Photo/Illutration The Asahi Shimbun

Japan fell outside the top 10 ranking of nations with the most highly cited scientific papers after being overtaken by Spain and South Korea, according to an education ministry report released on Aug. 9.

Japan ranked 12th in the average number of such papers published between 2018 and 2020, dropping two places from the previous report, which covered the years between 2017 and 2019.

The rankings were released in the report titled “Japanese Science and Technology Indicators 2022.” 

“The number of papers produced in Japan has remained almost unchanged in recent years, but its ranking has been falling as other countries are publishing more,” a ministry official said. 

The National Institute of Science and Technology Policy, affiliated with the ministry, calculated the rankings based on the top 10 percent of the most-cited scientific papers in each research field, and other factors.

While Japan accounted for an average of 3,780 of such papers between 2018 and 2020, the figure is less than 10 percent of that for China, which ranked top in the category with an average of 46,352 papers. 

Japan’s ranking has been declining since the mid-2000s, when the country stood in fourth place. The drop is particularly sharp in the fields of basic life sciences, chemistry and physics, in which Japan used to perform well.

China has been improving its performance by boosting spending on research and development.

The latest report showed the country overtook the United States to become first in the top 1 percent of the most-cited papers for the first time, while again coming out on top in the overall number of papers published and of the top 10 percent of the most-cited papers list.

China also ranked first in the number of corresponding authors of highly cited papers, which indicates the extent of each country’s contribution in leading global research. The United States came in second, while Japan was 12th.

Japan had 690,000 scientists and spent a combined 17.6 trillion yen ($130 billion) on research and development in the public and private sectors in 2020, ranking third only after the United States and China.

But those figures have not been rising much compared to other countries. Japanese universities’ research and development spending has remained almost flat since the 2000s, while the number of Ph.D. holders in Japan has been falling since fiscal 2006.