The ongoing controversy surrounding transformative agreements, which aim to transition journal publishing to full open access, highlight the need for large-scale studies assessing the uptake of open access in hybrid journals. This includes evaluating the extent to which transformative agreements enabled open access. By combining publicly available data from various sources, including cOAlition S Journal Checker, Crossref, and OpenAlex, this study presents a novel approach that analyses over 700 agreements and nine million journal articles published in more than 11.000 hybrid journals. Estimates suggest a strong growth in open access between 2018 and 2022 from 4.3% to 15%. In 2022, 58% of hybrid open access was enabled by transformative agreements. This trend was largely driven by the three commercial publishers Elsevier, Springer Nature, and Wiley, but the open access uptake varied substantially across journals, publishers, disciplines, and country affiliations. In particular, comparing the developments in the OECD and BRICS areas revealed different publication trends relative to hybrid open access. In conclusion, estimates suggest that current levels of implementation of transformative agreements is insufficient to bring about a large-scale transition to full open access.

翻译：围绕旨在将期刊出版转变为完全开放获取的转型协议的持续争议，凸显了评估混合期刊中开放获取采用情况的大规模研究的必要性，包括评估转型协议在多大程度上实现了开放获取。通过结合来自多个来源的公开数据，包括cOAlition S期刊检查器、Crossref和OpenAlex，本研究提出了一种新方法，分析了超过700项协议和九百万篇发表在11,000多种混合期刊上的期刊文章。估计显示，2018年至2022年间，开放获取比例从4.3%强劲增长至15%。2022年，58%的混合开放获取由转型协议促成。这一趋势主要由三家商业出版商——爱思唯尔、施普林格·自然和威立推动，但不同期刊、出版商、学科和国家所属领域的开放获取采用情况差异显著。特别是，比较OECD和BRICS地区的发展态势揭示了与混合开放获取相关的不同出版趋势。总之，估计表明，目前转型协议的实施水平不足以实现向完全开放获取的大规模转型。