The NEPS subunit "Social Inequality and Educational Decisions in the Life Course" focuses on the causes of educational decisions that vary by socio-structural groups, such as the choice of school at enrollment, the choice of a secondary school, the continuation of the educational career in the form of attending university or vocational training, or the participation in further vocational training. Class-specific differences in educational choices can be observed even when comparable achievements (e.g., grades, competencies, certificates) are available.

Three causes of educational inequality are distinguished: 
1. Inequality due to competency-based differences in performance (primary effects of social origin);
2. Inequality due to different decision-making patterns while keeping competencies constant (secondary effects of social origin);
3. Inequality due to systematically different recommendations and decisions of influential third parties (e.g., teachers) (tertiary effects of social origin).

Research to date shows that secondary effects are particularly strong in the German education system compared with other countries. Over the life course, educational decisions are repeatedly influenced by social origin, from parents' decisions to provide early childhood care to workers' decisions to participate in further education. Therefore, it is necessary to clarify the importance of educational aspirations, motivation, expectations of success, and evaluations of education depending on social class, and the role of class-specific differences in access to financial, cultural, and social capital in educational acquisition. 

Sociological theories offer a range of explanations for these differential decision patterns, from rational choice approaches to socialization approaches to dual-process models. Moreover, decisions may be the result of differential resource endowments in the form of financial, cultural, and social capital.