The rise of the knowledge economy over the past several decades has forever changed the nature of work and, by extension, the class structure of advanced cities and societies. Living standards among the working class has declined sharply as the economy has deindustrialized. Across the United States, work itself has split into two major categories and classes: high-skill, high-pay creative work, involving new ideas and new technology; and low-skill, low-pay service work. As workers’ incomes and expectations have diverged, so too have their residential choices. Middle-class neighborhoods, like middle-class paychecks, are increasingly hard to find.