A fascinating recent paper on arXiv.org, entitled “Geo-located Twitter as the proxy for global mobility patterns” (also reported on the MIT technology review) uses Twitter to study human movement (the study is based on a dataset of almost a billion tweets). The CIRCOS image below shows the top 30 country-to-country visitor flows, as estimated by the authors. Ribbon colours indicate trip destination, so Mexico-based Twitterers visiting the US are a major category. While the US is the most common travel destination, Russia is the most common point of origin.
There’s lots more in the paper: it’s well worth a read. Twitterers may not be totally representative of the world population, but there are still many interesting conclusions to be drawn here, and an opportunity for even more interesting follow-up work.
Network diagram from Hawelka, Sitko, Beinat, Sobolevsky, Kazakopoulos, and Ratti: “Geo-located Twitter as the proxy for global mobility patterns”