The Diffusion of International Migration in Cities and Rural Areas of Developing Countries

Emigration concerns a growing number of developing countries, which have experienced a fast pace of urbanization since 1960. Yet we lack evidence about the interlinkages between the two phenomena. Should governments expect large-scale emigration, as ongoing urbanization increases people's aspirations and capabilities to move? We analyze rates of emigration (i.e., movements crossing national borders) from different tiers of the urban hierarchy observed in 40 developing countries spanning the entire spectrum of urbanization. Estimates are obtained by demographic analysis of population censuses fielded between 1970 and 2017. Remote sensing products ensure an internationally consistent definition of cities. Statistical modelling is used to summarize global trends in emigration over the course of urbanization. Results reveal that the propensity to move abroad diffuses down the urban hierarchy. In early stages of urbanization, emigration rates are highest in cities, especially in the largest ones, but subsequently decline. Rural areas exhibit a lagged increase in emigration, first in more densely populated settlements, in the cities’ hinterlands and border areas, and eventually in the sparsely populated and remote countryside. In late stages of urbanization, rural emigration tends to plateau or increase again. There is evidence of a decline only in the remote countryside. Yet the rural rates of emigration remain consistently below the peak levels observed in cities. We interpret these findings with reference to the subnational diffusion of development and discuss implications for international migration and urbanization trends in developing countries.