Migrant scientists outperform domestic scientists. The result persists after instrumenting migration for reasons of work or study with migration in childhood to minimize the effect of selection. The results are consistent with theories of knowledge recombination and specialty matching.
Franzoni, C., Scellato, G., & Stephan, P. (2014). The mover’s advantage: The superior performance of migrant scientists. Economics Letters, 122(1), 89-93.
https://doi.org/10.1016/j.econlet.2013.10.040