The problem

There is hardly a country without educational inequalities based on social origin. The results of sociological research on inequality in general, international comparative studies, and some systematic comparisons between national studies, however, reveal clear differences (see inter alia, Kao and Thompson, 2003; Müller and Kogan, 2010: 252ff.; Hanushek and Wößmann, 2011). From the very beginning, the various hypotheses of the causes for cross-country differences have suggested the vital importance of educational systems, which differ considerably in terms of their institutional design both internationally and regionally. The core of the discussions on educational systems consists of a question concerning the specific effects of differentiation according to achievement (‘ability tracking’) as compared to integration with a largely common learning, possibly even up to the end of compulsory education.

Ability tracking is justified by the presumption that a homogenisation of learning environments in terms of performance and/or dispositions is advantageous – including for academically weaker pupils. The argument in opposition to such sorting is that less talented pupils could no longer benefit from the more favourable learning environment of an integrated school and would possibly perform worse due to an assignment to lower valued types of schools, entailing stigmatisation and negative self-perception. This will particularly apply if the differentiation is empirically also a matter of stratification: a vertical sorting, for example, into more academic general education in contrast to non-academic, specific or vocational education, varying in terms of the curricula's demands and the qualifications and certificates, which are connected with different levels of prestige and career opportunities (see Allmendinger, 1989: 239ff.; Meier and Schutz, 2007: 5ff.; van de Werfhorst and Mijs, 2010: 409ff.; Betts, 2011: 343ff.). The empirical evidence seems to be clear: pupils apparently display no higher achievement in cases of differentiation, but the effect of social origin, and thus educational inequality, is reinforced when compared to integration without institutional sorting. It is therefore not appropriate to refer to a trade-off between social permeability and the level of achievement in cases of a differentiated educational system. All (recent) reviews of the state of research agree on this: ‘it can be widely taken for granted that early tracking is furthermore associated with the generation of more educational inequality with particular disadvantage for lower class and migrant families’ (Müller and Kogan, 2010: 227, emphasis added).