Here’s a puzzle: if U.S. students do so badly on international tests, especially in math, how can it be that the U.S. economy is so strong? An educated workforce is supposedly a big predictor of a country’s income and annual growth. Yet the performance of American 15-year-olds on the Program for International Student Assessment, or PISA, has always been lackluster. Since 2012, U.S. math scores have slumped down into the bottom half. Meanwhile, the U.S. remains the top economy in the world this year with over $19 trillion of goods and services produced. No other country even comes close.
A group of behavioral economists wondered if U.S. students are actually not as incompetent as their scores would suggest, but simply lazy when they’re taking the PISA exam. To test this, they created a PISA-like exam of just 25 questions and asked 447 sophomores at two different high schools to take it. Seconds before the test started, they surprised half the students at each school with an envelope of 25 one-dollar bills. The researchers told those students they would take away one dollar for each incorrect or unanswered question.
Guess what? Scores rose for the American teens who were bribed. The economists estimated that if U.S. students had put this much effort into the real PISA test, they would have scored 22 to 24 points higher in math, moving the U.S. from 36th to 19th in the 2012 international rankings. (The U.S. ranked 39th in 2015.)
The researchers conducted the same experiment in Shanghai, China, where students had posted the highest scores in the world on the actual 2012 PISA test. However, the bribe (in renminbi instead of U.S. dollars) didn’t make a difference. The bribed Chinese students scored the same as those who weren’t bribed. They both got almost twice as many questions right as the incentivized American students. (Click here if you want to try the test yourself.)
“We’re by no means fully closing the gap,” said Sally Sadoff, a behavioral economist at the Rady School of Management at the University of California at San Diego and one of six authors of the study. “But the incentive is a tool to show that U.S. students aren’t really trying as hard as they could.”
“We’re not saying we should throw out PISA. But the gaps we see are not just about ability, but [about] some combination of ability and motivation,” Sadoff added.
The working paper, “Measuring Success in Education: The Role of Effort on the Test Itself,” was distributed by the National Bureau of Economic Research in November 2017.
There’s no reason for U.S. students to try their best on the PISA test. It won’t help them get into college. They don’t even get to see their individual scores afterward. But the scores often influence policymakers. Often, there’s a rush to copy the educational models of countries that rank at the top. Or there are policy debates inside a country when scores slide.