Migration Flows |
This work was produced as a collaboration between WorldPop, Flowminder and the Asian Demographic Research Institute (ADRI).
An internal migrant is defined here as an individual who has a different administrative unit of usual residence, within a given country, during the census year in comparison to five years prior to the census. Sex-disaggregated internal “interregional” migration flows, mostly between Level 1 administrative units, were estimated using 5-year migration data for 40 countries extracted from census microdata available through the IPUMSI database (Ceaușu et al., in preparation). For each country, the use of migration data collected during the 2010 round of population and housing censuses (spanning the period 2005 to 2014) was prioritized in order to produce estimates that are representative of the 2005-2010 period as best as possible. However, migration data collected during the 2000 round had to be used for 20 countries for which migration data collected during the 2010 round were not available The statistical relationships identified between the migration flows of the 40 countries and a number of geospatial, environmental, and socioeconomic factors were used to estimate internal migration flows for a total of 121 countries.
An international migrant is defined here as an individual who has a different usual country of residence in 2010 compared with 2005. Estimates of sex-disaggregated international migration flows are based on Azose & Raftery (2019) extension to the demographic accounting method proposed by Abel and Sander (2014), using the changes in UNDESA sex-disaggregated bilateral migrant stock data between 2005 and 2010 (2017 Revision).
Finally, sex-disaggregated international “interregional” migration flows were estimated by combining the country-to-country sex-disaggregated international flows with the corresponding sex-disaggregated internal “interregional” migration flows (Ceaușu et al., in preparation). Following Dennett & Wilson (2013), this was done by assuming that, in each country, the subnational spatial distribution of internal out-migrants and in-migrants is the same as the subnational spatial distribution of international emigrants and immigrants. In other words, it was assumed that in each administrative unit in the country of origin, the proportion of internal out-migrants matches the proportion of international emigrants. Similarly, it was assumed that in each administrative unit in the country of destination, the proportion of internal in-migrants matches the proportion of international immigrants.
References
Silvia Ceaușu, Dorothea Woods, Chigozie E. Utazi, Guy J. Abel, Xavier Vollenweider, Andrew J. Tatem, Alessandro Sorichetta (2019). Mapping gender-disaggregated migration movements at subnational scales in and between low- and middle-income countries - Funded by the Swiss Confederation, represented by the Federal Department of Foreign Affairs (FDFA), Peace and Human Rights Division. https://dx.doi.org/10.5258/SOTON/WP00673