Brain drain

Human capital flight refers to the emigration of highly skilled or well-educated individuals. Research is mixed as to whether there are net benefits, a "brain gain", or net costs, a "brain drain", to human capital flight for the sending country.

There are several types of human capital flight:

As with other human migration, the social environment is often considered to be a key reason for this population shift. In source countries, lack of opportunities, political instability or oppression, economic depression, health risks and more contribute to human capital flight, whereas host countries usually offer rich opportunities, political stability and freedom, a developed economy and better living conditions that attract talent. At the individual level, family influences (relatives living overseas, for example), as well as personal preferences, career ambitions and other motivating factors, can be considered.

The term "brain drain" was coined by the Royal Society to describe the emigration of "scientists and technologists" to North America from post-war Europe. Another source indicates that this term was first used in the United Kingdom to describe the influx of Indian scientists and engineers. There are also other relevant phrases, "brain circulation" and "brain waste". Although the term originally referred to technology workers leaving a nation, the meaning has broadened into "the departure of educated or professional people from one country, economic sector, or field for another, usually for better pay or living conditions".

Given that the term brain drain is a pejorative and infers that skilled emigration is bad for the country of origin, some scholars recommend against using the term in favor of more neutral and scientific terms. After all, research indicates that there may be net human capital gains, a "brain gain", for the sending country in opportunities for emigration.

After Justinian closed the Platonic Academy in AD 529, according to the historian Agathias, its remaining members sought protection from the Sassanid ruler, Khosrau I, carrying with them precious scrolls of literature, philosophy, and to a lesser degree, science. After the peace treaty between the Persian and the Byzantine empires in 532 guaranteed their personal security, some members of this group found sanctuary in the Pagan stronghold of Harran, near Edessa. One of the last leading figures of this group was Simplicius, a pupil of Damascius, the last head of the Athenian school. The students of an academy-in-exile may have survived into the ninth century, long enough to facilitate the Arabic revival of the Neoplatonist commentary tradition in Baghdad.

...
Wikipedia