Why People Buy Stuff They Don't Need

• people buy unnecessary features because of two cognitive errors -- they overestimate the risk that a product without such features will become obsolete, and they overestimate the likelihood that they will learn to use the new features.
• parents, especially poor parents, tend to buy products they cannot afford because they are acutely focused on whether their children are fitting into peer groups....[T]hey are acutely sensitive to how certain consumer products influence their children's "search for dignity."