There has been lots of debate about the gender gap in education. This new longitudinal study by Gerhenson shows that American high school girls spend about an hour more per week on their homework than their male counterparts, as males spend about 15 fewer homework minutes per day than females.

One of the reasons is not what you might expected, but not without logic:

Participating in organized extracurricular activities and in paid work outside the household on the diary day are both associated with significantly less homework time.

Males spend nearly 15 fewer minutes on homework on days that they either participate in an organized extracurricular activity or work for pay outside of the household. Similarly, females who worked on the diary day performed about 20 fewer minutes of homework.

This is also related to SES:

Regarding other predictors of non-school study time, we find that high-SES students spend relatively more time on homework and that the SES gradient in homework time is steeper among males.

These results are consistent with the hypotheses that the SES gap and the reversal of the gender gap in college completion are at least partly attributable to corresponding SES and gender gaps in non-cognitive skills that originate in childhood and persist into young adulthood.

Abstract of the study:

Differences by gender in human capital investments made outside of the traditional school day may contribute to gender gaps in educational attainment, as students who fail to develop strong study habits during high school may struggle in less-structured post-secondary settings. We document robust, statistically significant one-hour weekly gender gaps in secondary students’ non-school study time using time-diary data from the 2003-2012 waves of the American Time Use Survey (ATUS) and transcript data from the Educational Longitudinal Study of 2002 (ELS). These complementary datasets provide consistent evidence of gender gaps that are explained neither by differential rates of participation in extracurricular activities, childcare, and part-time jobs, nor by differences in advanced course taking, past academic achievement, school quality, or cognitive ability.