Are foreign-born researchers more innovative? Self-selection and the production of knowledge among PhD recipients in the USA

When analyzing knowledge production, the evidence suggests that within the USA, foreign-born researchers exhibit more productivity than their domestic counterparts. Previous literature indicates that productivity differences can be explained by higher academic ability and the selection of more research-oriented fields among foreign-born. In this study, we use individual data from the restricted-access version of the Survey of Doctoral Recipients between 1995 and 2003 to extend this notion and compare knowledge production, in terms of papers presented, articles published, patent applications, and patents granted, of foreign-born and domestic PhD recipients. Our results strongly support the notion that foreign-born researchers, and especially naturalized US citizens, outperform their domestic counterparts in all four of our measures of knowledge production. We show that while aspects associated with academic training, quality of the school, occupation mismatch, and fields of study, among others, play a role in productivity differentials, they only account for a small proportion of the variability. We develop a theoretical a model to show that non-directly observable aspects associated with non-academic ability of foreign-born and a better match between the student and the PhD program, associated with differing opportunity costs of attending the program, may explain the results. Different specifications and robustness checks are conducted to provide support to our theory.