Indeed, as rents have spiked in Philadelphia, concerns about affordability have increasingly emerged. Philadelphia has the highest rate of deep poverty — people with incomes below half the poverty line — of any of the nation's 10-most-populous cities, the U.S. Census Bureau found in 2014. According to census data, Philadelphia's deep-poverty rate is 12.3 percent, while the city's overall poverty rate is about 26 percent. A family of four is in poverty if it has a cash income of about $24,000, while deep poverty is defined by that same family taking in $12,000 or less.