I think it depends on where they lived because if the reasons only about work then it doesn’t matter where you will get it. There is alot of vacancies around if we really want and we can reach collegues or make a new networkings. But if the problem is the sallary, and they lived in poor country but they have to feed their family then they have to move no matter what. It was only if they really want to have a better life for them and their families. For living, they also have to make sure that their family can be maintenance while they are working far away from them. Because it also cannot be accepted if they work far but their family being neglected.
For developing country, their movements are not about their family but also about the country. If they have succeed, they can help the progress of the country to be developed. They also can share the experiments to others so others can following the path and develop their family and country too. But the disadvantages is if they leaving country because feeling more comfort in other country, so their country will be developing forever because the great man has moved.
Government should make the program for making better life to their people, so everyone will help each other to gain success and stay in the country to develope theirs. It is like give and take, what you will take is depends on what you give.