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Early Childhood Education and Care (ECEC) is believed to contribute to educational equality and to serve social inclusion and democracy. Segregation in day-care centres counteracts these aims but has hardly been researched in Germany so far. We describe ethnic/linguistic and social segregation at different regional levels (federal states as well as East and West Germany more generally) using data from the Early Childhood Education and Care Quality Study in the Socio-Economic Panel (K2ID-SOEP) and the National Educational Panel Study (NEPS). We find pronounced differences in distribution patterns of ECEC settings’ composition especially between West and East Germany and discuss the research implications of our findings.

International large-scale assessments (ILSAs) provide representative information about a population's knowledge, skills, or behaviors in certain domains and compare them across countries. In education, such surveys were first conducted in the 1960s and have since then expanded in terms of investigated domains, included countries, and observed populations. However, primary and secondary school students' competencies in core subjects are still the central fields of investigation (Kirsch et al. 2013; Strietholt et al. 2014). ILSAs in early childhood education 1 are scarcer and attract fewer countries to participate. One of the first cross-national studies in early childhood education was the longitudinal Preprimary Project (PPP) (1986-2006), which was conducted by the 1 Throughout the paper, we refer to early childhood education as defined by the International Standard Classification of Education (ISCED) Level 0. Here, early childhood education targets children below the age of entry into primary school. The respective programs are schoolbased or otherwise institutionalized and characterized by organized and purposeful learning activities outside of the family with an intentional education component. A minimum intensity and duration of at least two hours per day and 100 days a year is required (UNESCO 2012). The term preschool is used synonymously.