Declan Butler in Nature:
Growing concerns over an ‘invasion’ of refugees and migrants helped to elect Donald Trump and sway Brexit voters. Yet the data suggest that the situation is very different from how it is often portrayed. Researchers warn that misleading reports about the magnitude of flows into Europe and the United States are creating unjustified fears about refugees. That is undermining efforts to manage the massive humanitarian problems faced by those fleeing Syria and other hotspots.
…Refugee numbers are easier to track. The UNHCR estimates that there were 21.3 million refugees in 2015; that is only slightly higher than the 1992 figure of 20.6 million, when the global population was just two-thirds of today’s. Researchers also warn about misinterpreting estimates of international migrants — those who move for economic or other reasons. These numbers can be problematic because the most widely cited UN figures are cumulative. Guy Abel, a statistician at the Vienna Institute of Demography, has studied the dynamic flow and found that the number of people migrating has remained stable over the past 50 years. His latest estimates indicate that migration rate, as a share of global population, has dropped to its lowest point in 50 years.