Migration on a global scale is clearly linked to a multiplicity of causes that, in addition to economic factors, include conflicts, natural disasters and local political conditions. However, it is possible to pinpoint what are the main variables that underlie migratory movements between macro areas of the planet. This study analyzes the 2015 UN report data and interprets them through a gravitational model, whose independent variables are indicators of the socio-economic situation of a population. Progressively eliminating the less significant contributions, the level of education of migrants emerges as one of the most important factors