Research ethicists are concerned about the growing ways in which scientists can falsify or manipulate the citation counts of their studies. Increasingly brazen practices have emerged in recent months. One method was revealed through a sting operation in which a group of researchers purchased 50 citations to inflate the Google Scholar profile of a fictional scientist they had created.

The scientists purchased the citations for $300 from a company that appears to bulk sell fake citations. This confirms the existence of a black market for fake credentials that research integrity sleuths have long speculated about, the team says.

“We started noticing several Google Scholar profiles with questionable citation histories,” says Yasir Zaki, a computer scientist at New York University (NYU) Abu Dhabi, whose team described the Sting operation in a February preprint. “When a manuscript receives hundreds of citations within a few days of publication, or when a scientist has a sudden and massive increase in citations, then you know something is wrong.”

These practices are concerning because many aspects of a researcher's career depend on how many references their work receives. Many institutions use citation counts to evaluate scientists, and the numbers inform metrics such as the h-index, which is intended to measure the productivity of scientists and the impact of their studies.

Citation manipulation can have real consequences. In June, Spanish newspaper El País reported that the country's Research Ethics Committee had asked the University of Salamanca to investigate the work of its newly appointed rector Juan Manuel Corchado, a computer scientist accused of artificially inflating his Google Scholar metrics.

References for sale

Research ethicists already suspected that citations in Paper mills are for sale, services that produce low-quality studies and sell authorships on already accepted papers, says Cyril Labbé, a computer scientist at the University of Grenoble Alpes in France. “Paper mills have the ability to include citations in the papers they sell,” he says.

In November 2023, Philadelphia, Pennsylvania-based analytics firm Clarivate excluded more than 1,000 researchers from its annual list of highly cited researchers due to fears of citation manipulation and 'hyper-publishing'.

In their sting operation, Zaki and his colleagues created a Google Scholar profile for a fictional scientist and uploaded 20 papers created using artificial intelligence.

The team then turned to a company they found while analyzing suspicious citations linked to one of the authors in their dataset that appeared to be selling citations to Google Scholar profiles. The study authors contacted the company by email and later communicated via WhatsApp. The company offered 50 citations for $300 or 100 citations for $500. The authors chose the first option and 40 days later, 50 citations from studies in 22 journals - 14 of which were in the Scopus-indexed scientific database - were added to the fictitious researcher profile on Google Scholar.

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