Poverty has a huge impact on American PISA scores
“Two countries with similar levels of prosperity can produce very different results,” Ángel Gurría, the O.E.C.D. secretary general, said in a statement on Tuesday. “This shows that an image of a world divided neatly into rich and well-educated countries and poor and badly educated countries is now out of date.” (New York Times, "Western Nations React to Poor Education Results," Dec. 8).
I have not yet seen an analysis of the impact of poverty on overall PISA scores (I have sent for the full set of data; they tell me it will come in ten days or so). But data available now tells us that poverty, as usual, had a huge impact on PISA reading test scores for American students. American students in schools with less than 10% of students on free and reduced lunch averaged 551, higher than the overall average of any OECD country. Those in schools with 10 to 25% of students qualifying for free and reduced lunch averaged 527, which was behind only Korea and Finland.
In contrast, American students in schools with 75% of more of children in poverty averaged 446, second to last among the 34 OECD countries.
This makes sense. Among other things, high poverty means less access to books at school, at home and in the community (e.g Krashen, 2004, The Power of Reading). Less access means less reading, and less reading means lower performance on tests such as the PISA.
The PISA data can be found on page 15 (table 6) of Highlights From PISA 2009, available on the internet.