The Bilateral Migration Flows to OECD Countries: A Gravity Model Analysis Using Poisson Pseudo-Maximum Likelihood Estimation
Abstract
Background and Purpose: International migration has become one of the most important challenges in global economic and social policy. However, the existing migration literature predominantly emphasizes economic determinants, such as income disparities and employment opportunities, while giving limited attention to non-economic drivers. This study addresses this gap by examining bilateral migration flows to Organization for Economic Co-operation and Development (OECD) countries using an extended gravity model framework that integrates economic and non-economic determinants of migration. Specifically, the analysis incorporates employment, education, population, trade openness, gross domestic product (GDP), foreign direct investment, taxes, political instability, inequalities, climate change, cultural differences, language similarities, and traditional gravity factors.
Methods: Using panel data on bilateral migration flows to OECD countries over the period 2000–2024, the study employs the poisson pseudo-maximum likelihood estimator to address heteroskedasticity and zero migration flows, while the Hausman test is used to distinguish between fixed- and random-effects specifications.
Results: The empirical findings reveal that economic opportunities in destination countries, particularly higher GDP, employment prospects, and trade openness, remain significant pull factors shaping migration flows. At the same time, political instability, inequalities, unemployment, and climate-related pressures in countries of origin serve as major push factors. The results further indicate that cultural proximity, a common language, and geographic proximity significantly facilitate bilateral migration to OECD economies.
Conclusion: This study contributes to the migration literature by extending the traditional gravity model to incorporate multidimensional determinants of migration beyond purely economic explanations. The findings provide important policy implications for OECD and origin countries in designing migration, labor market, and sustainability policies that account for the growing interaction between economic, socio-political, environmental, and cultural drivers of migration.
