A half-century of international research collaboration dynamism: Congregate or disperse?

The past decades have witnessed a dramatic change in researchers' collaboration mode across borders. In addition to purely academia-driven collaborations, various state-led initiatives have also been developed and are underway, reflecting the rapidly changing geopolitical situation of the contemporary world. In such multilayered cooperative and competitive relationships among countries, it is of great interest to leaders in academia and the policy arena to grasp the full scope of international research collaboration and their country's place within it, along with its change over time. However, evidence for such world-scale dynamism is scarce to date. This paper provides unique evidence of how international collaboration clusters have formed and evolved over the past half-century for a broad set of scientific publications. Our analyses are based on data retrieved from OpenAlex, a large-scale Open Bibliometrics platform launched in 2022. The science and technology areas of focus include Quantum Science, Artificial Intelligence, Biotechnology and others, totalling 15. We first review the top-tier countries' global presence change for each discipline, measured by publication volumes and international collaboration rates. Notably, the US and China are shown to have rapidly moved closer together for decades but have started moving apart after 2019. Subsequently, we analyse and visualise the international collaboration clusters for each discipline and period based on a hierarchical clustering method. Finally, we provide global-scale quantitative evidence for a 'Shrinking World' of the past half-century's research collaboration. These results provide valuable insights into the big picture of past, present and future international collaboration.