The determinants and consequences of migration and internal displacement have a significant impact on the design of a public policy aimed at taking advantage of the strengths of the migrant workforce to enhance the productivity and competitiveness of host economies. The determinants are associated not only with the social and economic conditions of the countries / regions of origin, but also with the specialized and non-specialized migration opportunities in the host countries / regions. Likewise, the effects of migration on the families of migrants in the countries of origin reveal the importance of remittances on the labor participation of wives and the leverage of self-employment projects in the countries of origin. On the other hand, the degree of flexibility of migration policies is an essential element to adequately address problems of xenophobia based on ethnic origin and religious beliefs. The chapter makes a critical review of literature on the determinants and consequences of organized migration to determine the state of the art in specialized literature on the effects of migration in host countries and/or regions.