Girl Power? An analysis of peer effects using exogenous changes in the gender make-up of the peer group.

The effect of a child’s peers has long been regarded as an important factor in affecting their educational outcomes. I use exogenous changes in the proportion of girls within English school cohorts to estimate the causal effect of a more female peer group. I find significant negative effects of a more female peer group on boys’ outcomes in English, particularly at age 7. Much, but not all, of this deficit is caught up by age 11, but there is still a significant negative effect present. In maths and science, all pupils benefit from a more female peer group in primary schools.