Limited Attention as the Bound on Rationality

A utility maximizing model of allocating limited attention between adopting new behaviors and adapting current behaviors generates an optimal policy that resembles commonly observed, and apparently irrational, behavioral rules. The ability to update current behaviors implies an endogenous opportunity cost of adopting a new behavior. If this cost is sufficiently high, then behaviors are less than substantively rational. However, if this high cost of attention is ignored, then behaviors are less rational than if this cost is considered. This is because more rational behaviors are updated less frequently and so economize on attention in the future.