Can a brain drain be good for growth in the source economy?

"This paper analyzes the interaction between income distribution, human capital accumulation and migration. It shows that when migration is not a certainty, a brain drain may increase average productivity and equality in the source economy even though average productivity is a positive function of past average levels of human capital in an economy. It is also shown how the temporary possibility of emigration may permanently increase the average level of productivity of an economy." excerpt