"human capital flight" is correct and usable in written English.
You can use it when referring to the mass migration of talented and skilled individuals away from their country of origin, usually for labor or educational opportunities. For example: "The government has taken steps to mitigate human capital flight by increasing access to educational opportunities at home."
Multiply that loss by millions, and one gets a sense of human capital flight from the region.
Searching for the commensurate historical parallel in terms of human capital flight, you would probably go for the time when Justinian shut down the Platonic Academy in Athens, and the philosophers took all their learning to Persia, while the Dark Ages set in for Europe.
Haque and Kim (1995) suggest that the return on human capital investment, i.e., education, can actually be negative after a certain point if it causes human capital flight.
If Trump needs to know one thing about Putin it is that he cannot survive domestically with a collapsed economy and human and capital flight without a supreme enemy, which must be the United States.
Documented effects have included human and capital flight, infrastructure destruction, and increased mortality and morbidity (Ohiorhenuan and Steward 2008).
"They were elated!" Bihar's high crime rates were often held responsible for the state's poor economic performance in the past, and particularly for the lack of a robust private sector, thanks to low external investment levels and human and financial capital flight.
First, it is common for national health systems to become targets during conflict [ 2], resulting in attacks against health workers and consequently flight of human capital (e.g. Cambodia, Mozambique, Rwanda) [ 11, 15].
In addition to flight of human capital, these include: mismatches between skills and service needs; salary distortions engendered by the influx of non-state employers; breakdown of pre-service training; lack of human resources (HR) data to inform workforce planning; lack of management capacity at different health systems levels; and underperformance of the remaining health workforce.
Capital controls limit capital flight.
Capital flight continues apace.
Human capital is lagging.
