Largely due to a lack of data.
Problem: countries measure migration flows in different ways.
Harmonisation only for Europe, e.g. IMEM
Widely captured in population censuses.
Country of birth != country of current residence.
UNPD released global bilateral dataset in 2013.
Accumulative measure that cannot capture recent trends.
Guy Abel & Nikola Sander.
In Science; 28 March 2014; vol 343: 1520-1522.
UN stock data
static snapshot of
1990, 2000, 2010
Our flow estimates
1990-95 to 2005-10
About 0.6 % of world population have moved over 5-year periods since 1995.
W & S Asia
East & SE Asia
Quantifying Global International Migration Flows.
Abel & Sander, 2014. In Science, Vol. 343, pp.1520-22.
"The Global Flow of People"
Interactive data visualisation
A collection of our circular migration plots