In response to the recent migrant and refugee crisis, rich countries have redoubled policy efforts to deter future immigration from poor countries by addressing the “root causes” of migration. We review existing evidence on the extent and effectiveness of such efforts.
As waves of migrants have crossed the Mediterranean and the US Southwest border, development agencies have received a de facto mandate: to deter migration from poor countries. Will it work? Here we review the evidence on whether foreign aid has been directed toward these “root causes” in the past, whether it has deterred migration from poor countries, and whether it can do so.