Girls outperform boys in school. We investigate whether the gender performance gap can be attributed to the fact that the teacher profession is female dominated, that is, is there a causal effect on student outcomes from having a same-sex teacher? Using data on uppersecondary school students and their teachers from the municipality of Stockholm, Sweden, we find that the gender performance differential is larger in subjects where the share of female teachers is higher. We argue, however, that this effect can not be interpreted as causal, mainly due to teacher selection into different subjects and nonrandom student-teacher matching. Exploring the fact that teacher turnover and student mobility give rise to variation in teacher's gender within student and subject, we estimate the effect on student outcomes of changing to a teacher of the same sex. We find no strong support for our initial hypothesis that a same-sex teacher improves student outcomes.

In this paper I use a rich dataset in order to observe each student over time in different subjects and courses. Unlike most peer studies, I identify the peers and the teachers that each student has had in every classroom. This enables me to handle the simultaneity and selection problems, which are inherent in estimating peer effects in the educational production function. I use a value-added approach with lagged peer achievement to avoid simultaneity and extensive fixed effects to rule out selection. To be specific, it is within-student across-subject variation with additional controls for time-invariant teacher characteristics that is exploited. Moreover, I identify students that are attending classes in which they have no peers from earlier education which otherwise could bias the result. I find positive peer effects for the average student but also that there is a non-linear dimension. Lower-achieving students benefit more from an increase in both mean peer achievement and the spread in peer achievement within the classroom than their higher-achieving peers.JEL classification: I2

No abstract