The United States bills itself as a land of opportunity; where economic and social advancement depend on abilities, skills, and drive, rather than the circumstances into which one is born. But is this characterization accurate? How does the U.S. compare to other countries in terms of socio-economic mobility across generations? And does the ability to change one's economic lot differ much by race, income, and national origin? Steven Durlauf of the Harris School, at the University of Chicago jo...