A thread on my new working paper ‘Why U.S. Immigration Barriers Matter for the Global Advancement of Science’ with @_RuchirAgarwal, @inaganguli
and Geoff Smith http://ftp.iza.org/dp14016.pdf  1/N

Prior research has shown that immigrants make disproportionate contributions to U.S. innovation (among many others, see https://www.mitpressjournals.org/doi/abs/10.1162/REST_a_00283 ) 2/N

But how does U.S. migration policy affect innovation globally? To answer this question, we use novel survey data and hand-curated life-histories of International Math Olympiad (IMO) medalists 3/N

If migration has no effect on an individual’s scientific productivity, then migration policy hardly matters for the global advancement of science 5/N

However, comparing individuals who had similar talent in teenage years, we find that that migrants to the U.S. are up to six times more productive than stayers or migrants to other countries 6/N

Many of the world’s most talented youngsters – especially in developing countries - aspire to study in the U.S but are unable to do so, primarily due to financing constraints 7/N

By addressing this financing constraint, more scholarships for top talent could accelerate science and innovation globally. 8/N

We are grateful to the IMO community for their help in disseminating and filling the survey and to @peteyreplies, @mileskimball, @YanboWang18 and @dmckenzie001 for insightful discussions and to @MaxCRoser and @ATabarrok for bringing attention to our earlier work in this area.

My thinking on these issues was heavily influenced by the research of Megan MacGarvie, @m_clem and @william_r_kerr , among others. 10/N