Based on six years of reporting, Paul Tough's new book "The Years That Matter Most: How College Makes or Breaks Us" explores whether higher education in the U.S. still delivers on its promise of social mobility. Tough takes on the so-called "admissions industrial complex" that favors students from wealthier backgrounds and looks at why the most selective U.S. colleges have become the least socio-economically diverse. We'll talk to Tough about what he uncovered in over 100 interviews with students, parents, professors and admissions officers.