I heard author Robert Perrucci speak about the 'double-diamond U. S. class system at the recent Diversity Summit. As a result she briefly engaged the author in conversation and then requested his book through Interlibrary Loan. Perrucci and Wysong hold a very pessimistic view on any potential for 'upward mobility' in the United States...and as such their findings fly in the face of conventional wisdom. A hard book to read, but worth attempting for anyone wishing to engage in public policy debates.