If there's one thing Americans know about international tests, it's this: we aren't very good at them.
In 2012, the last time 15-year-olds from 65 countries and economies took an international math test, the US ended up ranked far from the top — particularly in math, where they were 27th of 34 countries. (The rankings aren't an exact science; the US could be ranked anywhere between 23rd and 29th, according to the Organization for Economic and Community Development.)
These results don't do much to inspire pride in the American school system. But how much do they matter for the economic future? How educated a country's citizens are appears broadly to predict how economically successful it will be. On the other hand, US students have never fared particularly well on international comparisons, and there's little evidence that has held the economy back before.
The questions US students can't answer
The test most commonly used to compare students' abilities is the Programme for International Student Assessment, or PISA. The tests have been given to a sample of students from participating nations every three years since 2000, when PISA debuted with a reading test.
The PISA tests aren't like the standardized tests that most students are used to. Those tests are supposed to measure, more or less directly, what students have learned — hence the phenomenon of "teaching to the test."
PISA, on the other hand, measures how well students can apply the skills they're supposed to learn at school in real life.
For math problems, that means many involve diagrams; quite a few questions aren't multiple-choice but require students to fill in their own answers. Here are some of more straightforward math problems students have to solve:
Not all international tests are structured this way. Another test of math and science skills, the Trends in International Mathematics and Science Study, is supposed to measure what students have learned in the classroom. The United States fares better in the international rankings on those tests.
Do better test scores predict a better economy?
The PISA scores suggest American students aren't particularly good at real-world math, or at least at the problems they're tested on. But education policy doesn't usually exist in a vacuum. Lately, it's been part of an economic argument: for the US to stay competitive, American students need to learn more than they do now.
Eric Hanushek, a Stanford economist who researches cognitive skills and economic growth, has estimated that a 25-point gain on PISA over 20 years would add $44 trillion to the US economy over the same time period. Hanushek's analyses have found that cognitive ability has a powerful impact on economic growth. The conclusion is that improving cognitive skills would boost growth rates.
In practice, though, American students have never fared particularly well when compared internationally. The first big international test of math and science skills, in 1964, compared the US to 11 other countries, including Finland, Germany and Australia. The US ended up ranked 11th out of 12th, according to a statistical analysis by Tom Loveless of the Brookings Institution.
Over the next decade, as those 13-year-olds graduated and hit the labor market, productivity in the US declined. But it also declined in other countries that beat the US in the international rankings, such as Japan and the United Kingdom, and those declines were even steeper. That suggests that even if the poor math scores held the US back, other factors were ultimately more important.
The US also scores near the top on the Global Entrepreneurship Monitor, a survey that asks people around the world about their likelihood of starting a business. That suggests that, even if Americans aren't the best at applying their reading and math skills in the real world, they're likely to try to take the plunge into business ownership anyway.
In fact, economic growth in the US has generally outpaced what would be expected from its test scores, according to Hanushek's research. Hanushek attributes the better-than-expected results to free-market economic policies, and warns that other nations have imitated the US and are likely to catch up in the future.
But it's also possible that the US has other advantages built into the education system — and if it's those advantages that have made the US an outlier, then there's reason to be concerned about the falling PISA scores. First, education was democratized earlier in the US than in other countries. Even if the US was lagging behind as early as the '60s, it was often educating a broader swath people than other nations. Second, the US has long led the world in educational attainment. Even if students weren't testing as well on what they learned, they outstripped their peers in other countries on earning high school and college degrees.
Those advantages are disappearing. And if they were propping up US educational attainment, the PISA results really could be a predictor of worse economic news down the road.