Do Research Expats Help Transfer Knowledge to Their Countries of Origin?

A too-often ignored aspect in discussions on migration is that migration rates are generally much higher among skilled workers and an increasing share of the total migration concerns persons holding a college degree or higher qualification. To what extent, does the depletion of human capital caused by the so-called brain drain can be compensated, in addition to the money being sent back home, by the increase of knowledge and capital flows that may result from the ties between the country of origin and expatriate communities? Answering this kind of question is rather difficult because of the lack of solid empirical evidence, and existing studies are still few and limited to specific cases. In a recent article written by Francesco Lissoni and Ernest Miguelez with technical support by Gianluca Tarasconi, these issues are addressed using a new database related to inventors residing in the United States (which is the most important destination of science and engineer expats) responsible for patent applications at the European patent Office in the period 1980-2010. The analysis considered ten countries of origin concerning inventors, including five European countries (France, Germany, Italy, Poland and Russia) and five non-European economies (China, Japan, India, Iran, South Korea).

In order to understand the extent to which the inventors who migrated to the United States help to transfer knowledge to their countries of origin, the study considered the citations obtained from patents of these inventors. More specifically, the article tries to answer two questions. First, to what extent expatriated inventors tend to cite mainly the patents of other inventors who are fellow nationals? Answering this question is useful to understand if and how researchers abroad give rise to a diaspora effect, i.e. form a cohesive, compact community that shares and disseminates knowledge in-house. Second, to what extent do the patents registered by expat inventors are prominently cited by inventors in their country of origin? The answer to this question is crucial to understand if a given country is given privileged access to knowledge produced by researchers belonging to its diaspora abroad.

Expat communities are not all the same

The results obtained show that communities of researchers abroad appear to be compact and cohesive, i.e. exhibit the so-called diaspora effect, only in the case of China, India, South Korea and Russia. Conversely, no significant effect was seen for European countries. As regards, however, the ability of expat inventors to transfer knowledge to their countries of origin, the only countries showing a net gain are China, South Korea and Russia. Putting together these two results, it appears that having a tight research diaspora, as is the case with India, is a necessary but not sufficient condition to benefit from significant knowledge transfers coming from expats. Considering the European countries, including Italy, the loss of human capital due to the outflow of researchers abroad does not seem to give rise to any offsetting effect in terms of knowledge transfer back home.

It is possible that the different demographics of various communities of research expats (relatively young if they are Asian, in comparison with European ones), as well as the difference in migration channels (through the educational system in the case of Asia and Russia, and via multinational companies in the European case ) are important factors in explaining these differences across countries. However, only a better understanding of these aspects will provide guidance to policy-makers on the most effective way to transform the brain drain into a net gain for the economies that produced these brains in the first place.