Understanding internal migration trends in OECD countries

Although the decline in the level of internal migration has been the focus of growing scholarly attention, little attention has been paid to countries with increasing or stable intensities. As a result, it is not clear why internal migration is declining in some countries but not in others. This paper seeks to address this gap by establishing variations in internal migration trends in 18 OECD countries and determining the economic, demographic and social factors underpinning them. We assemble a time series of annual interregional migration intensities from 1996 to 2018. We find that all non-European countries report a downward trend, whereas in Europe, eight countries exhibit an upward trend, four do not display a significant trend in either direction, and Poland shows a modest decline. We use a country fixed-effect dynamic panel data model to distinguish long- and short-term associations. The results show that a reduction in the proportion of young adults and regional inequalities decreases interregional migration whereas a rise in information technologies and net international migration increases interregional migration in the long term. Only regional income inequalities affect the intensity of migration in both the short and the long term. Although the different paces at which these factors evolve explain some of the heterogeneity in internal migration trends, they do not fully account for the downward trend in non-European countries. Panel time series are valuable for understanding internal migration trends and effort should be geared towards the inclusion of more countries, extended periods and additional explanatory variables.