Japan's ageing population threatens its scientific and technological pre-eminence, says the leading science journal Nature in a blistering editorial (July 9). In May last year, a government white paper warned that increasing international competition, especially from China, and older work force at home, Japan might "be forced out of the ranks of major international players and will risk losing [its] current plentiful and stable lifestyle". The outlook for Japanese science is grim.

"Between 1998 and 2007, the number of researchers in universities rose by 15%, from 146,000 to 168,000. But in the same period, the number of researchers younger than 37 years old shrank from 36,773 to 35,788, and now only account for 21% of the total. The future is bleaker. The number of university students who want to study science and engineering plummeted from roughly 1 million in 1992 to around 630,000 in 2008. How much longer can Japan afford to lose the talent that its system is either chewing up or simply not developing properly?"

One way of compensating for its ageing workforce is to attract foreigners. But formidable linguistic and cultural barriers make it difficult to draw scientists from overseas. Only 10% of PhDs from Japanese universities go to foreigners (compared with 42% in the US and 41% in the UK). Only 1.34% of scientists at Japan's universities and research institutes are foreigners. Contact with other countries is essential to prevent stagnation, but young Japanese scientists are homebodies. According to another white paper released last month, only 2% of Japanese researchers plan to work overseas. "As international competition for scientific talent intensifies, Japan is closing in on itself," warns Nature.

The government is aware of the problem and has some innovative policies. Kyoto University is trying to have one-third of positions for young scientists filled by women and half by foreigners. In Yokohama it is building a a ¥9.5-billion (US$100-million) science high school. Nearly 30 institutions have tenure-track systems offering independence to younger scientists. But with fewer and fewer young people, there are bound to be fewer young scientists.

"With little hope for a massive influx of creative thinkers from outside, Japan needs to fix the system that frowns on giving professorships and other opportunities to young independent scientists. How much longer can Japan afford to lose the talent that its system is either chewing up or simply not developing properly? In its chronic failure to provide sufficient incentives and support for young researchers' independence, Japan as a scientific power is marching right past its tipping point."