Free migration creates a number of benefits for the people who choose to remain in countries that are net sources of migrants. Some important benefits are listed below:

• Ghosts versus zombies: When certain poor countries experience a contraction of their economies, then it may make economic sense for them to lose some population as economic opportunities within those areas have declined. If people are free to leave, these places become ghosts of their past selves: doing fine, but not thriving. This is regrettable, but not as bad as the alternative: if people aren’t allowed to leave, the places become “zombies” with terrible living conditions. This line of argument was developed by Lant Pritchett in his book Let Their People Come. See also emigration as disaster relief.
• Remittances sent by migrants to their family, friends, and local communities, together constitute a much larger fraction of global financial flows than all foreign aid.
• Incentives for human capital development: With the option of migrating to a country where high-paying high-skilled jobs are available, people may pay more attention to developing high skills. Some of these people may ultimately choose not to migrate for personal or family reasons.
• Exit and competitive government: The threat of exit leads to more competitive government. Rulers who know that their subjects can quit are more constrained in the policies they can adopt.