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 impact of these agreements on hybrid 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. Results suggest a strong growth in open access between 2018 and 2022 from 4.3% to 15%. During this period, 11,189 hybrid journals provided open access to 742,369 out of 8,146,958 articles, representing a five-year open access proportion of 9.1%. Authors who could make use of transformative agreements at the time of publication contributed 328,957 open access articles. In 2022, 143,615 out of 249,511 open access articles in hybrid journals or 58% were 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, the OECD and BRICS areas revealed different publication trends. In conclusion, this study suggests that current levels of implementation of transformative agreements is insufficient to bring about a large-scale transition to full open access.

翻译：围绕旨在推动期刊出版向完全开放获取转型的转型协议所引发的持续争议，凸显了开展大规模研究以评估这些协议对混合开放获取影响的必要性。通过整合来自cOAlition S期刊检查工具、Crossref及OpenAlex等多个公开数据源的数据，本研究提出了一种分析700余项协议的新方法。研究结果表明，2018年至2022年间，开放获取比例从4.3%显著增长至15%。在此期间，11,189种混合期刊在8,146,958篇文章中开放获取了742,369篇，五年开放获取占比为9.1%。在发表时能够利用转型协议的作者贡献了328,957篇开放获取文章。2022年，混合期刊中249,511篇开放获取文章中的143,615篇（即58%）是通过转型协议实现的。这一趋势主要由爱思唯尔、施普林格·自然及威立三家商业出版商推动，但各期刊、出版商、学科及国家所属地的开放获取采用率存在显著差异。特别是经合组织与金砖国家地区呈现出不同的发表趋势。综上所述，本研究认为当前转型协议的实施水平尚不足以实现大规模向完全开放获取的过渡。