In 1976, the year Josh Schwartz was born in Providence, one tenth of one percent of American households controlled 7.5 percent of the nation’s wealth. By 1995, the year Schwartz graduated from a private, arts-oriented high school, that share had risen to 13.5 percent. By 2003, when the Schwartz-penned high school drama The O.C. premiered on Fox, it was at 15.9 percent; by 2007, when the Schwartz-produced Gossip Girl premiered...