The paper examines the impact of brain drain migration on human capital formation in developing countries. Using a new dataset on emigration rates by education level, the authors find that skilled migration prospects positively affect gross human capital levels in a cross-section of 127 developing countries. However, when estimating the net effect of brain drain using counterfactual simulations, they find that countries with low levels of human capital and low skilled emigration rates are likely to experience a net gain, while countries with high skilled emigration rates and/or high enrollment rates in higher education tend to be net losers. The aggregate effect suggests that brain drain migration may increase the number of skilled workers worldwide and in developing countries, despite the overall net loss in human capital formation for individual countries. The findings highlight the complex dynamics of brain drain and its implications for human capital development in developing nations.The paper examines the impact of brain drain migration on human capital formation in developing countries. Using a new dataset on emigration rates by education level, the authors find that skilled migration prospects positively affect gross human capital levels in a cross-section of 127 developing countries. However, when estimating the net effect of brain drain using counterfactual simulations, they find that countries with low levels of human capital and low skilled emigration rates are likely to experience a net gain, while countries with high skilled emigration rates and/or high enrollment rates in higher education tend to be net losers. The aggregate effect suggests that brain drain migration may increase the number of skilled workers worldwide and in developing countries, despite the overall net loss in human capital formation for individual countries. The findings highlight the complex dynamics of brain drain and its implications for human capital development in developing nations.