Clarivate released its annual Highly Cited Researchers list

On 16 November 2021, Clarivate plc nveiled its 2021 list of Highly Cited Researchers today. The methodology that determines the “who’s who” of influential researchers draws on the data and analysis performed by bibliometric experts and data scientists at the Institute for Scientific Information at Clarivate.

The annual list identifies some 6,600 researchers from across the globe who demonstrated significant influence in their chosen field or fields through the publication of multiple highly cited papers during the last decade. The Highly Cited Researchers’ names are drawn from the publications that rank in the top 1% by citations for field and publication year in the Web of Science citation index, and the list identifies the research institutions and countries where they are based.

The key findings for 2021 show:

• 6,602 researchers from more than 70 countries and regionshave been recognized this year – 3,774 in specific fields and 2,828 for cross-field impact.
• The United Statesis the institutional home for 2,622 of the Highly Cited Researchers in 2021, which amounts to 39.7%, down from 43.3% in 2018. While there has been a decline in the number of U.S.-based Highly Cited Researchers, there can be no doubt that the U.S. still leads the world in research influence. Of all papers indexed in the Web of Science for 2010 to 2020 the percentage with a U.S.-based author was 24.7%.
• Mainland Chinais second this year, with 935 Highly Cited Researchers, or 14.2%, up from 7.9% in 2018. In four years, Mainland China has nearly doubled its share of the Highly Cited Researchers population.
• The United Kingdom, with 492 researchers or 7.5%, comes in third. This is a particularly high number of researchers at the very top of their fields in terms of citation impact, given that the United Kingdom has a population 1/5 the size of the United States and 1/20 the size of Mainland China.
• Australiahas narrowly overtaken Germany at fourth, with 332 researchers, and the Netherlands is sixth, with 207 researchers – remarkable for countries of 25 million and 17 million, respectively, versus Germany’s 83 million. They also place above Canada, France, Spain and Switzerland in the top 10.
• Harvard University, home to 214 researchers, is once again the institution with the highest concentration of Highly Cited Researchers in the world.
• Hong Konghas increased its number to 79 from 60 last year, an impressive achievement, partly due to a dramatic increase in Highly Cited Researchers from the University of Hong Kong, which more than doubled its number of Highly Cited Researchers from 14 to 33 from 2020 to 2021.
• For the first time, researchers from Bangladesh, Kuwait, Mauritius, Moroccoand the Republic of Georgia are included on the list this year.

Naturally, Mainland China’s gain means losses elsewhere. There is a 1.8% loss in Highly Cited Researchers for the United States since last year and 3.6% since 2018. This contrasts with an increase of 6.3% for Mainland China since 2018. The United Kingdom exhibits a decline of .5% since last year and 1.5% since 2018. Germany has lost .9% share since 2018.

Nobel Prize recipients and researchers of Nobel quality

This year’s list includes 24 Nobel laureates, including five announced this year: David Julius, University of California San Francisco, San Francisco, CA, United States (Physiology or Medicine); Ardem Patapoutian, Scripps Research, La Jolla, CA, United States (Physiology or Medicine); David W. C. MacMillan, Princeton University, Princeton, NJ, United States (Chemistry); David Card, University of California Berkeley, Berkeley, CA, United States (Economics); and, Guido Imbens, Stanford University, Stanford, CA, United States (Economics). Also included are 77 Citation Laureates™: individuals recognized by Clarivate, through citation analysis, as ‘of Nobel class’ and potential Nobel Prize recipients.

Exceptional broad performance
Of the researchers named as Highly Cited in the 21 Essential Science Indicators (ESI)™ fields, 23 researchers showed exceptionally broad performance, recognized for being highly cited in three or more fields. They are a truly global group – in North America, Europe, Asia and the Middle East. Professor Rob Knight from the University of San Diego California was alone in being named for four ESI fields (Biology and Biochemistry; Environment/Ecology; Microbiology; Molecular Biology and Genetics).

Figure 1: Highly Cited Researchers by country or region

Figure 2: Highly Cited Researchers by research institution or organization

The full 2021 Highly Cited Researchers list and executive summary can be found here.

Methodology:
More than 6,600 researchers, in 21 fields of the sciences and social sciences, and cross-field categories were selected based on the number of highly cited papers they produced over an 11-year period from January 2010 to December 2020. The methodology that determines the who’s who of researchers draws on data and analysis performed by bibliometric experts at the Institute for Scientific Information at Clarivate. It uses InCites Benchmarking & Analytics™, Essential Science Indicators™ and a unique compilation of science performance metrics and trend data based on scholarly paper publication counts and citation data from the Web of Science™, the world’s largest publisher-neutral citation index and research intelligence platform.

The sharp decline of .7% for Switzerland since 2018 is anomalous and reflects a change in our methodology: Papers with more than 30 institutional addresses were removed from our analysis in past years, but this year we eliminated papers with more than 30 authors or group authorship. The change, which we judged an improvement in reasonably crediting individual authors – the previous use of institutional addresses was a heuristic – happened to impact Switzerland heavily and especially researchers at the Swiss Institute of Bioinformatics, which produces a significant number of highly cited papers with many authors but few institutional addresses.