To survive in Philadelphia without food stamps or other government assistance, a family of four needs to make nearly $60,000 a year — a shocking number that shows how expensive life has become. According to a study, two adults with one preschooler and one school-age child have to take in $59,501 a year to live on a bare-bones budget in the city. In 2008, the same family of four needed $53,611 to make it in Philadelphia. The problem is that nearly 62 percent of Philadelphia households take in less than $50,000 a year, according to census data analyzed by Dave Elesh, a sociologist at Temple.