These figures come from the annual survey of education from the Organization for Economic Cooperation and Development, or O.E.C.D., and it should be a shock to Americans.

A basic element of the American dream is equal access to education as the lubricant of social and economic mobility. But the American dream seems to have emigrated because many countries do better than the United States in educational mobility, according to the O.E.C.D. study.

As recently as 2000, the United States still ranked second in the share of the population with a college degree. Now we have dropped to fifth. Among 25-to-34-year-olds — a glimpse of how we will rank in the future — we rank 12th, while once-impoverished South Korea tops the list.

A new Pew survey finds that Americans consider the greatest threat to our country to be the growing gap between the rich and poor. Yet we have constructed an education system, dependent on local property taxes, that provides great schools for the rich kids in the suburbs who need the least help, and broken, dangerous schools for inner-city children who desperately need a helping hand. Too often, America’s education system amplifies not opportunity but inequality.

My dad was a World War II refugee who fled Ukraine and Romania and eventually made his way to France. He spoke perfect French, and Paris would have been a natural place to settle. But he felt that France was stratified and would offer little opportunity to a penniless Eastern European refugee, or even to his children a generation later, so he set out for the United States. He didn’t speak English, but, on arrival in 1951, he bought a copy of the Sunday edition of The New York Times and began to teach himself — and then he worked his way through Reed College and the University of Chicago, earning a Ph.D. and becoming a university professor.