At 1.19 billion monthly active users, or an astounding 15% of the world’s population, Facebook is perhaps the largest voluntary collection of human data ever made. It puts into writing hundreds of actions that previously went unrecorded for masses of people, and we now have studies for which it was previously impossible to create an appropriate sample size. Now a group of data scientists have zeroed in on a trend called ‘coordinated migration,’ where at least 20% of the population of one city has moved to another city.
The trends are particularly interesting in light of global conflict and the rise of the world’s mega-cities, with a population of 10+ million. Rapidly urbanizing cities attract populations from the neighboring cities, most often within the same country. These mega-cities act as hubs that attract significant populations from specific locations. Depending on how centralized a country is, there might be a single hub attracting people from the entire country (as seen in West Africa) or a more diffuse set of hubs, as seen in South-East Asia and even more strongly in India.
The top cities might surprise you: according to data from the World Bank, Lagos, Nigeria grew 18.6% between 2000 and 2012 as a destination city, and Istanbul, Turkey was a distant second, absorbing a lot of immigrants from Eastern European countries with Turkish minorities. According to additional information from Wolfram Research, the U.S. remains a magnet for immigration from India, China and Great Britain. The teams’ visualizations are perhaps most intriguing of all, illustrating our interconnected world through the ‘leaps’ that people make over continents and oceans. Check them out below; the countries with the highest urbanization growth are highlighted in yellow.