When food stamps are included as income, the number of households in extreme poverty, defined as living on $2 a day, drops to 800,000, Shaefer says. That's up from 475,000 in 1996. "This seems to be a group that has fallen through the cracks," says Kathryn Edin, a Harvard researcher and professor of public policy. The study found that among households in extreme poverty, one in five received rent vouchers or lived in public housing. Sixty-six percent had at least one child with public health insurance. The study did not factor in how those benefits affect household income.