'We don't know nearly enough about migration'

In the current issue of the scientific journal Science, which was published today, Frans Willeken, migration expert at the Max Planck Institute for Demographic Research, together with three further experts on migration, summarizes in a review article the current state of knowledge. The article appears shortly before the first World Humanitarian Summit, which has been organized by the United Nations and will take place May 23–24, 2016 in Istanbul, Turkey. The summary paints a rather soberin