We present a theory of price and quality decisions by managers who are self-serving. In the theory, firms stress the price or quality of their products, but not both. Accounting for this, managers exploit any uncertainty about the cause of market outcomes to credit surprisingly positive results to the dominant, “strategic” factor and blame surprisingly negative results on the lesser factor—as doing so is psychologically rewarding. The problem with biased attributions, however, is that they prompt biased decisions. We motivate this argument with experimental evidence and then develop a model to understand the cost of the bias under different market conditions. Counter to intuition, we find that firms in a competitive setting can profit from the self-serving nature of their managers.