The United States is in "a real state of crisis," Secretary of Education Arne Duncan said Tuesday. A study based on tests developed by the Organization for Economic Cooperation and Development, a coalition of mostly industrialized countries, showed that American adults fare poorly in mathematical and technical skills needed for a modern workplace compared to their counterparts in most other developed nations. The exams were administered to 166,000 people, ages 16 through 65, in 23 countries in 2011 and 2012. Results show a startling pattern of the United States lagging behind several other countries, starting with test scores and young adults' graduation rates and later corresponding to a skills gap after graduation. "We have a real state of crisis. This is much bigger than education," he said at a panel at fourth-annual Education Nation Summit. "We have to close what I call the opportunity gap. The gap between the haves and the have-nots is far too wide."