Roxie Bauer has raised a daughter – mostly by herself – paid a mortgage for more than 25 years and paid off her car, all on a checker's paycheck from Vons. Bauer, after 29 years with the supermarket, earns $17.90 an hour, has good health benefits and a pension plan. But life stories like hers are rare these days, and she knows it. "We are dinosaurs," Bauer said of herself and others in her position. "I don't have a formal education, but I've been able to eke out a decent living." Fundamental changes in the economy over the last two...