From the National Bureau of Economic Research come results of a web-based survey of 17,182 corresponding authors in 16 countries from four fields during 2011:[1]

The abstract goes on to say:

Switzerland has the largest percent of immigrant scientists working in country (56.7); Canada, and Australia trail by nine or more percent; the U.S. and Sweden by approximately eighteen percent. India has the lowest (0.8), followed closely by Italy and Japan. The most likely reason to come to a country for postdoctoral study or work is professional. Our survey methodology also allows us to study emigration patterns of individuals who were living in one of the 16 countries at age 18. Again, considerable variation exists by country. India heads the list with three in eight of those living in country when they were 18 out of country in 2011. The country with the lowest diaspora is Japan. Return rates also vary by country, with emigrants from Spain being most likely to return and those from India being least like to return. Regardless of country, the most likely reason respondents report for returning to one’s home country is family or personal.

My own attention was drawn to those countries that had both a low frequency of acquisition of overseas researchers and low a low frequency of ‘exporting’ their own researchers. IEEE Spectrum magazine had a similar thought: ‘Japan is the most insular country surveyed, exchanging relatively little scientific talent with the rest of the world.
’[2] Brazil and Spain also strike me has having low percentage ‘brain flows’.

IEEE Spectrum notes as an aside: ‘China wasn’t surveyed: The researchers tried but were unsuccessful in administering the survey to scientists there.’


1. Unfortunately with the abstract doesn’t say what fields were examined. The paper, whilst cheaper than most at $5 is behind a paywall.

2. I suspect that ‘with the rest of the world’ would more accurately read ‘of the 16 countries presented’.

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