SCIENCE & ENGINEERING INDICATORS

A region’s, country’s, or economy’s distribution of publications by field of science can indicate their research priorities and capabilities. Health-related research, which includes health sciences plus biological and biomedical sciences, is the largest global field of science (36% of publications) (Table S5a-17). In the United States and EU, health-related research and engineering are the largest scientific fields. In China, the largest research area is engineering (25%) followed closely by health-related research (23%); computer and information sciences (13%) is a distant third (Figure 5a-4). Japan has a portfolio with health-related research (43%) at the top followed by engineering (15%) and physics (13%) (Figure 5a-4).

The specialization index allows for the comparison of research concentration or focus areas among regions, countries, and economies. The specialization index normalizes a country’s share of output in a field of science with the total global share of output in that field (Science-Metrix, 2018). For example, astronomy and astrophysics articles comprised 0.8% of the U.S. S&E publication output (Table S5a-17). Normalizing the 0.8% by the world average of 0.5% in that field shows the U.S. specialization index for astronomy and astrophysics is 1.6, which is above the world average of 1.0 (Table S5a-17 and Table S5a-19). The specialization index also permits comparison across countries, revealing that the U.S. concentration is on par with several other countries but below that of Chile (5.5) (Table S5a-19), which houses many of the world’s leading observatories.

Figure 5a-5 shows fields (blue) where the region, country, or economy has a concentration above the world average. The figure reveals that the United States has above-average concentrations in psychology (2.0), astronomy and astrophysics (1.6), social sciences (1.6), health sciences (1.4), biological and biomedical sciences (1.2), and geosciences (1.2). The EU has similar focus areas as well as mathematics and statistics (1.1) and natural resources and conservation (1.0). The concentration areas for China show more focus in chemistry (1.6), materials sciences (1.6), engineering (1.5), natural resources and conservation (1.3), computer and information sciences (1.2), physics (1.1), and agricultural sciences (1.1). Researchers find that G7 countries^{​The Group of Seven (G7) is an international intergovernmental economic organization consisting of the seven largest International Monetary Fund members: Canada, France, Germany, Italy, Japan, the United Kingdom, and the United States.} emphasize the life sciences while BRIC countries^{​A grouping acronym referring to the countries of Brazil, Russia, India, and China.} focus on physics, chemistry, mathematics, and engineering (Yang et al. 2012).

The U.S. specialization index scores have increased from 2008 to 2018 for astronomy and astrophysics, geosciences, health sciences, and psychology (Figure 5a-6). The 18% increase in the health sciences index from 2008 to 2018 demonstrates the increasing concentration of the United States in health sciences and aligns with federal spending patterns in life sciences (see Figure 4-11 "Federal obligations for research, by agency and major S&E field: FY2017" in the forthcoming Indicators 2020 report Research and Development: U.S. Trends and International Comparisons).