Finland should have no correlation here, as all the schools are free and you get an allowance from the government for the duration of your studies. Unfortunately it turns out a high income correlates well with having an advanced degree, and a parent with an advanced degree correlates well with a child who has one.

Which results in a situation where the higher socio-economical status of your parents makes you much more likely to have an advanced degree, even though there should be no correlation.