That is a bit silly. In any given country most who can leave choose to stay. Even in country with a very high per capita rate most people will stay. People will leave and return after a few years. Many people are better off in many ways staying. If you have capital it goes further in a poorer country. Your income might be lower in absoluter terms but low costs might mean you have a better lifestyle. Other people leaving might make your skills rarer, so you have well paid and secure employment. You might have connections. You may not want to leave family, friends and a familiar environment.