Staff from the Institute for Educational Research at University of Jyväskylä, the Ministry of Employment and the Economy, the Ministry of Education and Culture and the Finnish National Board of Education have summarised Finland's acheivements in PIAAC. Here are the highlights:

1.  The mean literacy rate of Finnish adults is excellent by international standards. Finland’s mean score for literacy was 288 points, which is significantly better than the average score for the OECD countries (273 points). The only country to score higher was Japan.
2. Mean proficiency in numeracy in Finland is one of the best in the survey. The mean score (282 points) is substantially higher than the OECD average (269 points). Japan was the only country that exceeded Finland in proficiency in numeracy (288 points).
3. Altogether 41% of all Finns are either good or excellent at solving problems in technology-rich environments. This is well over the OECD average (34%). The only country to score higher than Finland in this domain is Sweden.

The authors do not offer an explanation, but perhaps our subscribers in Finland can offer some answers