Martin Carnoy and Richard Rothstein, research associates at the Washington-based Economic Policy Institute, have no respect for American cultural and political tradition. Their latest paper challenges one of our most cherished beliefs, that foreigners are threatening our future by producing much better schools.

People like me sometimes exploit this fear of global inferiority. To grab reader attention, I have pointed out, as U.S. business leaders and political candidates do, how far behind parts of Europe and Asia our students are in international tests. Carnoy, also a Stanford Graduate School of Education professor, and Rothstein undermine that argument by examining the test databases and discovering that when student results are broken down by social class, our schools are doing comparatively better than we thought.

Because, in every country, “students at the bottom of the social class distribution perform worse than students higher in that distribution, U.S. average performance appears to be relatively low partly because we have so many more test takers from the bottom of the social class distribution,” they write in their report, titled “What do international tests really show about U.S. student performance?”

They say “if U.S. adolescents had a social class distribution that was similar to the distribution in countries to which the United States is frequently compared, average reading scores in the United States would be higher than average reading scores in the similar post-industrial countries we examined (France, Germany, and the United Kingdom), and average math scores in the United States would be about the same as average math scores in similar post-industrial countries.”

Having a higher proportion of poor people is nothing to brag about. Our efforts to get more people into better jobs have not been as effective as we would like. But that difference means our lower scores should not be blamed so much on our schools.

Low-income children around the world perform worse than high- and middle-income children on average in reading and math. And, if you look closely, Carnoy and Rothstein say, you see our poor kids getting better. “The performance of the lowest social class [of] U.S. students has been improving over time,” they write, while the performance of such students in both top-scoring and similar post-industrial countries elsewhere “has been falling.”

The scholars say they also found a mistake in the calculation of U.S. scores in the Program for International Student Assessment test in 2009. Students from the most disadvantaged schools were over-represented in the testing, aggravating the distortion in our average scores caused by our relatively large number of low-income students.

The full report reveals the exhaustion and frustration of Carnoy and Rothstein’s journey into the deep jungles of PISA data. The quick official reactions to these reports, such as U.S. Education Secretary Arne Duncan calling the 2009 PISA results “disturbing . . . for America,” stick in our minds. The deeper analysis weeks later makes less of an impact. “Analysis of the international database takes time,” the scholars say. The database’s complexity and size is so great that the two scholars so far have been able to analyze only six other countries besides the United States.

Trying to compare one country’s poverty rate with another’s, when the politically influenced measurements often differ, makes their work that much harder. Carnoy and Rothstein decided the best method was to use the data in the report that gives the number of books in the homes of the 15-year-olds who take the PISA. “Children in different countries have similar social class backgrounds if their homes have similar numbers of books,” they say.

By their reckoning, a fairer calculation of the PISA data would raise the United States from 14th to sixth in reading and from 25th to 13th in math. We should do better, but in the meantime, we should not exaggerate our failings as much as we have.