“Countries and universities with a broader international network seem to be more resilient”

For the current issue of “Wissenschaft weltoffen”, you looked at exogenous shocks and their effects on international researcher mobility. How exactly did you go about this and what data is available for such analyses?

I based the analysis on publication data from the Scopus database. Scopus records publications of scientific authors and the country of the institution they were affiliated with at the time of each paper. This means you can track a researcher’s “location history” based on these data. For every researcher, I identified the country that appeared most often in each year. When that most common country changed from one year to the next, I counted it as a move. It’s not perfect, of course. There are a few things to keep in mind. The method only detects moves for people who publish regularly, and moves could appear with a delay because the change only becomes visible once the next publication comes out. But it works for large-scale trends.

I then compared mobility patterns before and after two major shocks. For Brexit, I looked at the three years before the referendum and the three years after, so the pandemic wouldn’t distort the results. For the Covid-19 pandemic, I first established the long-term trend up to 2019. Then I examined what happened in 2020, 2021 and 2022 and compared that with the trend we would have expected without the pandemic. I also checked a few countries separately because the impact could be different in each country depending on national policies and border restrictions.

Let’s move on to the findings of your analysis: How would you summarize the most important results? And which ones surprised you the most?

Brexit didn’t trigger a collapse in international researcher mobility, but it clearly changed the patterns of mobility. The biggest change was that the UK used to attract more researchers than it lost, but now it loses more than it gains. Outflows increased, especially to EU countries, while inflows from the EU stayed more or less the same. At the same time, flows between the UK and countries outside Europe, like China, India and the United States, became stronger.

For the Covid-19 pandemic the most important result is a slowdown of the global international researcher mobility. Mobility didn’t suddenly fall off in 2020, but the growth stopped. 2021 was the first year ever when global mobility decreased in comparison to previous years. In 2022, we can see some recovery, but the number of internationally mobile researchers would have been higher without the pandemic with a high degree of probability.

The biggest surprise was China. Even with strict border controls, the number of people moving into China kept rising. I expected that the pandemic’s effect would be different in different countries as it would depend on the countries’ policy measures that were introduced in response to the pandemic. But the China case doesn’t match this expectation. It’s definitely something worth looking into more in future research.

Against the backdrop of these findings, what practical conclusions or recommendations for action for universities and higher education policy do you think can be drawn from this?

The data shows that the impact of the pandemic was uneven. Some countries saw a big decrease in mobility and still haven’t reached their old levels. Others slowed down only briefly and recovered quickly. It would really help to understand why these differences exist. Is it the structure of the academic system, the way borders were managed, or the support policies that came right after the crisis? Studying these differences would give us a better idea of how to deal with the next major disruption.

The second point comes from looking at both Brexit and the pandemic together. External shocks can shift mobility flows quite quickly. We can see this clearly in the UK case, where inflows and outflows changed direction within a few years. In situations like this, countries or universities that rely heavily on a small number of international partners are more at risk. Those with a broader international network seem to be more resilient, because they’re not tied to one region or one political context. So, a practical takeaway is to keep international partnerships as diverse as possible. This makes systems better able to adapt when sudden changes happen.