The United States has slipped behind many other countries in college completion and "educational mobility," with fewer young Americans getting more education than their parents, according to the Organization for Economic Cooperation and Development's "Education at a Glance" report.

U.S. college graduation rates rank 19th out of 28 countries studied by the OECD, which tracks education investment and performance of wealthier democracies, said OECD Director for Education and Skills Andreas Schleicher.

The lack of educational mobility has serious implications for individuals and society, he noted. Higher education levels are associated not just with higher earnings, but also with better health, more community engagement and more trust in governments, institutions and other people.