The world’s most-cited researchers, according to newly released data, are a curiously eclectic bunch. Nobel laureates and eminent polymaths rub shoulders with less familiar names, such as Sundarapandian Vaidyanathan from Chennai in India. What leaps out about Vaidyanathan and hundreds of other researchers is that many of the citations to their work come from their own papers, or from those of their co-authors.
Vaidyanathan, a computer scientist at the Vel Tech R&D Institute of Technology, a privately run institute, is an extreme example: he has received 94% of his citations from himself or his co-authors up to 2017, according to a study in PLoS Biology this month1. He is not alone. The data set, which lists around 100,000 researchers, shows that at least 250 scientists have amassed more than 50% of their citations from themselves or their co-authors, while the median self-citation rate is 12.7%.
The study could help to flag potential extreme self-promoters, and possibly ‘citation farms’, in which clusters of scientists massively cite each other, say the researchers. “I think that self-citation farms are far more common than we believe,” says John Ioannidis, a physician at Stanford University in California who specializes in meta-science — the study of how science is done — and who led the work. “Those with greater than 25% self-citation are not necessarily engaging in unethical behaviour, but closer scrutiny may be needed,” he says.
The data are by far the largest collection of self-citation metrics ever published. And they arrive at a time when funding agencies, journals and others are focusing more on the potential problems caused by excessive self-citation. In July, the Committee on Publication Ethics (COPE), a publisher-advisory body in London, highlighted extreme self-citation as one of the main forms of citation manipulation. This issue fits into broader concerns about an over-reliance on citation metrics for making decisions about hiring, promotions and research funding.
This is not a surprise.
If fraud can occur, fraud will occur.