According to research, homework does not increase academic performance; in fact, it may worsen it. Homework instills a bad attitude toward school and education in pupils, making them dread coming to class.
the network admins of my life have always made me acambron, ajcambro, acambro... but a first... cambrona. Spanish speakers, feel free to chuckle.
For college students, print exposure (reading for pleasure) defeats all rivals, including high school grades, in predicting wide range of knowledge of variety of subjects. Stanovich,K. & Cunningham,A.1993. Where does knowledge come from? Journal of Educational Psych 85,2:211-229.