This thesis consists of three self-contained essays. Essay I: Why do consumers’ expenditure patterns matter for their inflation expectations? I propose a model of rational inattention where a consumer trades off paying attention between goods bought more or less frequently. For each good purchased, the consumer observes the rate of price change with an error that depends on the frequency at which the good is purchased. Goods bought less frequently are observed with a greater level of error. I apply a simple version of the model where the inflation index is decomposed into two sub-index components; one sub-index contains goods bought often, and the other contains goods that are not bought often. My results show that the consumer pays more at...