"But as women's careers and earnings have taken off, their contributions have swelled Social Security's coffers. "Men and women are living longer, and women's contributions to the system have paid for that," Mulligan says. "When Social Security was founded, people weren't expected to be retired [...]

"Equally troubling is the lingering occupational gender segregation that systematically disadvantages women and perpetuates the gender gap in both yearly and lifetime earnings. Gwen Sharp at Sociological Images finds that women make up about half of the total paid workforce but only hold a quarter [...]

"Single mothers are especially struggling. In another report from the Institute of Women's Policy Research, 66 percent said they failed to pay bills within the past year, 44 percent had difficulty paying rent or making mortgage payments, and 80 percent of single mothers said they [...]