The first talk entitled "Highly differentiated but still not the same results. Explaining differences in educational achievement between highly differentiated educational systems with general and vocational training", a joint project with Tijana Prokic-Breuer, referred to the differences within the relatively similar educational systems in the two parts of Belgium as well as in the Netherlands, Austria, the German-speaking Swiss Cantons and the German Länder in order to explain the high scores of Flanders and the Netherlands in the international PISA tests. His findings indicate that effects related to the individual, the school and the specific school-system may explain the Dutch results but not those in Flanders. However, even after controlling for individual, school and school-system variables, large differences in scores between the analyzed educational systems still persist.

His second talk entitled "The differences between the educational performance of daughters of migrants and native female pupils and that of sons of migrants and native male pupils in PISA 2009. Origin and destination effects", a joint project with Nils Kornder, presented preliminary results on the gap between children of immigrants with different origins and the native pupils by gender in different destination countries.