[1] http://www.amazon.com/Smartest-Kids-World-They-That/dp/14516...
P.S. I am a teacher by occupation, and I know that the research shows that teacher characteristics matter for learners. The parental involvement or value placed on education by parents mentioned in several comments that preceded mine here are important, but I deal often (just today, in fact) with trying to help parents who are involved in their children's educations but are frustrated by what's happening to their children in United States public school classrooms.
[1] http://www.amazon.com/The-Smartest-Kids-World-They/dp/145165...
http://www.amazon.com/Smartest-Kids-World-They-That/dp/14516...
This is a good blog on the state of online education: http://mfeldstein.com/
And a really good article: https://www.fastcompany.com/3062958/how-google-is-schooling-...
To answer why top Universities bet on MOOCs: this is partly an attempt to get around Education's Iron Triangle (ref: http://www.adaptivelearningworld.com/?p=110)