, and citizen science engagement. These broader open science indicators would move beyond counting publications to assess institutional commitment to transparent, collaborative, and publicly engaged research. The UNESCO Recommendation on Open Science, adopted in 2021, provides an international policy framework that may accelerate the development of such indicators.

For ranking users today, open access indicators can help identify institutions that are leading the transition to more open research practices. If you value research accessibility—as a student wanting to read your professors' work, as a researcher in a developing country, or as a citizen interested in publicly funded research—open access rates are a relevant factor. Check which open access route is most common at the institutions you are considering, as this may affect the long-term accessibility of their research. Verify open access claims against publicly available databases, and remember that open access is a means to research dissemination, not an end in itself. Rankings should continue to prioritize indicators of research quality and impact while using open access as a complementary signal of accessibility and transparency.