Migrant remittances are a steadily growing external source of capital for developing countries. While foreign direct investments and capital market flows fell sharply in the last years due to the recession in the lower-middle income countries, migrant remittances continued to grow.
https://www.worldbank.org/content/dam/Worldbank/GEP/GEP2015a/pdfs/GEP15a_web_full.pdf
http://siteresources.worldbank.org/INTPROSPECTS/Resources/334934-1288990760745/MigrationandDevelopmentBrief24.pdf