This report examines the ways in which socioeconomic (SE) factors affect educational disadvantage. As a starting-point SE could be understood as a set of structural factors that influence education and could cause disadvantages for groups of children, youths and adults. Since socioeconomic disadvantage (SED) is a very complex concept, we will present a more extensive working definition. Official perceptions of SED as well as research perspectives will be discussed. SED has intersectional dimensions and these are explored here and in the other thematic reports1. There are several different factors used to measure socioeconomic conditions. Common ways of assessing SED can include parents’ educational level, social background, living conditions and social heritage. In Eurostat, parents’ educational level, living conditions, and income are measured together with other variables such as gender and ethnic group, in a multi-dimensional structure, in order to compile a comprehensive definition of SE. Although socioeconomic circumstances have an important effect on young people’s school careers, the concept of SE is not formally and uniformly defined in relation to education in EU reports and statistics.