The British economist, Paul Collier, starts his recent analysis of immigration and multiculturalism in the 21st century with a chapter on The Migration Taboo. He states that of all the social sciences the study of migration is most polemical and taboo because being seen as defending one side or another appears to have ethical and political overtones beyond the defined scope of discussion and often irrespective of evidence.

While respecting this warning, this RMMS report aims to discuss mixed migration in a balanced and evidence-based way, describing current and future trends and particularly exploring the linkages between migration and development in the Horn of Africa and Yemen region. While previous RMMS reports have often focused on protection risks and negative aspects of mixed migration flows in the region and beyond, there is a positive side to migration as well. Migration can be an effective poverty-reduction strategy and has many beneficial effects for countries of origin, destination countries and for migrants themselves.