Models with imperfect information that generate persistent monetary nonneutrality predominantly rely on assumptions leading to substantial heterogeneity of information across price-setters. This paper develops a quantitative general equilibrium model in which the degree of heterogeneity of information is determined endogenously. In the model, firms use two technologies to acquire information: costly updating to full information and costless learning from publicly observed market signals. Price changes of firms that update information infrequently are synchronized with market...