U.S. K-12 education — how bad?

We frequently read about how poorly the United States does when it comes to K-12 education. Our educational system is said, based on this or that study, to be lagging behind those of other developed nations, thus placing our economic competitiveness at risk.
As with certain other metrics through which the U.S. is sometimes compared unfavorably to other countries, I always wonder whether the comparisons that find our education system lacking are “apples to apples.” In other words, do they compare how well various countries educate similarly situated populations?
Robert Samuelson sheds some light on this question in the context of a recent study of the reading skills of 15 year olds in 65 school systems around the world. It shows U.S. students doing slightly above average among the 34 relatively wealthy nations in the study. We’re well behind Shanghai and South Korea, and we trail Japan and Belgium as well. But we’re slightly ahead of France, Germany, and Great Britain.
However, the picture looks different if one examines the American scores by race and ethnicity. Non-hispanic whites in this country score as well or better than non-hispanic whites in Canada, New Zealand, and Australia – all of which are in the top ten worldwide overall. In other words, I submit, these countries rate ahead of the U.S. not because they are better educators but because they have a much more homogenous population.
The same picture emerges if one compares the test scores of Asian Americans to the test scores of students in Asian countries. Here, we remain below Shanghai, but surpass Japan and South Korea.
I don’t mean to say it’s okay that blacks and hispanics do poorly as long as non-hispanic whites do well. The achievement gap is a problem that should be addressed through expanded school choice and other reforms.
But, as Samuelson argues, there are real limits to the ability of schools to compensate for external problems such as broken homes, lack of assimilation, and indifference to education. And if the issue is how well our schools are doing compared to schools in other countries, the comparison really should be based on similarly situated student populations.