The term "brain drain" dominates popular discourse on high-skilled migration, and for this reason, we use it in this article. However, as Harry Johnson noted, it is a loaded phrase implying serious loss. It is far from clear that such a loss actually occurs in practice
indeed, there is an increasing recognition of the possible benefits that skilled migration can offer both for migrants and for sending countries. This paper builds upon a recent wave of empirical research to answer eight key questions underlying much of the brain drain debate: 1) What is brain drain? 2) Why should economists care about it? 3) Is brain drain increasing? 4) Is there a positive relationship between skilled and unskilled migration? 5) What makes brain drain more likely? 6) Does brain gain exist? 7) Do high-skilled workers remit, invest, and share knowledge back home? 8) What do we know about the fiscal and production externalities of brain drain?