What are the possible economic impacts of mass emigration from a certain country? Especially if that country is less developed?

Mass emigration from a country can cause brain drain and a lack of innovation.

Explanation:

Mass emigration can be a problem for less developed countries because the best and brightest in their society will seek out opportunities to study abroad and to stay abroad when they establish their careers since there are more opportunities and resources in more developed countries.  People with good engineering skills from India or Pakistan for example might seek opportunities elsewhere because the average salaries for someone with their skills are higher elsewhere. This will have a negative effect potentially on the home society but the most innovative people will seek out better opportunities elsewhere and domestic businesses and industries will not benefit from their know-how and drive. It can also negatively impact the tax base for the state if those people with the most potential to earn and be successful are leaving the country at a steady pace.  

answer; develops policy;

answer; southeast asians in the u.s.'