In 2015, there were barely a dozen biomedical journals that each published more than 2,000 studies per year, representing 6% of total production between them. There are now 55 of these so-called “mega-journals” — together, they publish almost a quarter of all specialized literature, according to recent research by John Ioannidis.

Half of the top mega-journals come from the same publisher: MDPI, a corporate giant founded in Basel, Switzerland, by Chinese chemist Shu-Kun Lin. It currently controls 427 journals. Its top publication — International Journal of Environmental Research and Public Health — publishes nearly 17,000 studies each year, a number that makes it difficult to ensure quality. This journal charges authors more than $2,500 for the publication costs of each work. Five years ago, more than a dozen publishers of Nutrients — another one of these mega-journals — resigned, alleging that MDPI pressured them to accept low-quality studies and increase revenue. The work by meat expert José Manuel Lorenzo on gum disease was published in the journal Antioxidants — also owned by MDPI.

Shu-Kun Lin’s publishing house has become an empire in a short time. MDPI journals offer an easy way to publish studies, thanks to their less-demanding requirements. A scientist can submit a paper to them and see it published in as little as a month after a cursory review, instead of the typical six months that other publishers require. Emilio Delgado — professor of Research Methodology at the University of Granada in Spain — makes a devastating diagnosis about this situation: “The MDPI journals have engulfed the system.”

Delgado jokes that, in the academic world, there is already talk of “MDPI professors,” which refers to those who have risen thanks to CVs based on this type of shoddy work. He notes that Spanish universities have become veritable “factory farms” for insubstantial studies. Delgado and his colleague Alberto Martín have analyzed this change in the behavior of Spanish scientists. Their data shows that, in 2015, barely 0.9% of Spanish production was published in MDPI journals, compared to a 0.6% rate worldwide. Six years later, the percentage in Spain shot up to nearly 15% — double the proportion in the rest of the world. Some universities focus on getting their studies published in MDPI journals, such as the Catholic University of Ávila (71%), Alfonso X el Sabio University (42%), the University of Extremadura (30%) and the Catholic University of Murcia (27%). At the most prestigious university in Spain — the Complutense University of Madrid — the percentage exceeds 12%.