Open access intuitively offers many advantages. However, surveys show that some scientists still have reservations. In the last decade, many empirical studies have been published, providing evidence regarding such hopes and concerns. What was missing is a literature review on the effects of open access that provides a comprehensive overview of these empirical findings. To fill this gap, Technische Informationsbibliothek (TIB) on behalf of the German Federal Ministry of Education and Research (abbreviated BMBF) recently completed a study named “Wirkungen von Open Access. Literaturstudie über empirische Arbeiten 2010 –2021”. The accompanying report is now published and freely available in the repository Renate. In this blog article, we provide a short overview over the results.
About the study
We collected several thousand studies using search queries in Dimensions, Library, Information Science and Technology Abstracts (LISTA), Scopus and Web of Science and subsequently filtered them for relevance. The remaining empirical studies related to the effects of open access were expanded using the Open Access Tracking Project (OATP) and expert advice, resulting in the final corpus of 318 studies.
The effects examined are distributed over seven major fields:
- Attention in science
- Quality of scientific publications
- Knowledge transfer
- Productivity of the publication system
- Use of publications
- Inequality in the science system
- Economic effects on the publication system
We read the key studies in each of these fields in detail and contrasted each studies’ findings in a systematic comparison.
The state of research on the effects of open access
The empirical literature confirms several advantages of open access: free access results in increased use by a more diverse audience. Open access publications contribute more to knowledge transfer than research published behind paywalls. Furthermore, open access shortens the time of the publication process.
Our review of the state of research also shows that some concerns about open access have no empirical basis: there is no difference in quality of open access and non-open access publications, and the sales figures of print editions of books available in open access do not differ significantly from non-open-access titles.
The result on a possible citation advantage of open access publication may seem surprising: increased citations are often considered as an advantage of open access. The open access citation advantage is indeed confirmed by most empirical studies. However, a non-negligible fraction of the empirical literature comes to different conclusions. An open access citation advantage therefore cannot be considered as clearly empirically confirmed but it is certainly not refuted. Given the methodological difficulties in this field of research and the high degree of plausibility, an open access citation advantage can nonetheless be reasonably assumed.
Only one aspect of open-access publishing has negative effects: when authors are required to pay article processing charges (APCs) for open access publications, authors with fewer financial resources – due to low income in some regions of the world or a lack of institutional support – may be precluded from publishing. This effect, however, is not inherent to open access as such but only occurs with one business model of open-access publishing.
Further research is needed
While the empirical studies examined answer many questions about the effects of open access, we also identified research gaps. In almost all fields, further studies would be useful to verify existing results and to improve the generalizability of the findings. New studies that apply methods and research designs that systematically rule out potential confounding factors would be particularly helpful.
Relations between effects have been hardly studied, or not at all: how does the negative effect of APCs on inequality in the science system relate to the positive effect of open access on diversity in the use of scientific publications? How exactly does open access affect the career paths of scientists? Who benefits from open access – and are advantages distributed equally regardless of the researchers’ gender and access to financial resources? Further research on the effects of open access promises to provide valuable insights for the ongoing transformation of scholarly publishing to full open access.
Dr David Hopf is a philosopher of science with a long-standing interest in both epistemic and ethical problems related to the science system and its infrastructure. He currently works at the TIB publishing services, where he is contributing to a research project on the effects of Open Access.