8.4Tracking the evolution of Flemish co-authorship with neighbouring countries, and with the scientific powerhouses including China and the U.S.

By Eline Vandewalle and Tim Engels (ECOOM, University of Antwerp)

International scientific collaboration has been increasing over the last decades. This also influences the co-authorship patterns of Flemish researchers, who collaborate more with international colleagues than ever before. Not only bilateral collaboration³ (with one other country), but also multilateral collaboration (with two or more other countries) has increased over the past two decades. In this dossier, we relate the trends of Flemish international collaboration with its immediate neighbours (the Netherlands, the UK Germany, France and Luxembourg) as well as with the global scientific powerhouses China and the US in the period 2000 to 2024. Additionally, we trace the evolution of the relative importance of bilateral and multilateral collaborations with these countries through the Relative Intensity of Collaborations (RIC). In doing so we provide perspective beyond the absolute numbers of collaborative papers. As the share of global scientific output that countries produce evolves over time (see also chapter 2) both the evolution of collaboration in terms of absolute numbers and in terms of relative intensity provide valuable insight into how Flemish research collaboration is evolving.  

Several studies have reported a general increase in co-authorship and in international co-authorship in particular (Aksnes & Sivertsen, 2023; Olechnicka et al., 2019; Thelwall & Maflahi, 2022). This is related to developments such as big science and team science. There is also a significant policy push towards incentivising international partnerships, e.g. deepening scientific integration through EU framework programmes. International collaboration is further associated with higher citation impact (Wang et al., 2024).

China and the US are the two largest economies worldwide as well as the two largest producers of research output in the world. As such, they are both key partners of international scientific collaboration. However, while the US was the dominant scientific power for much of the 20^th century, China has rapidly increased its presence in terms of scientific outputs. There has been some media attention to the growth of the Chinese research system, which overtook the US in terms of output in the Web of Science (Lu, 2022). More recently, there have also been security concerns voiced by many Western countries regarding scientific collaboration and exchange with China. A recent study shows that scientific exchanges between the US and China are declining since 2018-2019 (Tang, 2024). A study on Belgian-China research collaboration problematises the links of some of these collaborations to Chinese military power, and notes increases in research collaboration between Belgium and China (Houttekier et al 2025). However, the study relies mostly on absolute numbers to show this evolution. When assessing the growth in research collaboration with China, it is important to consider the dizzying growth of the Chinese scientific system in 21^st century, which significantly influences its collaboration patterns with individual countries. In this dossier, we present both the absolute size of research collaboration as well as an indicator for the relative intensity of collaboration (RIC).

The data presented here focuses on Flanders and showcases to what extent Flemish researchers collaborate with neighbouring countries, with the US, and with China and how this relationship has evolved over time. While from the point of view of the US and China, Flanders may be viewed as a minor scientific partner, collaborations involving China and the US represent an important part of Flanders’ scientific output. The UK also offers an interesting case as it has very strong ties to the European research system but has experienced significant uncertainty over its future in the European research system after the Brexit referendum.

The largest pool of collaborators for Flanders can be found in neighbouring countries, including in the UK. Connections between Flanders and its neighbouring countries remain strong, both in terms of bilateral and multilateral collaborations.

Throughout this dossier, we use international co-authorship as a measure of international collaboration. It must be noted, however, that while co-authorship is a widely used measure for collaboration, there are types of collaboration that are not captured by co-authorship data, such as co-inventorship of patents. Further limitations of this approach include the fact that we do not account for multiple affiliations (one author may be affiliated with organisations in multiple countries), which is not strictly speaking evidence of scientific co-authorship.