Why Finland’s schools are great (by doing what we don’t).
Finland's schools are great because they are full of Finns, in the same way that schools with many Finns in the US do very well.Hong Kong and Singapore's schools are great because they are full of Chinese, in the same way that schools with many Chinese in the US do very well, even in poor neighborhoods:  http://articles.latimes.com/2008/jul/16/local/me-lincoln16

  To begin with, the eight students agreed on a few 
  generalities: Latino and Asian students came mostly from 
  poor and working-class families.

  According to a study of census data, 84% of the Asian and 
  Latino families in the neighborhoods around Lincoln High 
  have median annual household incomes below $50,000. And 
  yet the Science Bowl team is 90% Asian, as is the Academic 
  Decathlon team.

It is thus not likely to be the schools. It is more likely to be culture or (more controversially) genetics. But most articles don't even consider such explanations, preferring to keep looking under the streetlight for that quarter.