The economist who first warned the US about the K-shaped economy says he sees the potential for the situation to get worse. Peter Atwater, the economist who's often credited with popularizing the idea of a K-shaped recovery—in which high earners thrive while lower-income Americans struggle—said one of his biggest concerns about the growing divide between the upper- and lower-income households is that the situation leads to a "caste system," he told Business Insider. "What sustains a caste