Social-science preprints top the fake-citation charts in a 2025 audit

A large audit of 2.5 million papers and 111 million references across arXiv, bioRxiv, SSRN and PubMed Central found 146,932 hallucinated citations in 2025 papers; SSRN had the highest rate at 1.91%, with arXiv 0.39%, PubMed Central 0.27%, and bioRxiv 0.21%. Hallucinations are more common among authors with little pre-2022 publication history and often disproportionately credit established male researchers; the findings come from a non-peer-reviewed arXiv preprint and highlight the need for safeguards to curb these errors.