[2608.16322] Estimating global article processing charges paid to 14 publishers for open access between 2019 and 2025

This study presents estimates of the global expenditure on article processing charges (APCs) paid to 14 publishers for open access (OA) between 2019 and 2025. APCs are charged for publishing in fully OA journals (gold) and making individual articles OA in subscription journals (hybrid), but how much is paid, and for which articles, is not publicly known. We therefore curated an open dataset of publicly listed APC prices from 14 academic publishers (ACS, CUP, De Gruyter, EDP, Elsevier, Frontiers, IEEE, IOP, MDPI, OUP, PLOS, Sage, Springer Nature, and Wiley) and combined it with counts of OA articles from OpenAlex. We estimate that $15.08 billion (in 2025 USD) was spent globally on APCs between 2019 and 2025. Adjusted for inflation, annual spending quadrupled from $0.9 billion in 2019 to $3.7 billion in 2025, with >85% concentrated among a few large publishers. Hybrid OA fees exceed gold fees, and the median fee paid is higher than the median price listed for both. Our approach addresses major limitations in previous efforts to estimate APC spending, offering much-needed insight into an opaque aspect of scholarly publishing, especially as transformative agreements make it more challenging to understand the costs of publishing OA.