World’s 6,600 top cited researchers – China continues to grow

The big story of last month’s global ranking of Highly Cited Researchers was the rise of China, with 935 out of the list of 6,602 researchers, although America still dominates. Then there are the interesting outliers – such as Dr Arridina Susan Silitonga of Indonesia – who produce outstanding science outside of the support of massive research systems.

The Highly Cited Researchers’ list is produced by bibliometric experts and data scientists at the Institute for Scientific Information at Clarivate Plc in London. The 2021 ‘who’s who’ lists influential researchers from 70 countries or regions, but 82.9% are from 10 leading research countries and 71.4% from the top five, “a remarkable concentration of top talent”.

The list identifies researchers who demonstrate significant influence in their fields by having published multiple highly cited papers during the last decade. This year 3,774 of the researchers have been recognised in in specific fields and 2,828 for cross-field impact.

The researchers are drawn from publications that rank in the top 1% by citations for field and publication year in the Web of Science™, and the list identifies the institutions and countries where they are based. The researchers work in 21 fields of the sciences and social sciences, and cross-fields.

The country ranking

China, with 935 highly cited researchers, nearly doubled the country’s share of Highly Cited Researchers in three years, from 7.9% in 2018 to 14.2% this year. It has the second highest number of highly cited researchers. Consequently, the share of top researchers from Europe and North America declined.

In first place, the United States is still way ahead of the pack with 2,622 researchers. However, its share is down – from 55% in 2014 to 43.3% in 2018 and 39.7% in 2021. “Of all papers indexed in the Web of Science for 2010 to 2020, the percentage with a US-based author was 24.7%,” said Clarivate in a statement released on 16 November.

David Pendlebury, senior citation analyst at the Institute for Scientific Information, said that particularly when looking over the past four years, sizeable gains for mainland China and a decline for the US “reflect a transformational rebalancing of scientific and scholarly contributions at the top level through the globalisation of the research enterprise”.

The United Kingdom has the third highest numbers of much-cited researchers, with 492 of the world’s most cited scientists or 7.5% of the share, which has slipped down by 1.5% from 2018 to 2021.

In fourth position is Australia with 332 researchers, or 5%, which is up by 1%. It overtook Germany, which is now fifth with 331 researchers or 5%, down nearly 1%. The Netherlands is sixth, with 207 researchers or 3.1% of the total, with no change from before.

Canada is seventh with 196 researchers or 3%, which is marginally up. Eighth is France with 146 researchers or 2.2% (down 0.4%) followed by Spain with 109 researchers or 1.7% (down 0.2%), and in 10th place is Switzerland with 102 researchers or 1.5% (down 0.7%).

While researcher performance is declining in the UK, it remains strong. The UK, Clarivate points out, “has a population one-fifth of the size of the US and one-twentieth the size of mainland China”.

Australia and the Netherlands, which have populations of only 25 million and 17 million respectively, also performed well relative to population size – as did Hong Kong, which shot from 60 to 79 highly cited researchers in a year, largely thanks to the University of Hong Kong more than doubling its number from 14 to 33 in the past year.

A sharp decline (0.7%) for Switzerland in one year reflected a change in methodology, Clarivate said. Papers with more than 30 institutional addresses were cut from its analyses in past years, and this year it eliminated papers with more than 30 authors or group authorship. The change, “judged an improvement in reasonably crediting individual authors”, impacted upon Switzerland heavily, especially researchers at the Swiss Institute of Bioinformatics.

For the first time, researchers from Bangladesh, Kuwait, Mauritius, Morocco and the Republic of Georgia are on the list, Clarivate said.

With a population of 1.38 billion people, India had only 22 highly cited scientists, while Pakistan (221 million people) had five and Indonesia (273.5 million people) had one – an associate professor in mechanical engineering at Medan State Polytechnic, which is located in the University of Sumatera Utara in Medan in North Sumatra.

Dr Arridina Susan Silitonga

According to the polytechnic, Dr Arridina Susan Silitonga was born in 1981, completed a bachelor degree in mechanical engineering at Andalas University, a leading Indonesian university, and earned a masters and a PhD at the University of Malaya.

Her research is in biofuels and in 2020, when she entered the Stanford University list of the top 2% of the most influential researchers in the world, she had published more than 50 influential articles in the ISI Web of Science within five years. This year’s citation lists 74 publications with a total of 5,084 times cited and 149 verified reviews.

Arridina has worked at Medan State Polytechnic since 2002. Last year its director, Dr Abdul Rahman, expressed pride and said he hoped her achievements would “motivate other lecturers to also produce scientific works and research on a national and international scale”.

“In the future we will try to increase the budget as a reward for researchers who produce works of national and international repute,” he added.

University World News asked Arridina how she managed to get so cited. She said that for 10 years she had been actively involved in research in renewable energy, particularly in biodiesel fields.

While a PhD student at the University of Malaya, she participated in establishing the biofuel laboratory in the energy field in the engineering faculty, with numerous colleagues. Support from High Impact Research grants from the university resulted in publication in Tier 1 ISI Web of Science journals.

“The fundamental research led to the generation of new knowledge in renewable energy. Developing countries such as Malaysia and Indonesia encounter similar challenges, especially in biofuel.” The research involved using edible and non-edible oil – which is widely available for biofuel production – and promoting the advantages of biofuels for transport and industry.

Arridina successfully completed several national and international research projects. “We actively collaborate with other researchers and universities in Malaysia, Australia, Taiwan, China and Saudi Arabia for joint research and publications. Research collaborations have created more learning outcomes, increased productivity, and enhanced knowledge transfers.”

Institutions with the high performers

There were 50 organisations – such as universities or government agencies, institutes or others – listed, though highly cited researchers on the Clarivate 2021 list are represented in more than 1,300 institutions around the world.

Harvard University, which is home to 214 researchers, “is once again the institution with the highest concentration of Highly Cited Researchers in the world,” said Clarivate.

The Chinese Academy of Sciences had 194 top researchers, and this year Clarivate counted the University of Science and Technology of China as part of the academy.

It was followed by Stanford University with 122 researchers; US National Institutes of Health with 93; the Max Planck Society in Germany with 70; Massachusetts Institute of Technology with 64; University of California, Berkeley with 62; Tsinghua University with 58; University of California, San Diego with 56 highly cited researchers; and the University of Oxford with 51.

Of the 50 highest ranked institutions on the list, 28 are in the US, four in mainland China, five in the UK, four in Australia, two in Singapore and Saudi Arabia, and one each in Hong Kong, Germany, Canada, the Netherlands and Belgium.

Exceptional performances

This is the fourth year that researchers with cross-field impact were identified. Of researchers named as highly cited in the 21 Essential Science Indicators (ESI)™ fields, 23 showed exceptionally broad performance, recognised for being highly cited in three or more fields.

“They are a truly global group – in North America, Europe, Asia and the Middle East,” said Clarivate. Professor Rob Knight from the University of California, San Diego was alone in being named in four ESI fields.

This year’s list includes 24 Nobel laureates, including five in 2021: David Julius from the University of California, San Francisco (physiology or medicine); Ardem Patapoutian from Scripps Research in the US (physiology or medicine); David WC MacMillan of Princeton University (chemistry); David Card of University of California, Berkeley (economics); and Guido Imbens of Stanford University (economics).

Joel Haspel, senior vice president strategy, science at Clarivate said: “As well as documenting the ‘Eureka!’ moments, our data tell the story of late nights spent filling in grant applications, poring over results in the lab, the unsung work of peer reviewing contemporaries’ manuscripts, and the many small failures that ultimately lead to bigger successes and accelerating innovation.”