Prices tend to remain constant for a period of time and then jump. In the literature, this “rigidity” is usually interpreted to reflect a cost of adjusting prices. This article shows that price rigidity can alternatively reflect optimal price setting when there are no adjustment costs, namely, if the seller is rationally inattentive. The model generates non-trivial pricing patterns that are consistent with the data and that are hard to explain with the traditional adjustment-cost model. In particular, prices are adjusted frequently but move back and forth between a few given values, hazard functions are downward sloping, and responses to persistent shocks are sluggish. These results are obtained in a model that implements rational inattention without simplifying assumptions on the functional forms of the processed signals.

We study a market with rationally inattentive consumers who are unsure of the terms of the offers made by firms, but can acquire information about the terms at a cost. In a symmetric equilibrium, the price set by firms is continuously increasing in the cost of information for consumers and decreasing in the number of firms operating. In addition, favorable a priori information about a firm leads it to set a higher price, and a new entrant can increase demand for incumbents. When consumers have heterogeneous costs of information, firms selling low-quality products may choose to set the highest prices.

Abstract Individuals are constantly processing external information and translating it into actions. This draws on limited resources of attention and requires economizing on attention devoted to signals related to economic behaviour. A natural measure of such costs is based on Shannon’s “channel capacity”. Modelling economic agents as constrained by Shannon capacity as they process freely available information turns out to imply that discretely distributed actions, and thus actions that persist across repetitions of the same decision problem, are very likely to emerge in settings that without information costs would imply continuously distributed behaviour. We show how these results apply to the behaviour of an investor choosing portfolio allocations, as well as to some mathematically simpler “tracking” problems that illustrate the mechanism. Trying to use costs of adjustment to explain “stickiness” of actions when interpreting the behaviour in our economic examples would lead to mistaken conclusions.

We integrate tools to monitor information acquisition in field experiments on discrimination and examine whether gaps arise already when decision makers choose the effort level for reading an application. In both countries we study, negatively stereotyped minority names reduce employers' effort to inspect resumes. In contrast, minority names increase information acquisition in the rental housing market. Both results are consistent with a model of endogenous allocation of costly attention, which magnifies the role of prior beliefs and preferences beyond the one considered in standard models of discrimination. The findings have implications for magnitude of discrimination, returns to human capital and policy. (JEL C93, D83, J15, J16, J24, J71, R31)