“Although previous research has shown that homework improves students’ academic achievement, the majority of these studies use data on students’ homework time from retrospective questionnaires, which may be less accurate than time-diary data. We use data from the combined Child Development Supplement (CDS) and the Transition to Adulthood Survey (TA) of the Panel Study of Income Dynamics to explore the effects of time spent on homework while attending high school on two measures of academic achievement: high school GPA and college attendance by age 20. We find that homework time has no effect on these measures of academic achievement.”
Rønning, M. (2008). Who benefits from homework assignments? (Discussion Papers No. 566). Oslo, Norway: Statistics Norway, Research Department. Retrieved from https://eric.ed.gov/?id=EJ908287 Full text available http://www.ssb.no/a/publikasjoner/pdf/DP/dp566.pdf
If your children are so smart they can surely do some reading and research of their own. That's what I did back in prehistoric times (1960s and early 1970s). In the subjects I enjoyed I was consistently ahead of the bulk of the class and occasionally of the teachers simply because I read all the text books and spent time in the library. It was enthusiasm that drove my performance not the imposition of extra homework.