Based on the overall size of the U.S. contribution to S&E research publication output and the relative impact, as measured by citations to its S&E publications, the United States remains a highly influential nation. The publication output of the United States, Japan, the UK, and the countries of the EU-27 is concentrated in health sciences, while China and India focus more on engineering and computer and information sciences, respectively. In terms of S&E publication quantity, China’s output has grown rapidly and has now surpassed that of the United States. In terms of impact among S&E publications, China has increased rapidly in the last decade. The high-income economies (including the United States, the EU-27, and Japan) have slowly increased their large base of S&E publications, while middle-income and upper-middle-income economies have increased rapidly across production, collaboration, and impact beginning from a smaller S&E publications base.
International research collaboration is increasing, reflecting traditional cross-country ties and new relationships that stem from growing capabilities in the middle-income economies. Greater publication output—with greater and more diverse collaborations—means more countries are contributing, and many are doing so with U.S. authors.