'The Human Flight and Brain Drain Indicator considers the economic impact of human displacement (for economic or political reasons) and the consequences this may have on a country’s development. On the one hand, this may involve the voluntary emigration of the middle class – particularly economically productive segments of the population, such as entrepreneurs, or skilled workers such as physicians – due to economic deterioration in their home country and the hope of better opportunities farther afield. On the other hand, it may involve the forced displacement of professionals or intellectuals who are fleeing their country due to actual or feared persecution or repression, and specifically the economic impact that displacement may wreak on an economy through the loss of productive, skilled professional labor.'