How can welfare regime and production regime theories explain differences in schools’ ability grouping policies? A comparative study using the PISA school survey

Research evidence is mixed on the consequences of ability grouping policies, but most research has found an overrepresentation of disadvantaged social demographics in low‐ability groups. However, researchers have neglected to explain why ability grouping policies vary between countries. Departing from welfare regime theory, our study aimed to explain schools’ ability grouping polices. For data, we used the principal survey from PISA 2022 sampling approximately 9000 schools in 34 countries. As the explanatory variable, we used welfare regimes, and as the outcome, we analysed schools’ ability grouping policy (a) within the school or (b) within the class. For analysis, we reported descriptive statistics, correspondence analysis and multilevel ordinal regression (adjusting for school demographics). In support of our predictions, we found large differences in ability grouping policies within school between welfare regimes (social democratic welfare regime vs. liberal regime). For ability grouping within the class, we found only meagre differences between social democratic regime compared with conservative regime. In contrast to our predictions, ability grouping within the class seems to be driven by school demographics rather than welfare regimes. As a sensitivity check, we compared welfare regimes with production regimes as in Varieties of Capitalism (VoC or production regime theory; Liberal vs. Coordinated Market Economy). The result suggests that VoC offers an alternative explanation that supplements that of welfare regimes. We conclude that our study both agrees and disagrees with the theory of welfare regime and its alternative (i.e. VoC). Finally, we discuss the wider implications of our findings for educational research.