With 1.3 million workers, there's no bigger, or more closely followed, employer in America than Walmart, and Kristin Oliver is the HR executive responsible for all of them. In an exclusive interview with Forbes' Paul Noglows at the Forbes Reinventing America Summit in Detroit this month, she talked about the company's recent decision to raise their minimum wage, the decision-making process behind it, and why she thinks Walmart and other employers are increasingly recognizing that they have a responsibility to help those at the lower end of the economic scale. "...