Over the last two decades, research funders have adopted Open Access (OA) mandates, with various forms and success. While some funders emphasize gold OA through article processing charges, others favour green OA and repositories, leading to a fragmented policy landscape. Compliance with these mandates depends on several factors, including disciplinary field, monitoring, and availability of repository infrastructure. Based on 5 million papers supported by 36 funders from 20 countries, 11 million papers funded by other organisations, and 10 million papers without any funding reported, this study explores how different policies influence the adoption of OA. Findings indicate a sustained growth in OA overall, especially hybrid and gold OA, and that funded papers are more likely to be OA than unfunded papers. Those results suggest that policies such as Plan S, as well as read-and-publish agreements, have had a strong influence on OA adoption, especially among European funders. However, the global low uptake of Diamond OA and limited indexing of OA outputs in Latin American countries highlight ongoing disparities, influenced by funding constraints, journal visibility, and regional infrastructure challenges.

翻译：过去二十年间，研究资助机构纷纷推行开放获取（OA）强制政策，其形式与成效各异。部分资助机构侧重通过文章处理费实现金色OA，另一些机构则偏好绿色OA及存储库模式，造成政策布局碎片化。对这些强制政策的遵循程度受制于学科领域、监测机制及存储库基础设施可用性等多重因素。本研究基于来自20个国家36家资助机构支持的500万篇论文、其他机构资助的1100万篇论文，以及未标注任何资助来源的1000万篇论文，探讨不同政策如何影响OA的采纳。结果表明，OA整体呈持续增长态势，尤以混合型与金色OA为甚，且受资助论文的OA采纳率高于未资助论文。这些发现表明，Plan S等政策以及阅读-出版协议对OA采纳产生了显著影响，尤其在欧洲资助机构中。然而，全球钻石OA的低普及率以及拉丁美洲国家OA成果索引的有限性，凸显出资助限制、期刊可见度与区域基础设施挑战所导致的持续差异。