On Jan 30, 2011, at 10:41 AM, brad wrote:
> I think the missing variable is precisely family background
No it's not. It's very present. But it's not the only effect. Schools matter too (and the OECD points out that the U.S. system does a rather poor job of compensating for poverty, because we badly underfund schools for the poor). I suspect that culture matters too - a country that can elevate Sarah Palin to the level of political celebrity has a problem with literacy and knowledge. But that's harder to quantify.
Doug