### **Long Description: Trends in Publisher Affiliation Data (2020–2025)** **Chart Overview** This dataset tracks the number of publications with affiliation data indexed in OpenAlex for 15 major academic publishers. The data spans from 2020 through the incomplete year of 2025. The publishers are visually categorized into three groups based on their data stability: 1. **Green:** Publishers that deposit affiliation data into Crossref (Stable). 2. **Red:** Publishers showing a significant decline in OpenAlex coverage. 3. **Orange:** "At Risk" publishers that do not deposit to Crossref and rely on web crawling. **Key Trend 1: The 2024 Decline (Red & Orange Categories)** A major divergence appears in 2024, where several publishers show a sharp drop in indexed affiliation data compared to their 2023 peaks: * **Springer Nature** shows the steepest decline, dropping from **145,872** records in 2023 to **50,844** in 2024. * **Elsevier BV** falls significantly from **493,433** (2023) to **319,147** (2024). * **IOP Publishing** continues a downward trend, reaching a low of **22,709** in 2024. **Key Trend 2: Stability in Crossref Publishers (Green Category)** Publishers that actively deposit data to Crossref generally maintained or increased their coverage in 2024: * **Wiley** remained stable (114,658). * **MDPI** remained robust (113,806), though slightly down from its 2023 peak. * **IEEE** and **American Institute of Physics (AIP)** showed growth, with IEEE rising to **70,238** and AIP reaching **21,901**.