Are migrants more productive than stayers? Some evidence for a set of highly productive academic economists

This paper compares the average productivity of migrants (who work in a country different from their country of origin) and stayers (whose entire academic career takes place in their country of origin) in a set of 2,530 highly productive economists that work in 2007 in a selection of the top 81 Economics departments worldwide. The main findings are the following two. Firstly, productivity comparisons between migrants and stayers depend on the cohort and the type of department where individuals work in 2007. For example, in the top U.S. departments, foreigners are more productive than stayers only among older individuals; in the bottom U.S. departments, foreigners are more productive than stayers for both cohorts, while in the other countries with at least one department in the sample the productivity of foreigners and stayers is indistinguishable for both cohorts. Secondly, when we restrict our attention to an elite consisting of economists with above average productivity, all productivity differences between migrants and stayers in the U.S. vanish. These results are very robust. However, our ability to interpret these correlations is severely limited by the absence of information on the decision to migrate.