Brain Drain

A slang term for a significant emigration of educated or talented individuals.It is also referred as human capital flight

This cause countries to lose valuable professionals i.e. departure of doctors, scientists, engineers or financial professionals who seek a better standard of living or who gets a better professioal opportunity outside their home country. When the intellect capital leaves, the home country is harmed in two ways. 

• First, expertise is lost with each emigrant, diminishing the supply of that profession. 
  
• Second, the  economy is effected as each  professional represents surplus spending units.
  

 As they earn large salaries, so their departure results in  significant decline in consumer spending in the nation.Counteracting the emigration of highly skilled personnel remains a key pursuit. But while some countries suffer the consequences of the so-called "brain drain", others are beginning to reap its potential benefits

An opposite situation, in which many trained and talented individuals seek entrance into a country, is called a brain gain; this may create a brain drain in the nations that the individuals are leaving.This is sometimes referred to as a 'brain transplant'.It  occurs when there is a large-scale immigration of technically qualified persons.