Toward transparency of hybrid open access through publisher?provided metadata: An article?level study of Elsevier

With the growth of open access (OA), financial flows in scholarly journal publishing have become increasingly complex, but comprehensive data on and transparency these are still lacking. The opacity is especially concerning for hybrid OA, where subscription-based journals publish individual articles as OA if an optional fee paid. This study addresses lack by leveraging Elsevier article metadata provides first publisher-level uptake invoicing. Our results show that Elsevier's has grown steadily slowly from 2015 to 2019, doubling number published per year increasing share 2.6 3.7% all articles. Further, we find most were invoiced directly authors, followed through agreements with research funders, institutions, or consortia, only a few funding bodies driving uptake. As such, our findings point role policies publishing. further demonstrate value publisher-provided improve