China retains crown in scientific papers, widens lead over U.S.
Japan declines in most-cited studies to 13th place, outstripped by Iran
TOKYO
-- China has maintained its global lead in three measures of the
quantity and quality of scientific research papers, a report from
Japan's education ministry shows, a testament to the country's
increasingly independent research system that does not rely on the West.
The annual report released Tuesday, based on data from British firm Clarivate, centered on 2020 figures, taking the three-year average through 2021. China produced 24.6% of all papers published worldwide -- a margin of 8.5 percentage points above the U.S. -- and nearly 30% of the top 10% and 1% most-cited publications.
The country widened its margin over the U.S. in all three categories.
China has ranked first in the share of published papers since 2017, the top 10% most-cited papers since 2018 and the top 1% since 2019.
Though China led for a second straight year, some observers argue that the country has risen up the ranks due partly to domestic researchers citing each other's work.
This year's report for the first time tallied the number of citations by institutions in the same country compared with overseas. It found that 29% of citations of U.S. papers were by American researchers, while the share of citations by domestic peers came below 20% for Japan, South Korea, the U.K., Germany and France. China was strikingly higher at 61%, up from 48% a decade earlier.
But this "does not change the fact that China's research capabilities are not to be underestimated," said the education ministry's institute that compiled the report.
China accounted for nearly 20% of papers in the prestigious journals Nature and Science -- far from the roughly 70% American share in both journals, but enough for fourth place behind the U.K. and Germany after surpassing Japan and France in the past decade. Other studies show that papers by top Chinese researchers are widely cited abroad.
Japan, meanwhile, fell from 12th place to 13th in the top 10% ranking. It was passed by Iran, which has a substantial presence in fields such as energy and thermodynamics and ranks fourth worldwide in the number of graduate students studying science and engineering at American institutions.
Iranian papers are cited frequently by researchers in China, India and Saudi Arabia, hinting at the emergence of a separate research community among developing countries in Asia and the Middle East.
Slow growth in doctoral degree holders has long been an issue for Japan. The country has shown signs of improvement in the past few years, including a rise in students entering master's programs after a long downturn, as well as an uptick in the share of students going on from master's to doctoral programs.