In research, a paper mill is a business that publishes poor quality or completely fraudulent journal papers that seem to resemble genuine research, as well as sells authorship on such papers.^[1][2]

Paper mills are an example of academic dishonesty that affects all fields of academic publishing including academic writing, scientific writing and medical writing, and represents a failure of research ethics and research integrity.

In some cases, paper mills are sophisticated operations that sell authorship positions on legitimate (but poor quality) research, but in many cases the papers contain fraudulent data and can be heavily plagiarized or otherwise unprofessional.^[3][4]

Activities include contract cheating. academic ghostwriting and medical ghostwriting. It may include data fabrication, leading to junk science and retractions in academic literature.

In 2014 COPE wrote an editorial raising concerns on agencies selling services, including authorship of pre-written manuscripts.^[5]

According to a 2021 report in Nature, thousands of papers in academic journals had been traced to paper mills from China, Iran and Russia, and some journals were revamping their review processes."^[3] Chinese researchers have been identified as particularly prevalent customers of paper mill services.^[6] Differing estimates put the share of paper mill productions between 2% and 20% of published academic papers, with particularly severe problems in some areas of biomedicine.^[2][6][7] The apparent prevalence of paper mills in China has been attributed to the heightened "publish or perish" pressure placed on academics and other scientific professionals in China.^[8]

A 2024 peer-reviewed forensic study showed that provenance-based image analysis can automatically cluster manuscripts that originate from the same paper mill, providing scalable evidence of systematic production.^[9]

In early 2022, Times Higher Education and the Science Magazine News department covered a report exposing a Russian paper mill company International Publisher Ltd.^[4][11] The report identified hundreds of published academic papers where positions for authorship had been sold through a Russian website allowing researchers to pay for academic prestige without requiring legitimate research contributions.^[10][12] During the three-year period analyzed, 419 articles were identified that were matched to manuscripts later published in many different academic journals, with a significant bias towards publications in predatory journals.^[10] While the paper mill targeted various journals, almost 100 papers were published in International Journal of Emerging Technologies in Learning (Kassel University Press) alone, seemingly coordinated through the involvement of journal editors hosting Special Issues with space for coauthors auctioned off for anywhere from $180–5000 USD. In a separate network, guest editors and salaried academic editors for MDPI were found to coordinate sale of authorship across four different MDPI journals, totalling over 20 papers (picture, right).^[10] Beyond collusion between editors and International Publisher Ltd., many legitimate research papers also sold authorship unknown to the journal editors, and were ultimately accepted in journals published by Elsevier, Oxford University Press, Springer Nature, Taylor & Francis, Wolters Kluwer, and Wiley-Blackwell. As of April 6, 2022, many of these publishers have opened an investigation into the matter.^[4]

In May 2024, the Wall Street Journal published a report on fake studies that affected New Jersey publisher Wiley. More than 11,300 papers were retracted, and 19 journals were reportedly closed. The problematic papers were linked to Hindawi, an Egyptian publisher of about 250 scientific journals that Wiley acquired in 2021.^[13][14] The article detailed how the research paper mill fraud worked, and highlighted individual efforts to identify and prevent future fraud. The article also warned that artificial intelligence was going to make fraud more difficult to detect.^[13]

By analysing duplicated images, Richardson et al hypothesize that paper mills may have used a large bank of images for mass publications and may have collaborated with editors in targeted journals such as PLOS ONE and Hindawi for expedited publications. Paper mills can switch journals quickly if a partner journals get deindexed from literature aggregators. The researchers cited "Academic Research and Development Association" (ARDA), based in Chennai, India, as an example of such a paper mill.^[15]

While the overall prevalence of paper mill publications on biology and medicine is reported to be about 3%, a recent report^[16] used artificial intelligence to scan 2,647,471 publications on cancer research (particularly molecular oncology) published between 1999 and 2024. The study included papers classified as a "journal article" but excluded other publication types such as literature reviews and clinical trials. The study flagged 261,245 of these publications as being research paper mill publications (9.87%, 95% confidence interval 9.83 to 9.90). The number of such publications tended to steadily increase each year from 1999 to 2024 (e.g. percentage of paper mill publications in the cited cancers, 0.06% in 1999 and 14.4% in 2024). Among 25 countries (as defined by that of the first author named in the paper), the percentage of reports were from China 35.7%, Iran 20%, Saudi Arabia 15.6%, Egypt 15.2%, Pakistan 13.4%, Malaysia 13.2%, Taiwan 9.2%, India 9.1%, Turkey 8.9%, Thailand 8.8%, South Korea 8.2%, Mexico 5.8%, Russia 5.5%, Poland 5.2%, Brazil 4.4%, Japan 4.2%, Greece 3.2%, Italy 2.9%, Spain 2.5%, Germany 1.9%, United States 1.7%, Australia 1.6%, Canada 1.4%, France 1.2%, and the United Kingdom 0.9%. The flagged papers were overrepresented in basic research and in gastric, bone, and liver cancers. Among all cancer types, gastric cancer papers were 22% of flagged papers, bone cancer papers such as osteosarcomas were 21% of flagged papers, and liver cancer papers were 20% of flagged papers. Breast, skin, prostate, and blood cancers had the lowest percentages of flagged papers, falling within a range of 10-15% of the flagged papers.

• Academic mill (disambiguation)
• Diploma mill
• Essay mill
• Research Integrity Risk Index
• Predatory publishing
• Publish or perish