As our children head back to school again, it is useful to ask why so many are doing so poorly. It seems we’ve tried everything to improve standardized test scores among disadvantaged students, with little success.

But perhaps the answer partially lies in the home, not in the school. It turns out that children raised by single parents account for 71 percent of high school dropouts, according to federal statistics, and that children who have shared parenting after their parents separate due to divorce do considerably better.