Overview of the State of the U.S. S&E Enterprise in a Global Context
Research produces new knowledge; refereed S&E publications are one of the tangible measures of research activity that have been broadly available for international comparison. The United States, the EU, and the developed world produce the majority of refereed S&E publications. However, similar to the trends for researchers and for R&D spending, S&E research output in recent years has grown more rapidly in China and other developing countries when compared with the output of the United States and other developed countries. China’s S&E publication output rose nearly fivefold since 2003, and as a result, China’s output, in terms of absolute quantity, is now comparable to that of the United States (Figure O-8). Research output has also grown rapidly in other developing countries—particularly, Brazil (not shown) and India.
S&E articles, by selected region, country, or economy: 2003–16
EU = European Union.
Article counts refer to publications from a selection of journals, books, and conference proceedings in S&E from Scopus. Articles are classified by their year of publication and are assigned to a region, country, or economy on the basis of the institutional address(es) listed in the article. Articles are credited on a fractional-count basis. The sum of the regions, countries, or economies may not add to the world total because of rounding. Some publications have incomplete address information for coauthored publications in the Scopus database. The unassigned category count is the sum of fractional counts for publications that cannot be assigned to a region, country, or economy. See Appendix Table 5-27.
National Science Foundation, National Center for Science and Engineering Statistics; SRI International; Science-Metrix; Elsevier, Scopus abstract and citation database (https://www.scopus.com/), accessed July 2017. For more information on the International Monetary Fund economic classification of countries, see https://www.imf.org/external/pubs/ft/weo/2016/01/weodata/groups.htm, accessed December 2016.
Science and Engineering Indicators 2018
The subject-matter emphasis of scientific research varies somewhat across countries and regions. Biomedical sciences (biological sciences, medical sciences, and other life sciences) and engineering—two fields that are vital to knowledge-intensive and technologically advanced economies—account for 57% of the worldwide total of S&E publications. In 2016, the United States and the EU produced significant numbers of global biomedical sciences articles, each larger than China’s production. However, China produced the largest number of engineering articles, surpassing the output of both the United States and the EU.
When researchers in one country cite the published work of researchers in another country, the resulting citation patterns are an indication of knowledge flows across regions. These patterns are strongly influenced by cultural, geographic, and language ties as well as perceived impact; for example, researchers are more likely to cite work written in their native language. U.S. articles disproportionately cite publications by Canadian and United Kingdom authors. In comparison, U.S. authors cite Chinese, Indian, and other Asian publications less than would be expected based on the overall publication output of these places.
Language factors notwithstanding, citations to refereed articles and presentations are an oft-used indicator of the use and impact of research output, and U.S. publications receive the largest number of citations. Adjusting for the size of each country’s research pool, researchers based in the United States, Canada, Switzerland, and several countries of northern Europe (Denmark, Finland, Iceland, the Netherlands, Norway, Sweden, and the United Kingdom) set the bar with respect to the production of influential research results. One measure of the influence of a region’s research is its share of the world’s top 1% of cited articles compared to what would be expected based on the size of each country’s pool of S&E publications. With this measure, if a country’s share is exactly what would be expected based on its publication output, the percentage is 1.0%. The U.S. percentage has held steady, at about twice the expected value (1.8%–1.9%), while the percentage of articles from the EU in the top 1% grew from 1.0% to 1.3% between 2000 and 2014 (Figure O-9). China’s share of this top 1%, starting from a low base, more than doubled in the same period, from 0.4% to 1.0%.
S&E publication output in the top 1% of cited publications, by selected region, country, or economy: 2000–14
EU = European Union.
An index of 1.00 indicates that articles are cited at their expected level. An index of 2.00 indicates that articles are cited at twice their expected level. The index measures the share of publications that are in the top 1% of the world's cited publications, relative to all the country's publications in that period and field. It is computed as follows: Sx = HCPx/Px, where Sx is the share of output from country x in the top 1% most-cited articles; HCPx is the number of articles from country x that are among the top 1% most-cited articles in the world; and Px is the total number of papers from country x in the database that were published in 2014 or earlier. Citations are presented for the year of publication, showing the counts of subsequent citations from peer-reviewed literature. At least 2 years of data after publication are needed for a meaningful measure. Publications that cannot be classified by country or field are excluded. Articles are classified by the publication year and assigned to a region, country, or economy on the basis of the institutional address(es) listed in the article. The world average stands at 1.00% for each period and field. See Appendix Table 5-26 and Appendix Table 5-51.
National Science Foundation, National Center for Science and Engineering Statistics; SRI International; Science-Metrix; Elsevier, Scopus abstract and citation database (https://www.scopus.com/), accessed July 2017.
Science and Engineering Indicators 2018
Collaboration on S&E publications between authors of different countries has risen over time, reflecting both an increased pool of trained researchers and improvements in communications technologies. Other drivers include budget pressures on R&D spending that increase the incentives for collaboration and sharing resources and also on the need to coordinate globally on challenges like climate change, infectious diseases, and the allocation of scarce natural resources (Wagner, Park, and Leydesdorff 2015).