[rayiner]

That’s just because Americans are richer across the Board than Japanese. But would we expect PISA scores to track absolute income across different developed countries? I don’t think that follows. For example, Sweden’s median household income (PPP) is 2.6x higher than Poland’s. But the two countries had very similar scores on the 2018 PISA: http://hechingerreport.org/what-2018-pisa-international-rank...

[diogenescynic]

I think one of the biggest factors comes down to single parent vs intact families.

[chongli]

Sweden has the highest proportion of single-parent households at 34% whereas Poland is near the bottom at 9% [1].

[1] https://ec.europa.eu/eurostat/web/products-eurostat-news/-/e...

[peterfirefly]

"Single-parent households" in Scandinavia doesn't mean the same thing as it does in most of the world. There is usually still a high degree of coparenting.

[0xDEAFBEAD]

One possible synthesis is that the high incomes in Sweden make up for the high number of single-parent households.

[diogenescynic]

I almost noted in my prior comment that income is the second biggest factor but left that out. Totally agree that income is a big part of the equation. I also bet because it's Sweden it also has to do with public services like childcare being available.

[tankenmate]

I'm interested; do you have any good stats for that?

[diogenescynic]

I am on my phone but you can Google and find lots of data that shows dual parent/intact families correlate positively with a bunch of other factors like income, college graduation, etc. More parents=more resources. More resources is generally better than less. Having kids myself, I can barely imagine being able to do it by myself... and even if I could it would certainly be to a lesser quality.