The qualitative differences of a heterogeneous biophysical world are seen to be analytically and practically significant, sources of unpredictability and resistance to human intention that also shape and provide opportunities for capital circulation and accumulation.

However, "brain circulation" is known as the extended definition of brain gain with an emphasis on human capital circulation across nations in the global market, benefiting both the sending and receiving nations; in addition it is considered a two-way flow of skill, capital, and technology, unlike brain drain and reverse brain drain.