Each year, the Journal Citation Reports™ (JCR) release provides a summary of the network of scholarly citations from the prior year of Web of Science™ coverage. It is a snapshot of the continually evolving research landscape.
“It’s tough to make predictions, especially about the future.”
As we approach this year’s JCR release at the end of this month, we reviewed factors that may affect the published metrics. This year’s data summarizes Web of Science™ citations from 2021, including 35,000 publications (journals, books and conference proceedings), 2.7 million citable items and 145 million cited references indexed in the Web of Science Core Collection™.
Two novel events drove the 2020 data: the inclusion of Early Access content in the JCR for the first time, and the sudden appearance of COVID-19 as an entirely new, extremely urgent field of study. These factors made the 2020 data explored in last year’s release particularly unusual. More journals increased in Journal Impact Factor (JIF) from 2019 to 2020 than in any other year-to-year interval across the last decade (see Figure 1).
Analysis of the factors that created these striking changes showed that Early Access content contributed roughly 10% of the JIF citations. The remainder of the effect was traceable to a generalized increase in the volume of content published in 2020. The 2021 JCR contained over 25% more articles and citations than the prior year. These were not just articles about COVID-19, but the intensity of the research effort in the face of this global crisis was broadly observed by researchers in information science (for example: here, and here).
We wondered: will we see a ‘return to normal’ after the unprecedented changes in the 2020 data? Or will we continue to see new effects coming from the influx of COVID-19 research and the inclusion of Early Access content in JCR metric calculations?
First, let’s define how we count Early Access content. For indexing in Web of Science, Early Access is defined as ‘Version of Record’ content that is published online prior to final assignment in a completed volume/issue. Although we had been receiving this content from an increasing number of journals and publishers since 2017, we announced in 2020 that following year’s JCR release would be the first to include Early Access according to the date of earliest publication. We took a prospective approach, including each new year of Early Access content from 2020 forward, even while we continue to expand the number of participating publishers and journals. A rapid incorporation of new published works ensures the JCR will accurately reflect how researchers are using the literature. The prospective approach meant that Early Access was a new source of citations into the JIF numerators last year, which contributed to the generalized increase in Journal Impact Factors (JIFs) across the whole JCR.
What might this mean for the 2022 Journal Citation Reports?
This year, there are three major influences at work in some, or all, of the journals reviewed:
- For the first time Early Access content will be incorporated into the count of citable items, the denominator of the Journal Impact Factor (JIF)
- In addition, the continued expansion of Early Access content throughout 2021 provides another increase in the number citing materials in the numerator of the JIF
- COVID-19 continues to influence every aspect of scholarly publishing, just as it has affected every aspect of society
Let’s examine this in more detail.
For the first time Early Access content from the 2020 data will be incorporated into the denominator of the Journal Impact Factor (JIF), the number of citable items
In the 2021 JCR release, content published as a Version of Record in 2020 was included as part of the 2020 citing corpus for the calculation of metrics. This shift of timing increased the total volume of 2020 citing content by over 180,000 items (approximately 11% of the 2020 citing content), contributing 1.2 million references to 2019 or 2020 (less than 10% of the total citation count to those years). Most of these items have now been incorporated into an issue, either in 2021 or 2022, but they have already been counted as part of the 2020 content. For journals that have been providing Early Access content, the additional items processed in 2020 as Early Access will now be included as part of the denominator of the JIF for 2021. Depending on the relative volume of Early Access content, this may decrease their Journal Impact Factor relative to last year.
In addition, the continued expansion of Early Access content will provide an increased number of 2021 citing materials in the numerator of the JIF
Processing Early Access content according to their earliest Version of Record date increases the number of citations they contribute to the JIF numerator, and the effects are broadly distributed across journals. Throughout 2021, we continued to expand the journals and published providing Early Access content. From 2020 to 2021, the volume of Early Access content increased by 56%. More than 330,000 Early Access citing items containing nearly 3 million references to 2019 or 2020 are included in the JCR metrics in this year’s release.
This leaves us with competing influences: 2020 Early Access content in the denominator and additional Early Access content in 2021 contributing to the numerator. One effect which may decrease JIFs, the other which may increase them.
Looking at the year-to-year changes in JIF from 2010 to 2021 (see Figure 1) highlights how unusual the 2020 data were in the context of both prior year, and of the coming year. From 2019 to 2020, over 80% of journals showed an increase in JIF. Across the prior decade, an average of just 55% of journals showed an increase or no change to their JIF from the prior year. The 66% of journals having an increased JIF from 2020 to 2021 is above average, but not without precedent.
Figure 1: Comparison of JIF across each year-to-year interval from 2010 through 2021.
Green bars show the percentage of journals with no change or an increase in JIF; purple, downward bars show the percentage of journals that decreased in JIF.
Among the journals with an increased JIF, the relative size of these increases was also more moderate than last year. But there are notable exceptions – journals that demonstrate astonishing increases in JIF.
COVID-19 continues to influence every aspect of scholarly publishing, just as it has affected every aspect of society
To explore the reasons that may lie behind journals with high increases in their JIFs, we identified 10,100 journals with a 2021 JIF over 2.000 and focused on journals showing a JIF at least double in value compared to 2019. This cut the number of journals to 222, of which 105 were in a small number of categories in general medicine, critical care, public health, infectious diseases, immunology and basic biomedical sciences. Some journals in these areas show JIFs 10 times higher than they have had before.
Extracting the top-cited articles from journals outside areas of medicine and biomedical research showed that most – but not all – journals had one or more highly cited articles dealing with many aspects of the COVID-19 global crisis – from the influence of lockdowns on measures of social/economic inequality, to how disruptions in the supply chain affected agriculture. The JCR, collecting and summarizing this changed literature, also reflects these large disruptions and continues to offer a unique window into the evolution of research.
A crisis on the scale of global pandemic affected every part of life, in every part of the world. COVID-19 and the ramifications of its spread were entirely novel topics of study and have changed the landscape of scholarly publishing. The massive and rapid response of the scholarly community to COVID-19 extends far beyond medical care or medical sciences, and its ripples will continue for years, or decades.
This underscores the breadth and the importance of SDG 3: Health and wellbeing as a critical aspect of the UN Sustainable Development Goals, which Clarivate is fully committed to. Working with our customers, we are proud to be part of the global research community working together towards a sustainable world, learning from the COVID-19 pandemic, and showcasing the vital links between research as demonstrated in the Web of Science.
Journal Citation Reports can help you understand key citation impact trends to inform your publishing strategy. Learn more here.
 Journals with JIFs below 2.0 show exaggerated effects on percentage change in JIF arising from relatively small changes in citation rate, so they were excluded.