Nicole M. Fortin, Philip Oreopoulos, Shelley Phipps:

Using three decades of data from the “Monitoring the Future” cross-sectional surveys, this paper shows that, from the 1980s to the 2000s, the mode of girls’ high school GPA distribution has shifted from “B” to “A”, essentially “leaving boys behind” as the mode of boys’ GPA distribution stayed at “B”. In a reweighted Oaxaca-Blinder decomposition of achievement at each GPA level, we find that gender differences in post-secondary expectations, controlling for school ability, and as early as 8th grade are the most important factor accounting for this trend. Increases in the growing proportion of girls who aim for a post-graduate degree are sufficient to account for the increase over time in the proportion of girls earning “A’s”. The larger relative share of boys obtaining “C” and C+” can be accounted for by a higher frequency of school misbehavior and a higher proportion of boys aiming for a two-year college degree.