A new U.S. Census-based Pew Research Center study says a record 40% of households with children include "breadwinner moms." They are the primary source of income for households with children younger than 18. These moms include two groups: 5.1 million (37%) are married mothers who have a higher income than their husbands, and 8.6 million (63%) are single mothers. The median family income for the first group was $79,800 in 2011, compared with $23,000 for the single mothers.