Deteriorating equivalence in physical education in Sweden?: Using sibling correlation to estimate the effect of family background on grades in physical education between 2000–2017

Introduction In physical education (PE), equivalence is a central goal in welfare states around the world. In Sweden, this means that the subject of PE should be equal and that schools are to compensate for students’ different backgrounds, such as family background, socioeconomic and migration background. However, even if equivalence is a central goal, little is known about how equivalence in PE in Sweden has changed both during the last decades and in comparison to the students’ average grade from all school subjects (so-called merit value). One well-established approach to examine equivalence in educational research is to analyze the correlation between full siblings’ grades. Although this is a valuable approach to examine equivalence, no studies have used it in PE (Jansson et al., 2022). Using this approach, the aim of this study is to analyze how equivalence in PE in Sweden has changed, both over the last two decades and in relation to the students’ merit value. Methods This study includes the total population of students (N=6,961,173) that were enrolled in Swedish schools between 2000-2017 in school year 6 and 9. The method is based on analyzing the correlation between full siblings that are born within a three-year period and their annually standardized grades in PE and merit value, using variance decomposition. One main advantage with this measure is that it considers all the aspects that full siblings share (e.g., socioeconomic, upbringing, living conditions and parenting). The analysis provides information about the extent of the total variation in PE grades and merit value that are explained by the family background of the students. Results In relation to the total variation in students’ grades in PE and merit value, the proportion explained by variation between full siblings has increased between the years 2000-2017. Consequently, the results indicate that the importance of students’ family background, over the past two decades, has become more important for both students’ grades in PE and their merit value. However, the importance of family background has increased considerably more for students grades in PE, compared to their merit value. Furthermore, the largest increase in sibling correlation is found within the group of students born abroad. Discussion Preliminary findings indicate that equivalence in PE in Sweden has deteriorated between 2000 and 2017. Possible explanations are that: 1) schools, and in particular PE, has become worse at co