Research institutions are converging on what they study

Where researchers go, their knowledge goes. And that shapes where innovation happens. “Recruiting researchers is one way institutions gain new knowledge and steer their research in particular directions,” explains Vito D. P. Servedio, senior scientist at CSH.

To learn more about whom institutions hire, how many new research topics those hires bring, and how institutions develop thematically over time, a team from CSH, in collaboration with Leiden University, reconstructed the career paths of 9.3 million researchers across 3,965 institutions worldwide. To do so, they analyzed 25 million scientific publications and traced the publication histories of their authors between 2000 and 2020. The study has been published in the journal Scientometrics.

Compared with one another, research institutions grew more similar in their research topics, the team found.

Servedio found this surprising. “I expected institutions to develop more distinct profiles,” he says. “Diversity in research can be valuable, because we often don't know what knowledge we'll need next.”

Within institutions, new hires generally fit well with the existing research profile. “The research topics of newcomers closely match those of the scientists already there,” Servedio says. On a scale from 0 (no overlap) to 1 (identical topics), the median topic alignment is 0.84. In other words, at half of the institutions studied, alignment is even higher than 0.84. At the other half, it is lower.

“We're not talking about broad fields like molecular biology or quantum physics,” study author and CSH president Stefan Thurner notes. “We're talking about very narrow, specific research topics.” The team used an established classification distinguishing between 4,163 of them.

The study also shows that the more prestigious an institution is, the more closely its new hires match its existing topics. This holds whether or not they had collaborated with colleagues there before.

Prestige was measured by an institution's share of publications among the 1% most cited in their topic. “By this definition, particularly prestigious institutions are more likely to hire researchers whose focus closely matches their own,” Thurner says.

For researchers who leave an institution, the median topic alignment is even slightly higher than for new hires, at 0.86. “This suggests that researchers move closer to their colleagues' topics during their time at an institution,” says Thurner.

Collaboration seems to play an important role in this. Among researchers who never published with colleagues at the institution, topic alignment drops to 0.54 for new hires and 0.61 for those leaving. “We can’t say whether collaboration leads to greater topic alignment or the other way around. But there is a connection. Since collaboration is something institutions can encourage, it may be a lever they can actively use,” says first author Márcia R. Ferreira.

At 41% of the institutions studied, both new hires and departing researchers fit the research profile particularly well, meaning their topic alignment is above the median of 0.84 for new hires and above 0.86 for those leaving. Examples include Ivy League universities and top European universities.

At 45% of institutions, alignment is below the median for both new hires and those leaving. Most of these institutions have citation performance at or below the global average – with one striking exception. “The Institute for Advanced Study in Princeton has very low alignment and high citation impact. It is built around visiting scholars rather than permanent hires. That shows more than one model can work – and high alignment is not a prerequisite for excellent research,” says Ferreira.

About 8% of institutions tend to bring in researchers with complementary topics, while those who leave fit well with their former colleagues.

At 6%, the pattern is reversed. These institutions tend to bring in researchers whose topics closely match their own, while those who leave tend to work on different topics than their former colleagues.

Alignment is somewhat higher in the biomedical and health sciences, the life and earth sciences, and the physical sciences and engineering. It is lower in mathematics and computer science and in the social sciences and humanities, especially at institutions with lower citation impact. “In these fields, people more often work alone or in small teams, without shared labs or equipment,” says Ferreira. “One explanation could be that with less day-to-day collaboration, there are fewer opportunities for topics to converge.”

Topical closeness within an institution has advantages. Earlier studies show that researchers who share a knowledge base can learn from one another more effectively and be more productive. But too much similarity may also slow innovation, the team notes. Every new hire is therefore also a decision: build on existing strengths or bring in new topics.

“Our method lets us measure, at scale, which path an institution actually takes,” Thurner says. “University leaders, funders, and policymakers could use it to check whether their hiring strategies match their goals, and to change course if needed.”

The study “Scientific mobility, prestige and topic alignment in research institutions” by M. R. Ferreira, R. Costas, V. D. P. Servedio, and S. Thurner has been published in Scientometrics.

The Complexity Science Hub (CSH) is Europe's research center for the study of complex systems. Drawing on large-scale data across economics, medicine, ecology, and the social sciences, CSH develops quantitative methods to understand the interconnected networks that underlie society – from financial markets and supply chains to public health and urban development. The goal is to provide a rigorous basis for navigating the challenges of an increasingly complex world.

Members of the Complexity Science Hub are: AIT Austrian Institute of Technology, BOKU University, Central European University (CEU), IT:U Interdisciplinary Transformation University Austria, Medical University Vienna, TU Wien, TU Graz, University for Continuing Education Krems, Vetmeduni, WU Vienna and WKO.