Key takeaways
• High-skilled migration can lead to brain drain, but it also fosters international knowledge transfers that boost productivity in both origin and destination countries.
• The most effective migration policies will not only seek to attract or retain talent but also preserve the cross-border channels through which ideas and knowledge spread.
The debate over high-skilled immigration
Debates over the economic effects of high-skilled immigration have become central to discussions of immigration policy, with proposals ranging from easing visa caps to tightening eligibility. But how do such policies shape not just where talent moves, but also how knowledge flows and innovation spreads across borders?
These debates reflect a fundamental tension: High-skilled migration can both enrich and disrupt economies. For origin countries, the loss of talent raises fears of “brain drain”—yet emigrants can also serve as conduits for knowledge transfer back home. For destination countries, migrants boost innovation but may also displace domestic workers.
Migration between the US and EU: what the data show
A recent study focuses on a specific category of high-skilled workers: inventors—individuals who develop new technologies and file patents. Using detailed patent data to track them across borders, this research examines migration patterns, productivity, and collaboration networks along the United States-European Union corridor, which contains one of the most active flows of high-skilled talent.
A key finding is that US-EU migration flows are highly asymmetric. Immigrants account for about 22 percent of international patents filed in the United States, with roughly a third coming from EU immigrants. In contrast, only 3 percent of international patents in the EU are filed by immigrants. Another key finding is that inventors become more productive after moving: On average, migrants increase their annual patent production by a third after relocating.
Migration also reshapes collaboration networks. While local inventors mainly collaborate with fellow inventors based in the same country, migrants develop more diverse networks spanning their origin and destination countries. After moving, inventors form new ties in their new locations but maintain ties with colleagues back home, building bridges for international knowledge transfer.
The analysis also finds that local inventors become more productive when a close collaborator migrates, despite no longer being collocated in the same country. On average, inventors who remain in the origin country increase their patent output by 16 percent in the five years following a coinventor’s emigration. The gains are strongest when collaboration continues after the move, suggesting that emigrants serve as vectors for knowledge spillovers. Even when talent leaves, it can enhance innovation at home through sustained professional ties.
Linking talent mobility to innovation and growth
To understand what these facts imply, the study introduces a framework that allows us to evaluate the benefits and potential drawbacks of migration for origin and destination countries, shedding light on the different ways that high-skilled migration affects innovation and knowledge diffusion.
The framework indicates that cross-border knowledge transfers channeled by migrants help offset the negative effects of brain drain. Restricting migration entirely would be harmful to both sending and receiving countries: In a scenario where EU inventors can no longer move to America, long-run growth rates would fall in both regions.
How migration policies shape innovation across borders
The framework can be used to evaluate hypothetical policy measures. Consider first relaxing US immigration caps for high-skilled workers—for example, doubling the annual inflow of foreign inventors, similar in spirit to reforms proposed for the H-1B visa program. This would increase the total number of inventors in the US and expand its innovation capacity. The EU would initially see innovation fall due to talent outflows, but over time would benefit from enhanced knowledge spillovers from the US. In the long run, both regions would experience a slight increase in the annual growth rate.
Now consider a policy for the EU: lowering the tax rate for foreigners and return migrants, as several EU countries have done. Such a policy would lead to a reallocation of inventors toward the EU, a permanent increase in innovation, and a short-term boost in output. But the long-run effects are also shaped by negative forces: The policy may draw inventors away from more productive opportunities simply to benefit from tax incentives, and reduced migration flows may limit international learning opportunities. A modest tax cut that stops the EU-to-US brain drain would slightly lower the long-run growth rate because the losses from reduced learning and diffusion would outweigh the gains from talent retention. In contrast, a much larger tax cut that attracts US inventors to the EU could relocate the global innovation frontier to Europe, raising long-run growth and setting the EU to become the new technological leader in the global economy.
Implications for policy
There is an overarching message from these findings: Managing high-skilled migration is not simply about retaining or attracting talent within national borders. It also shapes the broader global innovation ecosystem. Policies that increase the international flow of inventors, such as loosening US visa caps, can generate shared gains in long-run growth through stronger innovation and cross-border knowledge spillovers. Conversely, policies aimed at reversing brain drain, like EU tax incentives for returnees, can boost domestic innovation in the short run but risk diminishing global learning if they reduce the connectivity of talent across borders. The most effective migration policies will enhance talent mobility while preserving the international channels through which knowledge spreads.
Note: This research brief is based on the working paper “The Global Race for Talent: Brain Drain, Knowledge Transfer, and Growth” by Marta Prato (November 17, 2024).
Marta Prato is an assistant professor of economics at Bocconi University in Milan, Italy.
