Executive Summary
Key takeaways:
- The United States remains a highly influential nation in science and engineering (S&E) research, as measured by the volume of peer-reviewed scholarly publications and the rate of citations to those publications.
- In 2022, China remained the largest producer of publications, followed by the United States, then by India. China’s top scientific field in terms of number of articles produced was engineering (25% of all publications), whereas the top field in the United States was health sciences (37%), and India’s top field was computer and information sciences (21%).
- Analysis of funding acknowledgments shows that from 2018 to 2022, the scientific fields most frequently acknowledging federal funding are chemistry, biological and biomedical sciences, astronomy and astrophysics, and physics.
- The United States, the European Union (EU-27), and China currently produce a high number of highly cited articles, relative to their overall production.
- Open access (OA) has become an increasingly important feature of the publication landscape, in terms of output and impact, as shown by the growth of fully OA articles.
- International collaborations with U.S. authors of S&E publications have increased over the last 15 years, and China is the most frequent U.S. partner.
- International collaboration in the fast-growing field of artificial intelligence helps show an important research network and the most important collaborations in terms of absolute and relative size.
The primary method of disseminating research findings is through publication of peer-reviewed journal articles and conference proceedings (i.e., publication output). Data on publication output indicate a continued increase in global research activity, a growth in the proliferation and impact of some categories of OA research, and an internationally connected research ecosystem.
Global publication output reached 3.3 million articles in 2022, based on data from the Scopus database of S&E publications. The regions, countries, or economies with the largest volume of S&E publications in 2022 were China, with 27% of global output, and the United States, with 14%. From 2012 to 2022, the global yearly publication total grew by 59%. In terms of growth for these two largest producers, China and the United States had noticeably different expansion in their levels of overall production (growing by 173% and 6%, respectively).
Beyond differences at the level of region, country, or economy, the number of OA publications has increased dramatically in the last 10 years. In 2022, nearly 1.6 million articles were OA (classified in one of four OA categories), compared with about 1.5 million traditional closed-access journal articles. Just 10 years prior, OA articles accounted for around a third of all articles with a known access status. This growth is also clear with respect to impact, where OA research as a whole has a higher proportion of highly cited articles relative to the size of OA scholarship.
When an article is cited by a high number of subsequent articles by other authors, it is deemed to have exceptional scientific impact. Analyzing the distribution of highly cited articles based on the authors’ locations, the United States has a long-standing record of producing a disproportionate share of such articles, although its share has decreased in recent years. China’s share of those articles grew consistently over the past 20 years, and its scientific impact is on par with that of the EU-27. That impact varies by scientific discipline. In 2020, publications by authors in the United States in materials science, geosciences, and physics had relatively higher scientific impact than those in other fields. For publications by authors in China for the same year, those in the social sciences tended to have higher scientific impact than those in any other field.
International collaborations continue to grow in their share of global scientific publications. From 2012 to 2022, the share of articles from authors affiliated with institutions in multiple regions, countries, or economies increased by 19%. In 2022, the United States was involved in a high number of international collaborations (40% of U.S. articles produced included an international coauthor). Other top producers like China (19%), India (24%), and the United Kingdom (67%) varied in the concentration of international collaborations among their respective total outputs.