The study analyzed 14 million scholarly papers published between 2008 and 2015 by nearly 16 million individual authors. They found about 4%—more than 595,000 scholars—to be “mobile,” meaning they had affiliations with academic institutions in more than one nation between 2008 and 2015. Of these, roughly 73% are what the authors label “travelers”—those who retain a footing at their original institution while gaining additional international affiliations. The remaining 27%, who the authors call “migrants,” become detached from the institution in their original country after moving.
Migrants are the most highly cited, the study finds, even after the authors accounted for productivity, which is the number of papers a given researcher publishes. And, overall, mobile scholars are cited more than their colleagues who don’t move, but the extent depends on where you are in the world. Eastern European researchers see a hike of nearly 173% in citations when they are mobile, the study notes, whereas North Americans only experience a boost of about 11%.
The results don’t necessarily mean that researchers are always cited more because they moved, the study’s lead author, information scientist Cassidy Sugimoto of Indiana University in Bloomington, tells ScienceInsider. Instead, she says, opportunities for mobility may arise because of their previous citation record or potential to garner citations.
The study is “well done,” says Henk Moed, who formerly studied research assessment methodologies at Leiden University in the Netherlands and has reported extensively on scientific migration. But Sugimoto concedes that one of the study’s limitations is that it only looks at mobility from one country to another, excluding moves within a country. The 7-year study time period is also short to capture much mobility, she notes.
The study could have implications for policymakers who set immigration policies. For instance, although anti-immigration policies, such as the controversial U.S. travel ban on predominantly Muslim countries, typically target those wishing to permanently move to a new country, they are also having a “huge impact” on scholars who need short-term visas, Sugimoto notes. Trimming those short-term visits could have an impact on scientific collaboration, she notes, so “accounting for short-term stays when you’re making policy is really important.”
The take-home messages from the study, Sugimoto says, is that “science is a global activity,” and that “when scientists move, they perform better.”