|Table: Percentages of world share of publications using|
the 'Science Citation Index-Expanded version' at the ISI
Based on the 'Science Citation Index–Expanded' web-version, the United States (US) is still by far the strongest nation in terms of scientific performance. The relative declines of the US and the European Union (EU) in percentage share of publications are largely due to the emergence of China and other Asian nations (Taiwan, South Korea, and Singapore).
In 2006, China became the second largest nation in terms of the number of publications within this database. In terms of citations, the competitive advantage of the US "domestic market" is diminished, while the EU is profiting more from the enlargement of the database over time than the US.
However, the US is still outperforming all other countries in terms of highly-cited papers and citation/publication ratios, and it is more successful than the EU in coordinating its research efforts in strategic priority areas like nanotechnology. The People's Republic of China has now become second largest nation in both numbers of papers published and citations behind the US in this priority field (Kostoff, 1994).
Loet Leydesdorff & Caroline Wagner, Is the United States losing ground in science? A global perspective on the world science system (updated for 2006), Scientometrics (forthcoming).
Ron Kostoff, R., 'The (Scientific) Wealth of Nations', The Scientist, 18, 10 (2004)