Philadelphia has the highest rate of deep poverty - people with incomes below half of the poverty line - of any of the nation's 10 most populous cities.
The annual salary for a single person at half the poverty line is around $5,700; for a family of four, it's around $11,700.
Philadelphia's deep-poverty rate is 12.9 percent, or around 200,000 people.
Phoenix, Chicago, and Dallas are the nearest to Philadelphia, with deep-poverty rates of more than 10 percent.
The numbers come from an examination of the 2009 through 2011 three-year estimate of the U.S. Census American Community Survey by The Inquirer and Temple University sociologist David Elesh.
Of the 4,300,000 people living in the area around Philadelphia, there are nearly 160,000 in deep poverty - a rate of 3.6 percent - in Bucks, Chester, Montgomery, Delaware, Salem, Gloucester, Burlington, and Camden Counties as well as New Castle County, Del., and Cecil County, Md., Elesh's analysis showed.
Nationwide, more than 20 million people live in deep poverty, according to the Center on Budget and Policy Priorities.
These deep-poverty numbers don't include noncash benefits such as food stamps, which help families survive, experts said.
The Philadelphia deep-poverty figure wasn't a complete surprise for antipoverty advocates, since the city already has the highest poverty rate - 28.4 percent - of any of America's biggest cities.
Still, it's significant, because while many people who live just below the poverty line often move out of poverty, those in deep poverty are in such a profoundly disadvantaged state that they're more likely to stay mired in it, according to Judith Levine, a Temple sociologist. "Poverty becomes a long-term experience, and it's very different, especially for children," she said.
Children in deep poverty do worse in school than less poor kids, said Arloc Sherman, researcher with the Center on Budget and Policy Priorities.
"The consequences may last decades," he said.
Sherman added that it is difficult to imagine how someone living in deep poverty gets by.
"It's so stressful," said Emily Edwards, 29, who is sleeping at night on the floor of a friend's apartment in Germantown while her 4-year-old son sleeps near her on a mattress.
Edwards has tried to survive by working as a massage therapist. She managed, with the help of an academic researcher, to get a small grant from the University of Pennsylvania for a part-time job checking soda and tobacco advertising in corner stores.
But that ended, and she now has zero income and receives $315 a month in cash assistance (welfare) and $300 a month in food stamps. That comes to around $7,400 a year, less than half the $15,510 poverty rate for a family of two.
"I worry about my son, a job, housing, food," she said. "I feel hopeless and overwhelmed."
Philadelphians in deep poverty live without running water or electricity or heat for long periods of time, according to Mariana Chilton, a nationally recognized expert on poverty at Drexel University's School of Public Health.
"It forces them to live in toxic stress," Chilton said. "There's no break, no ability to bounce back. They're dealing with social dysfunction, violence in the family, potential drug addiction, poor education."
What results, said Robert Fairbanks, a social-policy expert who teaches at the University of Chicago and has studied drug-recovery houses in Kensington, is a bifurcated city: "Philadelphia is a gorgeous city downtown, but north of it, all the lights on the grid are turned off."
Unless one has experienced the absolute deprivation of deep poverty, "you just don't know this," said Deisha Bradley, 30, a North Philadelphia mother of a 3-year-old girl who was recently laid off from a job as a security guard and now has no income. She may not get state unemployment insurance because she worked part-time. She receives $358 a month in food stamps, the equivalent of around $4,200 annually, nearly one-fourth the poverty rate for a family of two.
"I won't let my daughter see me upset," said Bradley, who lives in a $550-a-month apartment. "We do without new clothes, and I won't eat when there's only a little food left." She said she has not applied for welfare because the benefit is not large.
Many people don't bother to apply for welfare anymore, said Kathryn Edin, public-policy professor at the Harvard Kennedy School of Government. "Word on the street is, welfare is dead," she said. "It's not seen as a meaningful option."
While there are more than 46 million poor Americans, just 4.4 million are on welfare - 3.3 million of them children, federal figures show.
Cuts to programs that advocates say have worked - including General Assistance in Pennsylvania - "wind up harming people," said Julie Zaebst, interim director of the Greater Philadelphia Coalition Against Hunger.
The new federal budget proposed by U.S. Rep. Paul Ryan (R., Wis.) would cut the SNAP program (the new name for food stamps) by tens of billions of dollars. Sometimes, SNAP is all people have, said Zaebst: Nine percent of Pennsylvania households getting food stamps report zero income.
Ultimately, moving people out of deep poverty helps everyone, said Eva Gladstein, executive director of Mayor Nutter's Office of Community Empowerment and Opportunity. "We need as many Philadelphians as possible earning decent wages, investing in homes, and contributing to the overall wealth of the city. If people can't afford to pay taxes, it affects every one of us."