Source-linked AI summary
Is the United States losing ground in science? A global perspective on the world science system
Loet Leydesdorff, Caroline Wagner
TL;DR
The study examines whether the USA is losing ground amid competition from an expanding European Union and emerging Asian nations. It places recent data, including 2006, in the context of the previous decade and finds continued US leadership, especially among highly cited papers and in nanotechnology coordination.
Problem
The study addresses concern that the USA is losing ground to competition from an expanding European Union and emerging Asian nations.
Method
The study presents recent data, including 2006, in the context of developments over the previous decade.
Results
The USA remains much more successful than the EU in coordinating research efforts in strategic priority areas like nanotechnology, while China ranks second behind the USA in nanotechnology.
Takeaways & Limitations
The USA retains a leading position in highly cited papers and nanotechnology coordination despite competition from emerging countries.
Takeaways & Limitations
Citation measurement is difficult to standardize online, and machine-generated citation counts should be treated as statistical.
Abstract
from arXiv · showhide
Based on the Science Citation IndexExpanded webversion, the USA is still by far the strongest nation in terms of scientific performance. Its relative decline in percentage share of publications is largely due to the emergence of China and other Asian nations. In 2006, China has become the second largest nation in terms of the number of publications within this database. In terms of citations, the competitive advantage of the American domestic market is diminished, while the European Union EU is profiting more from the enlargement of the database over time than the US. However, the USA is still outperforming all other countries in terms of highly cited papers and citationpublication ratios, and it is more successful than the EU in coordinating its research efforts in strategic priority areas like nanotechnology. In this field, the Peoples Republic of China PRC has become second largest nation in both numbers of papers published and citations behind the USA.
1. Introduction
The study places recent science-performance data in a decade-long context and finds that the USA remains the leading scientific nation. China and other Asian countries are expanding output, while the EU-25 faces internal problems despite its larger size and population.
- Earlier studies raised concerns about US decline relative to Europe and China in publication shares and absolute output.
- The study compares recent data, including 2006, with developments over the preceding decade.
- The USA remains by far the leading nation in the world of science.
- The EU-25’s larger publication count and population do not eliminate endogenous problems in its science system.
- China and other smaller Asian nations continue expanding scientific output along exponential and linear trajectories, respectively, rather than displacing other performers.
2. Methods and data
The analysis uses Science Citation Index–Expanded data to compare national publication and citation performance, with a journal-based representation of nanoscience and nanotechnology. Publication counts cover citable articles, reviews, and letters, while country attribution gives each participating country a full point.
- Data come from the expanded Science Citation Index available through the Web of Science.
- Publication counts include research articles, reviews, and letters, with country identification based on the field tag “cu=”.
- World-share calculations assign one full point to every country on internationally co-authored papers, so shares can exceed 100%.
- The EU-25 series corrects for within-Europe co-authorship.
- Nanoscience and nanotechnology are represented by ten journals selected from 38 chemistry and applied-physics journals using betweenness centrality and citation data.
- The specialty is not yet stabilized in a core journal set because relevant papers appear across many specialties.
3. Results
Publication growth increasingly reflects China and other Asian countries, while the EU benefits more than the USA from database expansion. Citation measures show a narrower US advantage: the USA remains strongest in highly cited papers, although its citation-share lead has diminished.
- Smaller countries show divergent trends: Switzerland and the Netherlands stabilize their shares, while South Korea rises steadily with r^2 > 0.99.
- China’s publication output follows sustained exponential growth, associated in the discussion with expanding research capacity and incentives to publish.
- The database expanded by more than 25,000 citable items per year on average; the USA contributed approximately 20% of this increase, compared with 41% for the EU.
- The EU-25 improved its share of database growth more than the USA in almost all years, whereas China’s erratic pattern indicates other performance mechanisms.
- Citation measurement is difficult to standardize because citations accumulate over time and depend on the data-collection date.
- The USA outperformed the EU on the highly cited-paper quality indicator, while citation-share curves for the EU-15 and USA grew closer together over the decade.
- The USA lost ground in citation numbers as its average paper became increasingly similar to the average European paper in citation impact, while East Asia-4 citation shares followed an exponential curve with r^2 > 0.99.
4. Nanoscience and nanotechnology
The paper examines nanoscience through publication and citation patterns, using a core set of ten journals and a 2002–2006 comparison of leading countries and the EU-25. The USA remains strong, while China gains ground and the EU declines in publication and citation performance relative to East Asia.
- Scope and method: The study represents nanoscience and nanotechnology using ten core journals and analyzes their publications and citations.The journal set is treated as a specialty representation, with document types and the period limited for comparative analysis.
- Publication patterns: In 2006, China held 15.3% of the publication share in the selected nano-journal set, ahead of Japan at 10.8%.The paper states that China’s growth is not exponential and that U.S. growth is at least as strong in absolute numbers.
- Publication patterns: The paper identifies declining EU contributions as consistent with a European paradox in using research potential strategically compared with the USA.
- Citation patterns: In citation performance, the EU-25 falls behind the USA and loses ground more rapidly than the USA to the East Asia-4.The citation analysis covers articles, reviews, and letters published from 2002–2005 and measured citations online on October 1, 2006.
- Limitations: The citation results are statistical because counts are machine-generated, although autocorrelation across consecutive years is expected to reduce their effect on the general trend.
5. Conclusions
The United States and other advanced countries maintain or increase their scientific output while newly developing systems make rapid publication gains, reducing established countries’ percentage shares without an absolute loss. China’s rise is especially pronounced, while the USA retains a substantial advantage in highly cited research and strategic coordination.
- Global growth: Newly developing scientific systems are making spectacular publication gains, while the USA and other advanced countries maintain slower growth.The resulting expansion reflects broader growth of the global scientific system rather than a simple displacement of established countries.
- Global growth: The USA and EU are losing percentage share of all publications, but this decline is not an absolute loss of ground.New countries’ contributions expand the publication pool as the scientific system grows.
- Citation patterns: Papers from the USA and EU are becoming more equal in citation terms.This indicates convergence in citation performance even though the USA remains stronger in highly cited papers.
- Competitive position: The USA remains far ahead in the top 1% of highly cited papers and is more successful than the EU in coordinating research in strategic areas such as nanotechnology.The comparison concerns the top segment of highly cited papers and coordination of research efforts.
- Asian expansion: China shows exponential growth across absolute and relative indicators, while South Korea, Singapore, and Taiwan show sustained mostly linear growth.China’s expansion is also reflected in nanotechnology, where it ranks second behind the USA in publications and citation world share.
- Global integration: As countries develop scientific capacity, the USA and other advanced countries gain new colleagues, partners, and access to resources rather than simply losing ground.The paper frames global science as codified and networked, with new knowledge adding to the system as a whole.