Because social class inequality is greater in the United States than in any of the countries with which we can reasonably be compared, the relative performance of U.S. adolescents is better than it appears when countries’ national average performance is conventionally compared.
- 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.
- A sampling error in the U.S. administration of the most recent international (PISA) test resulted in students from the most disadvantaged schools being over-represented in the overall U.S. test-taker sample. This error further depressed the reported average U.S. test score.
- 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.
- A re-estimated U.S. average PISA score that adjusted for a student population in the United States that is more disadvantaged than populations in otherwise similar post-industrial countries, and for the over-sampling of students from the most-disadvantaged schools in a recent U.S. international assessment sample, finds that the U.S. average score in both reading and mathematics would be higher than official reports indicate (in the case of mathematics, substantially higher).
- This re-estimate would also improve the U.S. place in the international ranking of all OECD countries, bringing the U.S. average score to sixth in reading and 13th in math. Conventional ranking reports based on PISA, which make no adjustments for social class composition or for sampling errors, and which rank countries irrespective of whether score differences are large enough to be meaningful, report that the U.S. average score is 14th in reading and 25th in math.
- Disadvantaged and lower-middle-class U.S. students perform better (and in most cases, substantially better) than comparable students in similar post-industrial countries in reading. In math, disadvantaged and lower-middle-class U.S. students perform about the same as comparable students in similar post-industrial countries.
- At all points in the social class distribution, U.S. students perform worse, and in many cases substantially worse, than students in a group of top-scoring countries (Canada, Finland, and Korea). Although controlling for social class distribution would narrow the difference in average scores between these countries and the United States, it would not eliminate it.
- U.S. students from disadvantaged social class backgrounds perform better relative to their social class peers in the three similar post-industrial countries than advantaged U.S. students perform relative to their social class peers. But U.S. students from advantaged social class backgrounds perform better relative to their social class peers in the top-scoring countries of Finland and Canada than disadvantaged U.S. students perform relative to their social class peers.
- On average, and for almost every social class group, U.S. students do relatively better in reading than in math, compared to students in both the top-scoring and the similar post-industrial countries.
Because not only educational effectiveness but also countries’ social class composition changes over time, comparisons of test score trends over time by social class group provide more useful information to policymakers than comparisons of total average test scores at one point in time or even of changes in total average test scores over time.
- The performance of the lowest social class U.S. students has been improving over time, while the performance of such students in both top-scoring and similar post-industrial countries has been falling.
- Over time, in some middle and advantaged social class groups where U.S. performance has not improved, comparable social class groups in some top-scoring and similar post-industrial countries have had declines in performance.
Performance levels and trends in Germany are an exception to the trends just described. Average math scores in Germany would still be higher than average U.S. math scores, even after standardizing for a similar social class distribution. Although the performance of disadvantaged students in the two countries is about the same, lower-middle-class students in Germany perform substantially better than comparable social class U.S. students. Over time, scores of German adolescents from all social class groups have been improving, and at a faster rate than U.S. improvement, even for social class groups and subjects where U.S. performance has also been improving. But the causes of German improvement (concentrated among immigrants and perhaps also attributable to East and West German integration) may be idiosyncratic, and without lessons for other countries or predictive of the future. Whether German rates of improvement can be sustained to the point where that country’s scores by social class group uniformly exceed those of the United States remains to be seen. As of 2009, this was not the case.
Great policy attention in recent years has been focused on the high average performance of adolescents in Finland. This attention may be justified, because both math and reading scores in Finland are higher for every social class group than in the United States. However, Finland’s scores have been falling for the most disadvantaged students while U.S. scores have been improving for similar social class students. This should lead to greater caution in applying presumed lessons from Finland. At first glance, it may seem that the decline in scores of disadvantaged students in Finland results in part from a recent influx of lower-class immigrants. However, average scores for allsocial class groups have been falling in Finland, and the gap in scores between Finland and the United States has narrowed in each social class group. Further, during the same period in which scores for the lowest social class group have declined, the share of all Finnish students in this group has also declined, which should have made the national challenge of educating the lowest social class students more manageable, so immigration is unlikely to provide much of the explanation for declining performance.