Non-whites in the US are heavily overrepresented amongst the poor. Excluding them excludes much of the poor from the US figures, which would raise the average performance - specifically given that the author is saying that it's the kind of homes you find in places of poverty with high crime that reduce PISA scores.
Also, claims of genetic intellectual differences between the races are dead as a dodo. No real genetic difference has been found, and if there was any, it is so small that it's utterly swamped by cultural issues. Claiming that you want to cleave off a different race to 'make the comparison fair' is tantamount to saying 'blacks are intellectually inferior to whites'.
Poverty, crime, and broken homes are presented as the thesis for poor performance in school, then the author removes a large amount of those people from the US results citing this rather racist "but, genetics!" idea.
Also, claims of genetic intellectual differences between the races are dead as a dodo. No real genetic difference has been found, and if there was any, it is so small that it's utterly swamped by cultural issues. Claiming that you want to cleave off a different race to 'make the comparison fair' is tantamount to saying 'blacks are intellectually inferior to whites'.
Poverty, crime, and broken homes are presented as the thesis for poor performance in school, then the author removes a large amount of those people from the US results citing this rather racist "but, genetics!" idea.