Grade retention has been controversial for many years. On the one hand, a practise of retaining in grade those students making slow progress might facilitate instruction by making classrooms more homogeneous academically. On the other hand, grade retention might harm low achieving students by limiting their learning opportunities. Research results on the effects of grade retention on academic achievement show predominantly more negative than positive effects for this pedagogical treatment. Jimerson (2001) provides a systematic review and meta-analysis of 20 studies including outcome variables (i.e., achievement and socioemotional adjustment), age or grade of retained population, matched or controlled for variables in analyses with comparison groups, and the overall conclusion regarding the efficacy of grade retention. Of the 20 studies comparing retained students with a matched control group, the authors of 16 (80%) concluded that grade retention is ineffective as an intervention for academic achievement and socioemotional adjustment. These summary of studies published between 1990 and 1999 is consistent with past literature reviews from the 1970s and 1980s (Holmes, 1990). In contrast to the number of international studies on effects of grade retention, only a few studies are done with students from Germany. This is remarkable because grade retention is practised in Germany more often than in other OECD countries (OECD, 2004). Therefore, this study analysis the effect of grade retention after the 9th class on mathematics achievement in Germany: how much more or less class repeaters would have been learned, on average, had they been promoted to the 10th grade rather than retained.

The sample comprises N = 6699 students from an additional study of PISA 2003 in Germany (Prenzel, Carstensen, Schöps & Maurischat, 2006). The data survey was carried out in 2003 in the ninth grade and then again after one year in 2004. 6339 students were promoted to the 10th grade, and 360 students were retained in the 9th grade. In the data analysis we apply the technique of propensity score matching. This method focus on the comparability of the treatment group (grade retention) and the comparison group in terms of preintervention variables (e.g. SES, cognitive ability, school grades, and mathematics competence). To answer our research question we compared the average achievement in mathematics at the second measurement between the class repeater and the matched comparison group (students who were promoted to the 10th grade).

With our first analysis we find no evidence that repeating the 9th grade improves the increase in mathematics competence compared to the matched group of students that have been promoted. The findings suggest that intervention approaches other than grade retention are needed to better promote school achievement.