University participation among women has been increasing over the last 3 decades such that now in Canada more than half of all new degrees are awarded to women. Recent research has suggested that boys are also falling behind in their grades and educational as- pirations during high school. Both grades and aspirations re ect many different individual characteristics and socio-economic circumstances. To uncover the deeper determinants of the gender gap in university participation, I use the Youth in Transition Survey to estimate a factor model based on a framework developed by Foley, Gallipoli, and Green (2014). I use that model to identify and quantify the impact of three factors: cognitive skills, non- cognitive skills and parental valuations of education (PVE). I find that all three factors play an important role in explaining both the level and the gap in university participation. The factor structure as a whole accounts for 88 percent of the gender gap, and of that the PVE factor accounts for 28 percent. This result suggests that parents play a larger role than what is implied by decompositions employing only observed determinants.