Migrant Inventors Boost Innovation in Both Home and Host Countries
Economist Marta Prato argues that inventor migration is not simply a brain drain from origin countries to richer destinations. In her analysis for the Hoover Institution, high-skilled inventors often become more productive after moving abroad, while former collaborators at home can also benefit when professional ties continue. The implication, she says, is that migration policy should account not only for the movement of workers, but for the cross-border movement of knowledge.
Inventor migration moves knowledge, not just people
Marta Prato, an assistant professor of economics at Bocconi University and visiting fellow at Stanford SIEPR, studies immigration through its effects on innovation and economic growth. Her focus is how high-skilled inventors’ moves change the flow of knowledge across borders: who they continue to work with, how their own productivity changes, and what happens to collaborators who remain in the home country.
The central finding is that migrant inventors tend to become more productive after moving across countries. Prato says the more striking result is that their former coworkers in the home country also tend to become more productive after a co-inventor moves abroad.
That finding complicates the standard “brain drain” frame. The sending country loses the direct contribution of a skilled person who leaves. But Prato’s research adds a second channel: migrants often remain connected to collaborators at home, especially when both sides are part of the same multinational company. Through those continued collaborations, the migrant shares knowledge and expertise gained in the destination country’s innovation ecosystem with former coworkers in the origin country.
The most striking fact is that actually, even their collaborators, so their former coworkers who are left behind in the home country, also tend to experience an increase in their productivity when one of their co-inventors moves abroad.
In Prato’s account, the destination country benefits from the migrant inventor’s direct work and from the expertise brought into new teams. The origin country is not simply cut off from the inventor’s knowledge if collaboration continues. Some of that knowledge can travel back through professional ties, joint work, and multinational-company relationships.
Brain drain is only part of the sending-country calculation
For sending countries, Marta Prato argues, inventor migration is not only a story of loss. Developing economies and many European countries send inventors to the United States. They lose the direct innovation output those inventors would have produced at home. But Prato says her research documents a countervailing effect: knowledge transferred back by migrants can offset part of the negative effect of brain drain.
Her example is European countries. In her findings, they would be worse off trying to completely shut down the out-migration of inventors, even if such a policy were possible, than they are under the current situation. The current arrangement still involves brain drain. But it also preserves the knowledge links created by migrants abroad.
Prato is not saying emigration has no cost for origin countries. She explicitly describes the loss of direct contributions to domestic innovation. Her claim is narrower and more policy-relevant: preventing inventor out-migration would also eliminate the knowledge-transfer mechanism that can arise when migrants keep collaborating with people at home.
That distinction changes how the gains from migration are assigned. If an inventor leaves a sending country for the United States, the receiving country gains access to that person’s talent. But the origin country may continue to benefit if the inventor remains tied to collaborators there and shares expertise acquired in the destination country’s innovation system.
H-1B expansion is not just a headcount question
Marta Prato applies the same logic to US high-skilled immigration policy, specifically the H-1B visa program. In her analysis, the effects of expanding H-1B visas are not only about how many immigrants come to the United States. They also depend on migrants’ skill levels, expertise, and how they interact with American workers.
Immigrant inventors, Prato says, tend to be highly skilled, knowledgeable, and expert individuals. Their expertise can benefit their new American coworkers. They do not merely add workers to the labor market. They enter teams, share knowledge, and contribute to the innovative capacity of the economy.
That is why Prato describes H-1B expansion as potentially beneficial. Immigrant inventors enlarge the US innovative talent pool, strengthen the economy’s capacity to innovate, and contribute ultimately to economic growth.
About one out of four inventors in the United States are currently immigrants. Prato links that presence to the expansion of US innovative capacity and to the country’s position as one of the technological leaders in the global economy.
Her warning about restriction is tied to innovation rather than only to labor supply. Policies that reduce high-skilled immigration, she says, risk slowing US innovation in ways that are hard to reverse. The potential loss is not only fewer immigrant inventors; it is less knowledge and expertise entering the teams and workplaces where innovation is produced.
The zero-sum framing misses how inventor knowledge spreads
Marta Prato’s broader claim is that migration policy should not be treated as a zero-sum contest between sending and receiving countries, or between immigrants and native workers. For inventor migration, the relevant question is not only who crosses a border or who fills a job. It is how knowledge moves through collaboration.
When immigrant inventors come to the United States, they bring knowledge and expertise, produce new knowledge, and benefit American coworkers. To some extent, they also continue benefiting their home countries through knowledge transfer.
Migration policy is not just about the movement of people across borders, but ultimately it's fundamentally about the movement of knowledge as well.
The argument is not that every migration flow benefits everyone equally. It is that for high-skilled inventors, the effects run through collaboration, expertise, and knowledge sharing. A policy debate that counts only people crossing borders, or only workers gained and lost, misses the mechanism Prato identifies as central to innovation: knowledge can keep moving after the inventor moves.