International Migration

One of the most contentious debates in the migration and development literature concerns whether the departure of highly skilled workers from developing countries represents a net loss (‘brain drain’) or can actually increase human capital formation in origin countries (‘brain gain’).[1]1. For extensive reviews, see Gibson and McKenzie (2011), Docquier and Rapoport (2012), and Batista et al. (2025).  The traditional brain drain concern focuses on the direct loss of human capital when educated workers emigrate. When doctors, engineers, scientists, and other skilled professionals leave developing countries, they take with them years of education and training, often subsidised by their home governments. This direct loss can be substantial: across sub-Saharan Africa, the Caribbean, and the Pacific, people with tertiary education are 30 times more likely to emigrate than those who are less educated (Docquier et al. 2007). In some countries, emigration rates for specific skilled professions reach extraordinary levels. For example, 91% of Ethiopian-born PhD holders and one-third of doctors trained in Ghana have emigrated (Batista et al. 2025a). Such human capital loss is often deemed particularly concerning in the case of medical professionals due to the potential negative externalities on health in the local population.

In theory, migration opportunities can incentivise human capital investments in origin countries, potentially leading to net ‘brain gain’ effects (Stark et al. 1997, Mountford 1997, Beine et al. 2001, Ortega 2005, Batista et al. 2012). Migrant remittances can pay for educational costs, and the prospect of future migration can also incentivise educational investments that would not have occurred otherwise. If not all of those who invest in education actually migrate, the origin country can end up with more skilled workers than it would have had without the migration opportunity.[2]2. Early empirical evidence for these brain gain effects came from cross-sectional and panel data studies. Beine et al. (2008) provide evidence using emigration data by education level, showing that countries combining relatively low levels of human capital and low emigration rates experience brain gain.

Empirical evidence using credible identification strategies has found such effects: migration opportunities can actually increase rather than decrease the total stock of skilled workers in origin countries. Recent studies carefully establish causality by exploiting sudden policy changes that generated exogenous variation in migration opportunities. Abarcar and Theoharides (2024) provide compelling evidence of brain gain in the context of Filipino nurse migration. When the US expanded work visas for foreign nurses between 2000 and 2006, enrolment in Philippine nursing programmes increased dramatically. For each nurse who migrated to the US, approximately nine new nurses were licensed in the Philippines, resulting in a substantial net increase in the country’s nursing workforce. This effect was facilitated by the expansion of nursing programmes, particularly at already established private institutions, demonstrating the importance of having flexible educational infrastructure that can respond to increased demand. Enrolment increases were largely driven by new nurses switching from other degree types. However, those enrolled in nursing programmes persisted to degree at a higher rate, leading to an overall increase in the stock of tertiary-educated labour in the Philippines.

Shrestha (2016) demonstrates brain gain in a different context, examining how the British Army’s shift towards education-based recruitment criteria for Nepalese Gurkha soldiers increased human capital investments. Recruitment to the British Gurkha Brigade is a low probability, high return migration opportunity. When education became a requirement for military service abroad, eligible Gurkha males increased their completed years of schooling by over one year on average. Crucially, the net effect was positive even after accounting for those who emigrated, as the vast majority of those who invested in education remained in Nepal.

Similarly, Khanna and Morales (2023) provide compelling evidence of brain gain in the context of Indian IT workers and US immigration policy. Leveraging variation in H-1B visa caps and demand shocks, they demonstrate that increased migration opportunities to the US induced substantial educational and occupational responses in India. When the propensity to migrate increased, there was a meaningful shift towards computer science majors and occupations among populations with stronger migrant connections to the US. While the H-1B programme facilitated some migration to the US, visa caps meant that many skilled workers who had acquired computer science skills remained in India, creating a substantial brain gain. Return migration (‘brain circulation’) complemented these forces, and contributed to the expanding IT workforce in India. This educated workforce enabled rapid growth in India’s IT sector, with the country eventually becoming a major exporter of software and overtaking the US in IT exports by the mid-2000s.

Chand and Clemens (2023) also find brain gain effects in the context of Fiji. They focus on a natural experiment that led to an increase in discrimination towards ethnic Indians in Fiji. Skilled migration was the primary exit strategy for this ethnic group. As such, increased discrimination induced increases in both education and emigration. However, not all ethnic Indians migrate, and the human capital of those remaining in Fiji increases, with 1.1 new skilled workers in Fiji for each skilled worker who migrated.

Historical evidence provides additional support for long-term brain gain effects. Fernández Sánchez (forthcoming) examines the century-long impacts of mass emigration from Galicia (Spain) to Latin America, finding that while emigration initially reduced literacy rates, it generated substantial and persistent human capital gains in future decades. The study identifies two important mechanisms: diaspora-funded school construction, where Galician migrant associations financed educational infrastructure in their origin communities, and norm diffusion, where migrants transmitted beliefs about the value of education that created lasting cultural changes. These effects demonstrate how temporary migration episodes can generate lasting improvements in human capital through diaspora investment and cultural transmission channels.

Some directions for future research are likely to be fruitful. It is important to investigate conditions under which outmigration of skilled individuals leads to brain gain or brain drain. First, it may be necessary that the origin country have flexible and responsive educational institutions that can expand to respond to increased demand for skills. It is also probably important that there be sufficient uncertainty about migration outcomes, so that not everyone who invests in education migrates in the end. A related direction of research would investigate the development impact back home of skill investments aimed at the international labour market. Might such skills be ‘mismatched’ with respect to the skills most needed to promote overall development in origin countries?

For full reference list see the end of the conclusion chapter.