Clarivate to stop counting citations to retracted articles in journals’ impact factors

Clarivate will no longer include citations to and from retracted papers when calculating journal impact factors, the company announced today. 

The change comes after some have wondered over the years whether citations to retracted papers should count toward a journal’s impact factor, a controversial yet closely watched metric that measures how often others cite papers from that journal. For many institutions, impact factors have become a proxy for the importance of their faculty’s research.

Retractions are relatively rare and represent only 0.04% of papers indexed in Clarivate’s Web of Science, according to the announcement. But the overall retraction rate has risen recently, to about 0.2%, which, along with a decrease in the time it takes to retract papers, motivated the policy change. Nandita Quaderi, the editor-in-chief of Web of Science, said in the announcement the policy would “pre-emptively guard against any such time that citations to and from retracted content could contribute to widespread distortions in the [journal impact factor].”

Clarivate publishes impact factors annually in its Journal Citation Reports. The impact factor represents the number of citations in a given year to works published in a journal in the previous two years, divided by the total number of citable items published in those previous two years. 

Starting with the 2025 Journal Citation Reports, Clarivate will exclude citations to and from retracted articles in the numerator, “ensuring that citations from retracted articles do not contribute to the numerical value of” the impact factor, the announcement stated. Retracted articles will remain in the article count for the denominator, “maintaining transparency and accountability.” 

“This decision makes intuitive sense but could incentivize against retraction,” bibliometrics expert Reese Richardson said. By keeping retracted items in the denominator of the equation, “this deepens the impact that any given retraction will have on a journal’s [impact factor],” he told us. He said he also wonders “how many journals will actually see a substantial reduction” in impact factor as a result of the change. 

Quaderi told us Clarivate would stop counting citations once the paper is retracted, but would keep those that occurred before. The company will continue to use the Retraction Watch Database to flag retracted papers in indexed journals, which it has done since 2022.

Clarivate typically releases the annual Journal Citation Reports in late June. The JCR incorporates information from impact factors to assess the overall standing of its indexed journals. The company also suppresses impact factors for journals with abnormal citation behaviors. 

Quaderi told us this change would not impact a researcher’s h-index, another metric that measures citation behavior and productivity. In other words, when Clarivate calculates h-index, it won’t remove retracted papers – or citations to those papers – from the calculation. 

In 2011, Arturo Casadevall and Ferric Fang, who is now a member of our parent nonprofit’s board of directors, showed using the Retraction Index that journals with higher impact factors tended to have more retractions, for unclear reasons.

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