Brain drain or human capital flight could be geographical, industrial or organizational. 

why don't you want to allow people to go for greener pastures?  Maybe there is a problem with the systems (e.g. health system) at home. In Fiji people who receive funding for their education have to work for a time which is as lomg as their scholarship in the country. After that they can go their own ways. Many medical people leave to country for greener pastures, and the government brings in medical professionals from India and the Philippines. Also one might need to look if the country educates more than enough professionals and then it is even an advantage when some leave lowering the competition and frustration (and violence) people have who are well educated and don't find jobs that match their qualification........

So emigration i snot only brain drain, it also has much positive aspects, also often people, after being away fro some time, return to their countries and bring in skills, capital and economic activities. While they are away they often send money back in form of remittances........

so it is not only brain drain, but also brain gain.....