"Yes. Parents and really not much else but parents. They care the only thing that scale."

I would claim government policies scale up to the limit within the borders of the said country. What effect they may have depends, but most good stuff in the daily lives of ordinary people in industrialized countries owes quite a lot to government policies (public schools, no child labour, etc).

Great teacher don't scale but improving teachers education thus moving the average more towards "great" does.