世界发展银行-A-Reappraisal-of-the-Migration-Development-Nexus---Testing-the-Robustness-of-the-Migration-Transition-Hypothesis_40页_1mb

A Reappraisal of the Migration-Development Nexus: Testing the Robustness of the Migration Transition Hypothesis

Core Content

This paper re-evaluates the migration transition hypothesis, which posits an inverted U-shaped relationship between a country's level of economic development and its emigration rates. The hypothesis suggests that emigration initially increases with development but eventually declines after a certain turning point. The study uses a comprehensive global panel dataset covering 180 origin and destination countries over a 50-year period (1970–2020), making it the most extensive dataset used to test this hypothesis to date.

Main Points

• Migration Transition Hypothesis: This hypothesis claims that as a country develops, its emigration rates first increase and then decrease. It is based on the idea that both migration capabilities and aspirations change with development.
• Empirical Testing: The study employs a gravity-migration model with fixed effects and a Poisson Pseudo-Maximum-Likelihood estimator with High-Dimensional Fixed Effects (PPML-HDFE) to account for the high proportion of zero migration flows and reduce bias.
• Nonlinear Relationship: The results confirm the existence of an inverted U-shaped relationship between development and emigration in a cross-country (panel) setting. However, this relationship is not interpreted as causal.
• Robustness of Results: The findings are robust to the inclusion of additional control variables, alternative time subsamples, and interaction terms. The study also includes a broader set of migration corridors, not just flows to OECD destinations.
• Policy Implications: The paper suggests that development programs can simultaneously promote economic growth and reduce emigration, challenging the traditional view that development aid is ineffective in reducing emigration.

Key Findings

• No Causal Link: The study finds that while an inverted U-shaped relationship exists between development and emigration, it cannot be interpreted as a causal link. The migration hump is more likely driven by cross-sectional patterns rather than a longitudinal causal process.
• Subsample Analysis: For a subsample of 44 countries that transitioned from low-income to middle-income status, emigration rates declined with development, contradicting the hypothesis.
• Migration Capabilities and Aspirations: Migration capabilities (MC) are expected to increase with development, following an S-shaped curve, while migration aspirations (MA) are likely to follow an inverted U-shape. These factors together predict the migration transition life cycle.
• Data and Methodology: The paper uses a large panel dataset that includes all bilateral migration flows, not just to OECD destinations, and applies a more sophisticated estimation technique to reduce bias and improve accuracy.

Key Information

• Data Sources: The dataset is compiled from the World Bank and UN databases, including migrant stock data from 1960 to 2020.
• Timeframe: The study covers a 50-year period (1970–2020), with 2019 used as a proxy for 2020.
• Methodology: The gravity-migration model is used, incorporating fixed effects for origin, destination, time, and country-pair. The study also tests for non-linear relationships using linear and squared GDP per capita terms.
• Limitations: The paper acknowledges that the presence of endogeneity and the challenge of including origin-time fixed effects remain, which limits the ability to establish a causal relationship.
• Comparisons with Previous Work: The paper differs from prior studies in its use of a more comprehensive dataset, its inclusion of all migration corridors, and its application of the PPML-HDFE estimator.

Conclusion

The migration transition hypothesis is not supported by the findings of this study. While an inverted U-shaped relationship between development and emigration is observed in cross-country data, this does not imply a causal link. The study highlights the importance of considering both economic and non-economic factors in migration decisions and suggests that development programs can effectively reduce emigration from low-income countries if they promote local economic development. The results have significant implications for development policy and international migration strategies.