Silhouette of people with luggage walking in a row
Globalization has facilitated physical mobility, enabling international migration to increase from 92 million in 1960 to 244 million in 2017. Traditionally, rising migration flows have been attributed to a lack of economic development in origin countries. Would-be migrants, the argument goes, decide to move primarily in search of higher wages and income abroad.
A competing hypothesis on the migration-development relation
The “migration transition hypothesis,” first set forth by Wilbur Zelinsky in his seminal paper on the subject (1971), provided a more nuanced picture. Out-migration (emigration) first increases with development in a country until a certain turning point, after which it gradually recedes. Several scholars found empirical evidence for this, using mainly cross-sectional data (De Haas, 2010; Clemens, 2014; Dao et al., 2018). This suggests that in low-income countries economic development leads to more people using their increased financial capacity to migrate abroad, potentially eroding the country’s human capital and thus hindering its ability to develop sustainably.
What do we find empirically?
In a new working paper (Berthiaume et al., 2021), we empirically test the migration transition hypothesis’ main prediction regarding the link between development and emigration. We do this by testing a migration version of the gravity model on a global bilateral panel dataset including 180 origin and destination countries and covering every decade in the 1970-2020 period. The dataset was constructed by merging the World Bank’s Global Bilateral Databases (Özden et al., 2011) with the United Nations Department of Economic and Social Affairs’ Trends in International Migrant Stocks data (2019).
At first sight, estimating our model on the complete time and country sample appears to confirm the migration transition hypothesis that the relationship between economic development and migration follows an inverted U-shape. The result appears robust to the inclusion of various control variables such as socio-economic factors, as well as estimating it on alternative time periods. These findings are in line with other recent studies on the topic (e.g., Dao et al., 2018; Benček and Schneiderheinze, 2019).
However, it is unclear whether this inverted-U relationship between increasing economic development and emigration is due to fundamental differences between countries, or whether the relationship also holds for an individual developing country over time. To elucidate this, we perform our analysis using only a subsample of countries that transitioned from low-income to middle-income status (using the World Bank’s income classification). From this analysis, we find that the evidence for the migration transition hypothesis disappears. For a subsample of 44 countries, we find that, as development rises, emigration declines over time Accordingly, while the inverted-U-shaped relationship can be found in cross-country panel data, it does not seem to hold for individual countries over time. It is therefore likely that the inverted-U relationship is driven by cross-country differences and does not represent a link between development and emigration that holds for any given country over time. This is in line with the recent paper by Benček and Schneiderheinze (2019).
However, China and India were excluded from this subsample—because their large size overshadows the results for the other countries. When we include India and China in the sample, we do not find any relation between emigration and development levels. This suggests that both these countries, with their high growth rates and particular country characteristics, experience different emigration and development dynamics, and emigration decisions are not correlated with development levels.
Policy implications of our findings
Our findings put the validity of the migration transition hypothesis in doubt. The differences in emigration rates are likely caused by fundamental differences between countries in different income categories. This has implications for the existing policy interpretation of the link between economic development and emigration, as it suggests not only that development programs foster local economic development but that they also reduce brain drain from low-income countries, thereby reinforcing a country’s development. Inclusive and sustainable policies in low-income countries that allow individuals to reap improved economic opportunities at home can reduce outmigration and support faster development.
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