Where everyone in the world is migrating—in one gorgeous chart
These flows represent 75% of human migration from 2005-2010. (NB only flows over 50,000 are displayed.) Circos/ Krzywinski, M. et al.
It’s no secret that the world’s population is on the move, but it’s rare to get a glimpse of where that flow is happening. In a study released in today’s Science, a team of geographers used data snapshots to create a broad analysis of global migrations over 20 years.
The study was conducted by three geographic researchers from the Wittgenstein Centre for Demography and Global Human Capital in Vienna. The researchers presented their data in five-year increments, from 1990 to 2010. Their research is unique, because it turned static census counts from over 150 countries into a dynamic flow of human traffic.
Migration data is counted in two ways: Stock and flow. “The stocks are the number of migrants living in a country,” says Nikola Sander, one of the study’s authors. Stock is relatively easy to get—you just count who is in the country at a given point of time. Flow is trickier. It’s the rate of human traffic over time.
Keeping accurate account of where people are moving has stymied the UN, and researchers and policy-makers in general, for a while. The European Union keeps good track of migrant flows, but elsewhere the data are sparse. Static measurements are plentiful, but it is hard to use them to get a picture of how people are moving on a broad scale, because each country has its own methodology for collecting census data.