But in the northern European countries that have fared better, the picture was brighter — and the study credits continuing education. In Finland, Denmark, and the Netherlands, more than 60 percent of adults took part is either job training or continuing education. In Italy, by contrast, the rate was half that.
As the American economy sputters along and many people live paycheck-to-paycheck, economists say a highly-skilled workforce is key to economic recovery. The median hourly wage of workers scoring on the highest level in literacy on the test is more than 60 percent higher than for workers scoring at the lowest level, and those with low literacy skills were more than twice as likely to be unemployed.
"It's not just the kids who require more and more preparation to get access to the economy, it's more and more the adults don't have the skills to stay in it," said Anthony Carnevale, director of the Georgetown University Center on Education and the Workforce.
Education Secretary Arne Duncan said in a statement the nation needs to find ways to reach more adults to upgrade their skills. Otherwise, he said, "no matter how hard they work, these adults will be stuck, unable to support their families and contribute fully to our country. "
Among the other findings:
—Americans scored toward the bottom in the category of problem solving in a technology rich environment. The top five scores in the areas were from Japan, Finland, Australia, Sweden and Norway, while the U.S. score was on par with England, Estonia, Ireland and Poland. In nearly all countries, at least 10 percent of adults lacked the most basic of computer skills such as using a mouse.
—Japanese and Dutch adults who were ages 25 to 34 and only completed high school easily outperformed Italian or Spanish university graduates of the same age.