Predatory Journals Grew from 10,000 to Over 18,000 in a Decade, Publishing 420,000+ Articles Per Year That Pollute the Scientific Record

The number of predatory journals has nearly doubled from roughly 10,000 in 2015 to over 18,000 by late 2024, collectively publishing hundreds of thousands of articles annually with little or no genuine peer review. Only 7.35% of solicitation emails from these journals are even relevant to the recipient's research field. Why it matters: researchers in low-income countries disproportionately publish in and review for predatory journals without realizing it, so their work becomes invisible to legitimate citation databases and hiring committees, so the global south's scientific contributions are systematically devalued, so international research collaborations exclude researchers from these regions, so the knowledge gap between wealthy and developing nations widens rather than closes despite rising global research output. The structural root cause is that the open-access gold model (author-pays) created a business model where any entity can launch a journal and collect article processing charges without providing editorial services, while there is no global regulatory body that can shut down fraudulent journals, and researchers under publish-or-perish pressure are vulnerable to the promise of fast, guaranteed publication.