The migration of skilled individuals from developing countries has typically been considered to be costly for the sending country, due to lost investments in education, high fiscal costs and labour market distortions. Economic theory, however, raises the possibility of a beneficial brain drain primarily through improved incentives to acquire human capital. Our survey of empirical and theoretical work shows under what circumstances a developing country can benefit from skilled migration. It argues that the sectoral aspects of migration and screening of migrants in the receiving country are of major importance in determining the welfare implications of the brain drain. These issues, as well as the size of the sending country, duration of migration and the effect of diaspora populations, should be addressed in future empirical work on skilled migration. JEL