Another possible explanation: Parents are kicking in less of money for college. Parents still pay for most of the average family’s total college expenses. But their contribution, including from savings, income and loans, averaged 37% in 2011, down from 47% the year before, according to the “How America Pays for College” survey by student-loan company Sallie Mae. “Kids used to rely on the bank of mom and dad,” Descano says. “So many families are trying to work themselves out of the financial impact of the Great Recession.”