To paraphrase one of the commenters on this Huffington Post article, we shouldn't get discouraged about American students lagging behind other developed countries because...we're not really that developed of a country:
But a recent email exchange with Dr. David Berliner, a leading education researcher from Arizona State University, has led me to conclude that these doomsayers may actually be more Chicken Little than Paul Revere. The comparisons of American students to an international cohort may not be valid because the differences that exist between the United States and other countries make direct comparison of achievement test results more like apples to oranges. Let's look at why.
The United States has one of the highest poverty rates among developed countries, about 22 percent of our population live in poverty compared with, say, Finland and Denmark whose poverty rates are under 3 percent. Further, about half of the 40 million students in public elementary and secondary schools in the United States qualify for free or reduced lunches.
America has, by far, the greatest income inequity among developed countries as well. It also has the greatest demographic diversity, with more than 25 percent of public school students who speak English as a second language. Plus, we have among the highest rates of low-birth weight and among the worst health care among developed countries. All of these societal and economic factors have an immense impact on the over-all quality of our public education system and the test results that are used in international comparisons.