Who Leads Global Science and Who Follows: A global study on the circulation of scientific knowledge

A groundbreaking study led by Kimitaka Asatani from the Department of Engineering at the University of Tokyo explored the circulation of scientific knowledge worldwide to identify patterns of leadership and followership in scientific research. The analysis covered 71 million scientific articles indexed in Scopus (1970–2020) and mapped international co-authorship networks to understand how new research topics spread across nations.

Measuring scientific leadership: The Thematic Progression Index (TPI)

The TPI (Thematic Progression Index) is the key metric to assess thematic progress in science. It measures the extent to which a country leads or follows in adopting new research topics. The index combines the frequency of unique references in articles with temporal comparisons between nations, detecting leadership patterns or delays.

Key findings include thatWestern Europe, developed Anglophone countries, and Asian city-states such as Singapore and Hong Kong have maintained high TPI values for decades. Taiwan, South Korea, and Japan scored lower TPI values, despite working on similar topics to the U.S. and the U.K.
Switzerland achieved a high TPI with distinct topics, proving that thematic convergence is not required for progress.

Leaders vs. followers: The global science gap

In 2015, the U.S., the U.K., Canada, and Germany showed high thematic similarity, while China, India, and South Korea displayed weaker links. China developed research topics that the U.S. had already explored, revealing a time lag. Japan was also behind. Leadership remained concentrated in Western nations and select Asian city-states, leaving countries such as Brazil, Japan, or South Africa outside the core.

Leadership across research domains

The study examined 20 research clusters, finding that:

• Neuroscience, lifestyle diseases, infectious diseases, geology, and astronomy are dominated by Western countries.

• Social sciences/humanities, biology, physiology, and genetics show shared leadership between the West, Hong Kong, and Singapore—yet a persistent gap remains.

• Computer science, applied physics, cancer, civil engineering, dentistry, chemistry, agriculture, and energy feature Asian nations in the core, but without substantial thematic progress.

  
  

Case study – China: While central in computer science with a massive publication volume, its low TPI indicates that producing large amounts of research in a field dominated by another country does not necessarily drive progress.

The power of international co-authorship networks

International co-authorship networks are a major driver of scientific knowledge circulation. The study analyzed 16 million authors and 395 million collaborative links, applying metrics such as PageRank and eigenvector centrality—which measures how well connected a researcher is to the most influential nodes in the global network.

Researchers with high centrality gain early access to cutting-edge findings, influence the research agenda, and are more likely to set trends that others follow.
Countries like the U.S., the U.K., and Switzerland have a high proportion of strategically connected scientists, while China and Japan have fewer links to the Western core.

A persistent global science gap

Even with the growth of open access publishing and expanding scientific capacity worldwide, cutting-edge topics still emerge first in Western countries and specific Asian city-states.
Nations with high talent mobility and strong international networks achieve greater research impact.
Hong Kong and Singapore advanced rapidly through targeted strategies, whereas China and Japan—despite heavy investment—remain behind.

Closing the gap: Policy recommendations

The authors suggest that countries aiming to improve their thematic progress (TPI) should:

• Encourage international co-authorship.

• Promote researcher mobility.

• Attract and retain talent with strategic global connections.

By actively engaging in international scientific collaboration, emerging nations can integrate faster into high-impact research networks and shape the global science agenda.

Science and policy takeaway
Leading in new research topics doesn’t always equal more creativity—but it positions nations at the heart of global science. In today’s interconnected world, scientific connections matter as much as ideas.

Source: https://www.nature.com/articles/s41598-023-31452-8#MOESM1