An analysis of almost 200,000 peer reviews found that although less than 3% of academics regularly review studies for predatory journals, those who do are usually in the early stages of their academic career and based in developing countries. Writing these reviews is likely to have taken around 30,000 hours – time researchers wasted on studies with little to no scientific impact.

Predatory journals trick scholars into paying for publishing their work while not providing any of the editorial services of legitimate publications. Studies appearing in such journals have little impact and are rarely cited.

The predatory journals that offer peer review – some accept any and all manuscripts without review – do little more than waste reviewers’ resources. Peer reviewing, an essential gatekeeping mechanism for scientific soundness, takes a lot of time – around five hours per review. But when reviewers flag up problems in manuscripts submitted to predatory journals, they are often ignored and studies are simply accepted.

In a first-of-its-kind study, Anna Severin and her team at the Swiss National Science Foundation and at Publons – a database where academics can record their reviewing activities – have now investigated who reviews for predatory titles. They found that the scholars hardest hit by predatory reviewing practices are junior researchers with few publications. Many are working in low-income countries in Sub-Saharan Africa, North Africa and South Asia.

Severin and co-workers investigated over 183,700 reviews by 19,600 reviewers. First, they randomly selected 1000 predatory and 1000 legitimate journals from lists provided by Cabell’s Scholarly Analytics. They then matched the journals’ names with reviews logged in Publons. Finally, for academics with matched journals, the team created a network of other journals they reviewed for, which they compared back to Cabell’s lists.

The study notes that early-career researchers, particularly those in marginalised communities, might be more likely to become victims of predatory practices thanks to publishing pressures in academia. A possible explanation for the abundance of reviews for predatory titles from developing countries is that these journals have become part of the workflow in those regions, Severin and colleagues write. Previous analyses found many authors and editors of predatory journals were based in the same countries.

Nevertheless, the overall number of researchers who review regularly (26–75% of their Publons-logged reviews) or almost exclusively (more than 76% of their reviews) for predatory titles remains small, only 1.9% and 0.4%, respectively. 90% of the researchers in the Publons database sample have never reviewed for a predatory journal.

Severin and colleagues appeal to research institutions, funders and publishers to increase training and monitoring to not only prevent publishing but also reviewing for predatory journals.