Precautions About Self-citation and Grey Literature

It’s natural that researchers will want to cite their previous works, especially when writing about a topic that draws upon conclusions they formerly established. This is called self-citation. Though it’s an acceptable practice in moderation, some scientists are taking advantage of the notoriety and prominence that come with high citation metrics by indulging in excessive self-citation.

The research community is grappling with the question of when self-citation crosses the threshold from normal to excessive and what we can do about this problem.

The recent publication of a PLoS Biology study shows more than 250 scientists with more than 50% of all of their citations coming from themselves or their co-authors. When compared to the median self-citation rate of 12.7%, the academic and research communities have had to parse the significance of these findings.

Some say excessive self-citation diminishes an author’s credibility and is used as a tactic to “game the system” and overblow one’s own impact. Others believe it’s entirely irrelevant or even justifiable.

So, where do we stand? What do we make of self-citation?

As with most things in life, we don’t see this issue in black and white – we see it as grey. We want to take a measured approach, consider the context, and then use this knowledge to think critically and make informed decisions.

Legitimate Reasons for Self-citation

There are certainly cases where self-citation is warranted. For instance, in particle physics and astronomy, most papers have hundreds or even thousands of co-authors, if you can believe that. In this case, it’s virtually impossible to avoid high rates of self-citation because such a large portion of the field contributes to any given paper.


Source: Nature

Nature also finds that early-career scientists generally have higher self-citation rates, as well. While this may seem counterintuitive, as older, more experienced researchers have a greater corpus of work to reference, they also have had more time to collect citations from other researchers.

youth effect

Source: Nature

Ultimately, some self-citation is simply necessary. Science always builds upon itself, and it’s not uncommon for researchers to devote an entire career to a single investigation. It’s natural, therefore, for some scientists to draw from previous works to inform future papers.

The Danger of Excessive Self-citation

There is another side of the coin. Take, for example, Sundarapandian Vaidyanathan, a computer scientist from Chennai, India. Up to 2017, he had received an outstanding 94% of all citations from himself or his co-authors. As a result, he was rewarded with a 20,000 rupee (US $280) award by the Indian government for being one of his country’s top scientists, as measured by citation metrics and productivity.

Self-citation can bring other benefits, as well. “The author who manages to fit in even one more self-citation per article will be much better off years down the road than her colleague who didn’t,” reports Scientific American. “The effect turns negative only in very high levels of self-citations (40-50 a year). It seems that self-citation makes authors more visible.” And who doesn’t want that?

The incentives for authors to self-cite more frequently—whether or not such citations are justified—are tangible and potentially long-lasting. So long as there are systems in place that reward scientists for accruing greater numbers of citations, whether it takes the form of government funding, greater publicity, or university policies, there will always be those who want to game the system to get ahead.

The most pressing concern is assessing the actual worth of the research itself. When we measure a researcher’s success by their citation numbers, we find that publications from authors who employ excessive self-citation gain a disproportionate amount of attention, compared to comparable authors who don’t do so. Thus, rather than greater visibility stemming from their work’s impact, it comes from an arbitrary metric that they themselves can create.

This obviously leads to representation issues, both on a localized and global scale. Colleagues who engage in such practices are more likely to be lauded by their communities—and receive funding for their projects—than those who only self-cite moderately. Similarly, some nations come to be viewed as more important by the international community. The data shows that Ukraine and Russia have average self-citation rates much higher than the median rate.

by country

Source: Nature

Addressing the Issue

When we look at both sides of the issue, we see that self-citation certainly has a place in the scientific community, but we also need to be wary of excessive self-citation as an exploitative tactic. In our next post, we’ll discuss ways to address this issue.